Showing posts with label cesareans. Show all posts
Showing posts with label cesareans. Show all posts

Friday, November 2, 2018

The High Price of Multiple Cesareans


A recent study once again reinforces the message that the more cesareans are done, the higher the risk for complications.

In previous posts, we have mostly discussed cesarean risks in terms of future pregnancies. We have written about Placenta Accreta Spectrum several times here already. This is where the placenta implants too deeply into the uterus. This is a life-threatening potential complication of pregnancies after cesareans, and the risk goes up with the number of prior cesareans. 

However, the risks with multiple cesareans aren't limited only to future pregnancies.

This new study highlights that the risk for other problems occurring during and after surgery also rises with the number of prior cesareans. The study found that: 
  • After 2 cesareans, the risk for organ injury and hysterectomy increased
  • After 3 cesareans, the risk for hemorrhage (massive bleeding) and surgical site complications increased
Injuries to organs around the area are serious because they usually involve the bladder or intestines. The more abdominal surgery someone has, the greater the risk for adhesions, scar tissue that can cause internal organs to stick together. This can make it difficult to operate in the area without causing collateral damage to organs nearby. If organ injury occurs, it can have lifelong consequences for the mother's urinary and/or G.I. system. Even if organ injury does not occur, adhesions alone can cause significant pain. For some people, it causes life-long severe pain. 

Obviously, the risk for major bleeding increases with surgery. Each successive surgery takes longer because of the scar tissue, and that increases the risk of hemorrhage even more. Some women need blood transfusions during or after the surgery. Many suffer problems with anemia, which can affect milk supply. Those with very severe hemorrhages may even experience Sheehan's Syndrome, life-long endocrinological problems because severe bleeding affected the pituitary gland. 

The risk for completely losing your uterus (hysterectomy) also increases with more cesareans. This is usually due to cases of accreta or in response to severe bleeding. The placenta cannot detach properly with accreta, or the uterus doesn't clamp down properly during surgery and the bleeding can't be stopped. Often the only way to keep the mother alive may be to take her uterus out, forever altering her fertility. . 

In addition, surgical site complications increase with each surgery. These can include infections, which can go septic and spread to the entire body. Although rare, some women die due to infections after cesareans. Others lose their uterus. Other surgical complications include seromas and hematomas (pockets of fluid or blood around the wound), and the surgical wound not healing (dehiscence). While these can be treated, they often cause long-term wounds and a painful recovery. They complicate recovery and make mothering difficult.

The Take Away Message

Sometimes when cesareans are questioned, people get all defensive. Mothers who had their babies by cesarean may feel like they are being judged or that some may think them less of a mother because of their cesarean. Doctors may feel defensive and point out the many times that cesareans have saved lives.

That's not what this is about. This is not about any one person's cesarean or a judgment about whether that cesarean was necessary or lifesaving. This is a public health issue about the overuse of cesareans and the potential consequences of that. The take away message here is:
All of the potential complications of cesareans need to be taken more seriously and cesareans used only when truly necessary. 
Cesareans are not evil. They can be a wonderful, life-saving intervention, and no one should feel like less of a mother because they had a cesarean. However, cesareans do carry risk. When overused or done without need, they can cause severe problems and even death, especially when multiple repeat cesareans are being done. 

National Public Radio has been running an excellent series on maternal mortality in pregnancy, as well as on near-misses (where the mother almost dies during or just after pregnancy), that highlights many of these complications: 
...according to the CDC, the rate at which women are suffering nearly fatal experiences in childbirth has risen faster than the rate at which they're dying. Based on the rate per 10,000 deliveries, serious complications more than doubled from 1993 to 2014, driven largely by a fivefold rise in blood transfusions. That also includes a nearly 60 percent rise in emergency hysterectomies — removal of the uterus and sometimes other reproductive organs, often to stem massive bleeding or infection. In 2014 alone, more than 4,000 women had emergency hysterectomies, rendering them permanently unable to carry a child. The rate of new mothers requiring breathing tubes increased by 75 percent, as did the rate of those treated for sepsis, a life-threatening inflammatory response to infection that can damage tissues and organs. 
"These numbers are really high, and far too many of them are preventable," said Dr. Elliott Main, medical director of the California Maternal Quality Care Collaborative and a national leader in efforts to reduce maternal deaths and injuries...
...more than 135 expectant and new mothers a day — or roughly 50,000 a year, according to the Centers for Disease Control and Prevention — endure dangerous and even life-threatening complications that often leave them wounded, weakened, traumatized, financially devastated, unable to bear more children, or searching in vain for answers about what went wrong.
Although certainly not the only factor in the rising rate of complications, many of these near-death and fatal experiences begin with cesareans. The same NPR article noted:
Only about one-third of U.S. C-sections are medically justified, according to [Eugene]  DeClercq, the Boston University maternal health expert. A web of factors explains the rest, including hospital culture (C-section rates vary widely from one institution to the next); efforts to make childbirth more convenient (C-sections can be scheduled); and indirect financial incentives. Because C-sections normally take much less time than vaginal deliveries, they are more cost-effective for hospitals and providers. Additionally, several studies point to the influence of "defensive medicine," a term for doctors' fears of being blamed by their patients for not having done everything possible to avoid medical problems.
The culture of cesareans is strong in many hospitals, and as a result many unnecessary cesareans are being done. And once a woman has had a cesarean, she is often pressured into further cesareans by doctors who say Vaginal Birth After Cesarean (VBAC) is "too risky." But the fact is that multiple repeat cesareans are not risk-free either. Both VBAC and Repeat Cesarean have risks to mother and baby that must be carefully weighed. It should be up to the mother to decide which choice to pursue.

Research is clear that taken as a group, cesareans are not risk-free and should not be taken lightly or done routinely. 



References

Am J Perinatol. 2018 Oct 29. doi: 10.1055/s-0038-1673653. [Epub ahead of print] Risk of Maternal Morbidity with Increasing Number of Cesareans. Sondgeroth KE, Wan L, Rampersad RM, Stout MJ, Macones GA, Cahill AG, Tuuli MG. PMID: 30372778
OBJECTIVE: To estimate the risk of perioperative morbidity with increasing number of cesareans. STUDY DESIGN: We conducted a retrospective cohort study from 2004 to 2010. Patients delivered by cesarean were included. Outcome measures were a composite organ injury (bowel or bladder), hysterectomy, hemorrhage requiring transfusion, severe morbidity, or surgical site complications... RESULTS: Of the 15,872 women in the cohort, 5,144 had cesarean delivery: 3,113 primary, 1,310 one prior, 510 two prior, and 211 three or more prior cesareans. There was a significant increase in organ injury, hysterectomy, and surgical site complications with increasing number of cesareans. In multivariable analysis, the risk of organ injury and hysterectomy was increased compared with primary cesarean after two prior cesareans, and after three or more cesareans for hemorrhage requiring transfusion and surgical site complications. CONCLUSION: The risks of organ injury and hysterectomy are increased after two or more prior cesareans, and risks of hemorrhage and surgical site complications are increased after three or more cesareans.
Arch Gynecol Obstet. 2017 Feb;295(2):303-311. doi: 10.1007/s00404-016-4221-8. Epub 2016 Oct 21. Incidence of adhesions and maternal and neonatal morbidity after repeat cesarean section. Arlier S, Seyfettinoğlu S, Yilmaz E, Nazik H, Adıgüzel C, Eskimez E, Hürriyetoğlu Ş, Yücel O. PMID: 27770246
PURPOSE OF INVESTIGATION: We investigated the effect of repeat cesarean sections (CSs) and intra-abdominal adhesions on neonatal and maternal morbidity. MATERIALS AND METHODS: We  analyzed intra-abdominal adhesions of 672 patients. RESULTS: Among the patients, 173, 206, 151, and 142 underwent CS for the first, second, third, and fourth time or more, respectively. There were adhesions in 393 (58.5 %) patients. Among first CSs, there were no adhesions, the rate of maternal morbidity [Morales et al. (Am J Obstet Gynecol 196(5):461, 2007)] was 26 %, and the rate of neonatal morbidity (NM) was 35 %. Among women who have history of two CSs, the adhesion rate was 66.3 %, the adhesion score was 2.05, MM was 14 %, and NM was 21 %. Among third CSs, these values were 82.1, 2.82, 23, and 14 %, respectively. Among women who have history of four or more CSs, these values were 92.2, 4.72, 31.7, and 18 %, respectively. Adhesion sites and dense fibrous adhesions increased parallel to the number of subsequent CSs. Increased adhesion score was associated with 1.175-fold higher odds of NM and 1.29-fold higher odds of MM. The rate of NM was eightfold higher in emergency-delivered newborns (emergency: 39.4, 40 %; elective: 4.9 %). MM was 20 and 26 % for elective and emergency CSs, respectively. CONCLUSIONS: Emergency operations and adhesions increased complications.

Tuesday, October 9, 2018

Women Are Dying From This: Taking Cesareans Seriously


When women have cesareans, they are rarely warned that a possible complication can be placental problems in future pregnancies.

Many women (and especially higher weight women) are pressured into cesareans in their first pregnancy. Many of these same women are counseled away from Vaginal Birth After Cesarean (VBAC) and into repeat cesareans in subsequent pregnancies.

Few of these women have been told that cesareans raise the risk for Placenta Accreta, a very serious complication, and that every cesarean increases the risk for it. I know *I* wasn't told this. This is a tremendous disservice to parents and to the importance of informed consent.

About Accreta

In Placenta Accreta, the fertilized egg implants near or on scar tissue in the uterus. This scar tissue is usually from a prior cesarean, but can also be from a D&C procedure, fibroid removals, a perforation from an IUD, or any uterine surgery or instrumentation. The placenta then grows into the uterine wall in this scar tissue. After the baby is born (often prematurely), the placenta can't separate properly and bleeding can become prolific. If the bleeding is not resolved, the mother can die.

There are degrees of Placenta Accreta. When the placenta grows into the uterine wall, that's Placenta Accreta. 

When the placenta invades the muscles of the uterus, that's known as Placenta Increta.

When the placenta grows through the uterine wall and into nearby organs like the bladder, that's called Placenta Percreta. All are extremely serious conditions, but percreta is the most serious of all.

The accreta rate has risen over the years as the cesarean rate has increased. Doctors are seeing more and more cases these days of what used to be a very rare complication. Some data indicate that the accreta rate has risen from about 1 in 4000 in the 1970s to about 1 in 533 now.

You can read more about this in my blog series on Placenta Accreta.
  • Part One - What Is Placenta Accreta?
  • Part Two - Life-Threatening Complication of Prior Cesarean 
  • Part Three - Risks to Mother and Baby
  • Part Four - Diagnosis, Treatment, and a Cautionary Story
The absolute numerical risk of accreta occurring in any one person is low, even with prior cesareans. Most women who have had cesareans will not experience an accreta. However, it is such a life-threatening condition that even a relatively small incidence carries a tremendous burden of complications, cost, and potential loss of life.

The more cesareans you have had, the greater the risk for accreta. In one very large study (Silver 2006), accreta was present in:
  • 0.24% of women undergoing their first cesarean (previously unscarred)
  • 0.31% of women undergoing their second cesarean (one prior cesarean)
  • 0.57% of women undergoing their third cesarean (two prior cesareans)
  • 2.13% of women undergoing their fourth cesarean (three prior cesareans)
  • 2.33% of women undergoing their fifth cesarean (four prior cesareans)
  • 6.74% of women undergoing their sixth or more cesarean (five or more prior cesareans)
This is why it is important to avoid automatic repeat cesareans and to keep VBAC a viable choice. Multiple repeat cesareans are the single most preventable factor for accretas. 

Accreta does sometimes occur after only one cesarean, like the woman in the video below, and that's why it's important to prevent a first cesarean whenever possible as well.

One Mother's Accreta Story

This mother had only had ONE prior cesarean, but still developed accreta with baby #2. Her first cesarean was a planned cesarean, urged by her OB. She was never warned that her cesarean meant accreta was a potential risk for the future.

THIS is why the high cesarean rate matters. On a case-by-case basis, a cesarean can be a good thing. But the public health implication of a high cesarean rate is that more women will develop life-threatening complications like placenta accreta, more babies will be born prematurely, and more women will die or experience permanent damage. Sometimes even after only one cesarean.

If we want to decrease maternal mortality rates and prevent complications from accreta, we MUST decrease cesarean rates. As the mother in the video below states:
A cesarean can be a life-saving intervention. The goal is not to eliminate cesareans. The goal is to make decisions regarding cesareans appropriately, and to recognize that even an uncomplicated cesarean and recovery can still put the mother at significant future risk....


She continues:
"There are too many cesareans now, 1 in 3 births, and researchers estimate that as many as 50% of those are unnecessary. 
And since a prior cesarean is a significant risk factor for developing a future accreta, that means that there are women developing accreta when it could have been prevented. So the easiest way to reduce the amount of accretas is to reduce cesarean levels... 
Women are dying from this, and mothers are dying from this. We need to take the risks of a cesarean seriously."


Thursday, April 19, 2018

VBAC after Cesarean for Arrest of Descent or Cephalo-Pelvic Disproportion

Your pelvis is NOT defective
A cesarean for "Arrest of Descent" means a cesarean done after a woman has dilated fully and pushed for a while without the baby descending. The amount of pushing time required for the diagnosis varies from source to source but is usually at least 1-3 hours.

When a woman has a cesarean for Arrest of Descent, she is often told something is wrong with her pelvis. She might be told she has:
  • A "flat" sacrum 
  • A "prominent" sacrum
  • A pubic arch that is "too narrow"
  • Ischial spines that are "too prominent" 
  • A pelvis that is "too small"
  • "Too much soft tissue" (fat) lining the vagina/pelvis
  • A pelvis that is the "wrong shape" 
  • A baby that was "too big" for her pelvis 
  • "Cephalo-Pelvic Disproportion" (baby too big and pelvis too small, causing baby to not fit)
Often women who have been told these things are strongly discouraged from trying for a Vaginal Birth After Cesarean (VBAC). There are documented cases where women have been told their pelvis is too flat or too small to have a VBAC, that they have "soft tissue dystocia" (a.k.a. "fat vagina"), that their pelvis is the wrong shape, or that since they couldn't push out a baby before, chances are they never will be able to because CPD is a recurring condition:
Yesterday, at my appt, while speaking with one of the midwives - she asked if I wanted her honest opinion & that if I was unable to push out a 7 and 1/2 pound baby and 2nd babies are normally larger then she didn't think it would be successful. 
The bottom line is that providers that are not truly VBAC-supportive often make women believe that something is wrong with their bodies and that they have little chance of having a vaginal birth, implying it's better just to schedule a repeat cesarean. Then the care providers conveniently have fewer VBAC labors to attend.

However, many women who have been told they have an abnormal pelvis or soft tissue dystocia or who have had a cesarean for Arrest of Descent or CPD have gone on to have VBACs anyhow.

And a new study just out confirms that many women with a prior cesarean for Arrest of Descent do indeed go on to have a VBAC and should not be discouraged from trying.

New Study on VBAC after Arrest of Descent

A recent American study (Fox 2018) shows that VBAC after prior Arrest of Descent is often successful.

In the study, one hundred women who had one prior cesarean for Arrest of Descent had a "Trial Of Labor After Cesarean" (TOLAC or TOL). A whopping 84% ended up having a VBAC. This is an excellent rate and better on average than many VBAC studies.

The authors concluded (my emphasis):
This suggests that arrest of descent is mostly dependent on factors unique to each pregnancy and not due to an inadequate pelvis or recurring conditions. Women with a prior CD [Cesarean Delivery] for arrest of descent should not be discouraged from attempting TOLAC in a subsequent pregnancy due to concerns about the likelihood of success.
The fact that the authors state this so strongly in an obstetrics journal is a big deal because it goes against what is commonly taught to many OBs, so let's reemphasize those points:
  • Arrest of Descent is NOT usually due to an inadequate pelvis
  • "CPD" is not necessarily a recurring condition
  • Women with this history should not be discouraged from trying for a VBAC
Many women can and DO have VBACs after diagnoses of CPD and Arrest of Descent. Yet strong discouragement away from VBAC is exactly what happens to many of these women, even today. 

Other Similar Studies

Was this study just a fluke? What do other studies on Arrest of Descent say?

There are only a couple of studies that specifically use the term "VBAC after Arrest of Descent" so you have widen the search a bit. Other search terms to consider include "CPD + cesarean," "cesareans after full dilation," or "cesareans done during second stage of labor" (pushing), or "prolonged second stage," or similar terms. Carefully vetted, these are essentially Arrest of Descent cesareans too.

If you just look at studies that examine VBAC after a cesarean for CPD, research reviews show that about two-thirds of women will have a VBAC. This rate is lower than for those whose first cesarean was for breech or fetal distress, but is still a very good rate. If all those women had been discouraged from VBAC or pressured into repeat cesareans, two-thirds of them would have had unnecessary cesareans!

There is very little data on women who have had more than one cesarean for CPD. However, one 1989 study did contain some data on women like this. If you crunch the data in the full text of the study, women with 2 prior cesareans for CPD had a 56% VBAC rate. So although we don't have a lot of data on this, what we do have suggests that even among women with more than one cesarean for CPD, more than half will have a VBAC.

The doctors who like to discourage VBAC cite a discouraging 1997 study that found a low VBAC rate (13%) in women who had reached full dilation and pushed in their previous labor. However, the rest of the research is much more encouraging.

In one Californian study from 2015, 54% of women with no prior vaginal birth and a prior cesarean during pushing stage went on to have a VBAC. In other words, they were just as likely to have a VBAC as not.

Similarly, a Danish study found a 59% VBAC rate in women whose cesareans occurred at 9-10 cm of dilation (9 cm often represents a fully dilated woman with a cervical lip, likely due to fetal malposition). Again, more than half had a VBAC and avoided the risks of additional surgery.

But some studies have results even better than that. In a New York study, 74.5% of women with prior pushing-stage cesareans went on to have a VBAC, some of them with forceps help, which suggests that fetal malpositions were an issue for quite a few.

Echoing those numbers is a Canadian study that found a 75% VBAC rate in those with a prior second stage dystocia cesarean. A very small, older Irish study found a 73% VBAC rate in those with a prior cesarean in the second stage.

Similarly, an older Dutch study found an 80% VBAC rate in those with a prior Arrest of Descent cesarean. This echoes our current Fox 2018 study that found an 84% VBAC rate after prior Arrest of Descent.

In summary, the majority of the research clearly supports the idea that women with a prior cesarean that occurred after full dilation and pushing can be offered a "trial of labor after cesarean" and will have a quite reasonable chance for a VBAC.

In the end, the decision whether to go for a VBAC is the mother's, but she should be reassured that she is just as likely to have a VBAC as not, and in many practices, especially with proactive care regarding fetal position, her chances are even better.

The Importance of Fetal Position

So what causes Arrest of Descent? Why does it happen in some births but not others in the same mother? The answer is usually fetal position.

In Arrest of Descent/CPD cesareans, the problem is usually the BABY'S POSITION, not the mother's pelvis.

If the baby is not well-positioned, labor tends to be slow and extra painful. It often slows or stalls between 4-7 cm of dilation. Often the mother eventually dilates fully but there is little or no progress during pushing. Fetal distress may occur.

Some providers become impatient and intervene with procedures (like breaking the waters) which may do more harm than good. Frequently, they are too quick to move to surgery when more patience might see the position resolve or the baby be born just fine in the "less-optimal" position. Recent research suggests that more than three-fourths of women with prolonged pushing stages (more than 3 hours) will deliver vaginally if just given a little more time.

What kind of fetal positions can cause problems? Read here for illustrations and specifics of the different fetal positions. The Spinning Babies website also has many helpful articles and illustrations on fetal position and how to help create maximum room in the pelvis. In the meantime, below is a brief introduction of the most common fetal malpositions.

Keep in mind that Presentation refers to which part of the baby is presenting first, and Position refers to how the baby is oriented in the mother's body in a head-down position. Also keep in mind that when describing fetal position, obstetric texts reference the back of the baby's head (the occiput) and which way the occiput is oriented in relationship to the mother. Most laypeople find it easier to understand by thinking of which way the baby is looking, so I use both in my descriptions.

Both the Spinning Babies website and The Labor Progress Handbook by Penny Simkin et al. have many ideas for various ways to help malpositioned babies resolve their position, and for creating more space in the pelvis. We will discuss this further in future posts.

Occiput Anterior (Easiest for Birth)


Occiput Anterior or OA
The easiest fetal position for labor and birth is usually Occiput Anterior. This is abbreviated OA and means the baby is head-down with the back of the baby's head against the mother's front; in other words, the baby is looking towards the mother's back. This position is considered the norm and the vast majority of babies will be born in this position.

Direct OA is when the baby is looking directly back at the mother's sacrum. LOA is when the baby is mostly facing the mother's back but his back is a bit towards the left side; ROA is the same but a bit towards the right side.

Ideally, the baby's chin is tipped towards its chest so the smallest possible diameter of its head presents. If the baby's head is not well-flexed, the presenting diameter is a bit larger. If the baby's head is tipped to one side or the other, it can be even larger. More on that below.

Occiput Posterior 


Illustration by Gail Tully, Spinning Babies
One of the most common fetal positions that can cause problems during labor is the Occiput Posterior position. This is abbreviated OP; the back of baby's head is against your back and baby is looking at your tummy. If the baby is directly facing your back, that's direct OP; if it's a little to the right or left, then that's ROP or LOP.

Although many babies enter labor in less-ideal positions like OP, only about 5% stay posterior all through labor and deliver that way. Babies that come out in the OP position are sometimes called "Stargazers" or "Sunny Side Up."

By itself, an OP position does not have to mean a cesarean, since most OP babies turn during labor and become OA before birth. The labor may be a little longer and more painful but it often proceeds just fine with a little patience. However, babies that are persistently posterior all the way through labor and birth have a high rate of problems.

Research clearly shows that persistent posterior babies have higher rates of cesareans for CPD or Arrest of Descent. This is because the presenting head diameter of a baby in OP position is larger than the baby in an OA position. In addition, the back of the baby's head is against the mother's back and that makes for a more painful labor, with lots of back labor and a slower dilation. This in turn often means lots of interventions from care providers that may make the situation worse, like breaking the waters, which takes away the cushion for baby to turn more easily and may lead to fetal distress.

However, OP babies do not always end with cesareans. With time and patience, an OP baby with a flexed head (chin to chest) can often be born vaginally. Alternatively, a vaginal birth may be possible if the care provider is patient and allows extra time for the baby's head to mold enough to descend into the pelvis. When it hits the pelvic floor, it often then rotates from OP to OA on the perineum and may be born quickly. Often an OP baby can be helped to rotate to OA through manual rotation, an instrumental delivery, or maternal postural changes like the all-fours position.

But because of the impatience of many providers, the fetal distress that can occur, and the extra-painful, longer labors associated with OP babies, many persistent OP babies end up being born by cesarean.

Deflexed Heads

If a baby's head is deflexed (not chin to chest), this can cause problems as well. A deflexed head makes the baby's presenting head diameter larger. This means the baby may not fit through very well, or the baby needs extra time for its head to mold enough to get through. OA babies with mildly deflexed heads experience longer labors, but with a little patience, are usually able to be born vaginally.

However, significant problems can occur if deflexion is extreme. Extreme examples of deflexed heads include a brow (forehead first) or face (face-first) presentation. Although vaginal births of brow and face presentations have been documented, most often they end in cesarean these days unless the baby's position can be resolved. Fortunately, brow and face presentations are quite rare.

Deflexed babies in an OP position are fairly common and result in many long, difficult labors. OP babies already start out with a larger presenting head diameter; when they also have deflexed heads (known as a "military" position), this makes the head diameter even larger. Big OP babies often have deflexed heads, making their head diameters even larger. These babies often have extremely long and hard labors, and many end in cesareans. Turn the baby around and/or tip its chin towards its chest so that the head is flexed and the baby would likely fit much better; many cesareans could be avoided.

Occiput Transverse/Transverse Arrest

Occiput Transverse, which can result
in Transverse Arrest
When a baby's head is directly sideways, facing the hip, this is called Occiput Transverse or OTOften OT positions are able to resolve to OA, but sometimes they do not and result in a vacuum extraction, forceps delivery, or cesarean.

OT often occurs when the baby was posterior earlier in labor, tries to rotate to anterior, and gets stuck in the process of turning. Sometimes it is iatrogenic (caused by the provider). If labor is slow, the care provider may break the mother's waters in an effort to speed up labor. This removes the buoyant cushion that can make it easier for the baby to finish its turn and the baby may end up "stuck" in this position. This is called "Transverse Arrest." A fair amount of cesareans are caused by transverse arrest.

Compound Presentation

A nuchal hand presenting alongside the head
Babies who have their hands up by their faces (a "nuchal hand" or sometimes a nuchal elbow/arm) can present another challenge.

The baby is basically OA and in a great position for birth, but the hand or arm beside the head causes larger-than-average presenting parts that must fit through at the same time. If the care provider can get the baby to pull back its arm/hand near birth, the baby is likely to then be born quickly. If the arm/hand remains by the baby's head, pushing is likely to be slow, painful, and difficult. Usually babies with nuchal hands can be born vaginally, but there may be quite a bit of tearing and damage to the mother. If the provider is not patient during a slow pushing stage with a nuchal hand/arm, it may result in a cesarean.

Asynclitic Heads

Asynclitic baby in OA position

Similarly, babies who have their heads tipped to the side instead of straight ("asynclitic") also have difficulty fitting. Instead of the top of the head presenting first, their parietal bone (bony side of head) presents first. The tipped head causes a larger than average head diameter that doesn't fit as easily.

Many asynclitic babies will correct the tilt of their heads if the mother's waters are kept intact and she is able to be mobile in labor. Asymmetric birth positions may help correct the tilt. Once the tilt is corrected, the baby is often born fairly quickly.

If the baby is not able to correct the tilt of its head on its own, then the care provider may be able to help through the use of a vacuum extractor or forceps. Sometimes the tilt of the head goes undiscovered or is not able to be resolved during labor; these babies often are born by cesarean.

Summary

Unfortunately, many women with a prior cesarean for CPD or Arrest of Descent are discouraged from even trying to have a VBAC. They may be told they have little chance at a VBAC and they should just schedule a planned repeat cesarean rather than risk another cesarean during labor. One woman was told:
You've already proven you can't get a baby out of your pelvis.
Obviously, that OB believed that the pelvis itself was the issue, not the baby's position, but the recent Arrest of Descent study suggests it is likely not true.

This kind of misleading "guidance" from care providers is not evidence-based. Most women with a prior CPD or Arrest of Descent cesarean who go through with labor actually have a reasonable chance at a VBAC, as this woman found:
The OB that did my c-section told me that my pelvis was small and also tilted and that because of that, a vaginal birth wouldn't be possible. Well, I...went for a VBAC anyway and it's a good thing I did because I had a wonderful amazing and natural VBAC with my next baby. And she came out in about 4 pushes. It was so easy! I had my second VBAC with my son a year ago and it went perfectly as well!
Here is a link to the story of another case where a woman who had a cesarean was told that her pelvis was too small to birth a baby and to forget about a VBAC. She went on to birth a 9 lb. baby ─ with a nuchal hand ─ as a VBAC. The Birth Without Fear blog has an awesome picture of it in their birth stories section.

That's not to say that CPD is never real. Sometimes it is. Although most cases of "CPD" are actually situational (caused by a malposition), sometimes there are rare cases of true CPD. These are usually a result of significant malnourishment in childhood, severe scoliosis, a history of rickets, or a history of a bad fall or accident where the pelvis was damaged. And sometimes, women don't have any of that in their background, really do try everything, and still end up with a cesarean because the baby just didn't fit. It does happen and it's important to acknowledge that.

But far too often, women who have had a cesarean after not being able to push out a baby are told that their pelvises are too small or defective, and they'll never be able to push out a baby. This is not true. Many women with this history can have a vaginal birth, if given an adequate chance to do so. Anecdotally, many women who have been told this benefit from having a good chiropractor evaluate their back and pelvis to help maximize the space in it and get it well-aligned. See my story below.

Women with a history of cesareans for Arrest of Descent or CPD should be offered the chance at a VBAC if they want it. Chances are good they will have one. There are never any guarantees, but research clearly shows that trying for a VBAC is a very reasonable choice in this group and should not be discouraged.

My Story

Again, many women have had cesareans for arrest of descent and yet gone on to have a VBAC. Conventional wisdom is that you need a smaller baby to get a VBAC, but some women do have VBACs with a baby even bigger than their cesarean baby. Again, fetal position is key.

This includes me. I had my first cesarean after a difficult induced labor. I dilated to 10 cm and pushed for two hours in stirrups, but ended up with a very traumatic cesarean. With my second baby, I had a relatively easy spontaneous labor where I did all the "right" things including position changes but still had FIVE HARD HOURS of pushing with little descent of my deflexed OP baby. I ended up with a second cesarean for CPD.

Both of my babies were big. I was told I had a "marginal" pelvis by my first care provider, and unless I had a smaller baby I would probably not have a vaginal birth. After my second birth, a nurse-midwife told me I probably had a pelvic shape predisposed to posterior babies and my babies would likely always be posterior. After two CPD cesareans at full dilation and after hours of pushing, I was told I was extremely unlikely to have a VBAC. The "VBAC Calculator" gave around a 20% chance of having a VBAC if I tried again.

All these declarations were wrong in the end but it was difficult to have faith. In my third pregnancy, I wavered between choosing to labor again or just going straight to a repeat cesarean. The baby was consistently posterior again all through pregnancy and I had no desire to go through a long hard labor only to end up with another cesarean ─ but neither did I want to go through another surgical recovery. I was also worried about the increase the risk of placental issues from another cesarean if I decided to have another baby in the future.

Near the end of my third pregnancy, I found a chiropractor who did a lot of work on my pelvis, including the Webster Technique and releasing the round ligaments that attach to the uterus. She felt my history of car accidents was highly relevant to the malpositions going on. According to her, the significant back and pubic pain I was having indicated "in utero constraint" that was making it hard for my babies to be in the easiest position for labor. The chiropractic adjustments eased a lot of my discomfort and the baby moved pretty quickly into a more optimal OA position for the first time in three pregnancies!

I went on to have a VBAC after 2 cesareans (VBA2C), something many providers would have told me would be extremely unlikely with my history and risk factors (short, old, "morbidly obese," big babies, two prior CPD cesareans, no prior vaginal births). Instead of pushing for 2 hours or for 5 hours as I did with my first two children, I pushed for 12 minutes with that baby. The doctor didn't even make it to the birth.

And it wasn't just a lucky fluke. Several years later, I had another VBA2C, this time with a baby that was a pound larger than either of my cesarean babies. I only pushed for 24 minutes with that baby.

Afterwards I asked my midwife to evaluate my pelvis and tell me honestly if it was truly marginal or not. She examined me and said it absolutely was not. Either the prior evaluation was wrong or chiropractic care really did create more space in my pelvis ─ or maybe a little of both. I do feel that the chiropractic care was integral to my VBACs, given that I never had an anterior baby until I had chiropractic care.

Remember, each labor and birth is unique and previous problems do not necessarily happen again.

Even a history of more than one Arrest of Descent or CPD cesarean does not mean it will continue to happen, especially if the mother is very proactive about fetal position. I had a history of TWO cesareans for Arrest of Descent and still went on to have two VBACs.

I have known women who have had VBACs after 1, 2, and even 3 prior CPD cesareans, including full dilation and pushing for hours each time with no vaginal birth. Yet they still eventually had a VBAC. The International Cesarean Awareness Network (ICAN) has a number of stories of women who have had a prior cesarean (or more) for CPD or Arrest of Descent and yet went on to have a VBAC. You can see some of them in their "Question CPD" video below.

There are never any guarantees, of course, and there are important risks to consider with both VBAC and an Elective Repeat Cesarean. However, if you choose to labor, your VBAC chances are good, anywhere between 50-80% based on the research. Don't let care providers convince you out of trying for a VBAC based on a past history of CPD or Arrest of Descent. In the end, it's your decision.



April is Cesarean Awareness Month. For more information on cesareans and VBACs, see the International Cesarean Awareness Network. 


References

J Matern Fetal Neonatal Med. 2018 Feb 27:1-5. doi: 10.1080/14767058.2018.1443069. [Epub ahead of print] Vaginal birth after a cesarean delivery for arrest of descent. Fox NS, Namath AG, Ali M, Naqvi M, Gupta S, Rebarber A. PMID: 29455594
...This was a retrospective cohort study of all patients delivered by a single MFM practice from 2005 to 2017 with a singleton pregnancy and one prior CD for arrest of descent. We estimated the rate and associated risk factors for successful VBAC. RESULTS: We included 208 patients with one prior CD for arrest of descent, 100 (48.1%) of whom attempted a trial of labor after cesarean (TOLAC) with a VBAC success rate [of] 84/100 (84%, 95% CI 76-90%). Among the women who attempted TOLAC, women with a prior vaginal delivery >24 weeks' had a significantly higher VBAC success rate (91.8% versus 71.8%, p = .01). Maternal age, body mass index, estimated fetal weight, induction of labor, and cervical dilation were not associated with a higher VBAC success rate. CONCLUSIONS: For women with a prior CD for arrest of descent, VBAC success rates are high. This suggests that arrest of descent is mostly dependent on factors unique to each pregnancy and not due to an inadequate pelvis or recurring conditions. Women with a prior CD for arrest of descent should not be discouraged from attempting TOLAC in a subsequent pregnancy due to concerns about the likelihood of success.
J Matern Fetal Neonatal Med. 2017 Feb;30(4):461-465. Epub 2016 May 5. Prolonged second stage in nulliparous with epidurals: a systematic review. Gimovsky AC, Guarente J, Berghella V. PMID: 27050812
...A systematic review of the literature was performed... for case series evaluating the morbidities of prolonged second stage of labor. Search terms used were "prolonged", "second stage", and "labor". Prolonged second stage was defined as three hours or more. Retrospective case series of prolonged second stage in nulliparous women with epidurals were identified. The primary outcome was the incidence of cesarean delivery. RESULTS: Two retrospective series with 5350 nulliparous women with prolonged second stage were identified. 76.3% (4 081/5 350) had an epidural. Of all nulliparous women with an epidural, 11.5% (4 081/35 469) had prolonged second stage. Cesarean Delivery occurred in 19.8% of these cases (782/4 081), while 80.2% had a vaginal delivery. CONCLUSIONS: Over three quarters of nulliparous women with epidural diagnosed with a prolonged second stage deliver vaginally.
VBAC After CPD Diagnosis

J Obstet Gynaecol Can. 2003 Apr;25(4):275-86. Vaginal birth after Caesarean section: review of antenatal predictors of success. Brill Y, Windrim R. PMID: 12679819
"...Even with a history of CPD, two-thirds of women will have successful VBAC, though rates decrease with increasing numbers of prior CS...There are few absolute contraindications to attempted VBAC. Attempted VBAC will be successful in the majority of attempted cases."
Obstetrics and Gynecology. February 1989. 73(2):161-5. Twice A Cesarean, Always a Cesarean? Phelan, JP et al.  PMID: 2911420
[My summary of highlights from the full text] 501 women with 2 or more previous cesareans had a TOL, and 69% had a VBAC overall. Women who had had at least one previous cesarean for CPD had a 64% VBAC rate. Those who had had 2 successive labors both ending in c/s for CPD still had a 56% VBAC rate. In other words, even those women with a previous 'failed' trial of labor had a better chance of a VBAC than another cesarean in labor.
Other Studies on Arrest of Descent or Similar Definitions
  • Am J Obstet Gynecol. 2015 Dec;213(6):861.e1-5. doi: 10.1016/j.ajog.2015.08.064. Epub 2015 Sep 6. Effect of stage of initial labor dystocia on vaginal birth after cesarean success. Lewkowitz AK, Nakagawa S, Thiet MP, Rosenstein MG. PMID: 26348381
  • Acta Obstet Gynecol Scand. 2013 Feb;92(2):193-7. doi: 10.1111/aogs.12023. Epub 2012 Nov 5. Cervical dilation at the time of cesarean section for dystocia -- effect on subsequent trial of labor. Abildgaard H, Ingerslev MD, Nickelsen C, Secher NJ. PMID: 23025257
  • Obstet Gynecol. 2001 Oct;98(4):652-5. Should we allow a trial of labor after a previous cesarean for dystocia in the second stage of labor? Bujold E, Gauthier RJ. PMID: 11576583
  • Obstet Gynecol. 2000 Apr;95(4): S38. https://doi.org/10.1016/S0029-7844(00)00660-8 Obstetrics Prognostic indicators for successful vaginal birth after cesarean delivery. Marshak J, Cooperman BS, Fried WB, Shi, Quihu. Available here.
  • Br J Obstet Gynaecol. 1998 Oct;105(10):1079-81. Vaginal delivery after previous caesarean section for failure of second stage of labour. Jongen VH, Halfwerk MG, Brouwer WK. PMID: 9800930
  • Obstet Gynecol. 1998 Nov;92(5):799-803. First delivery after cesarean delivery for strictly defined cephalopelvic disproportion. Impey L, O'Herlihy C. PMID: 9794672
  • Obstet Gynecol. 1997 Apr;89(4):591-3. Correlation between maximum cervical dilatation at cesarean delivery and subsequent vaginal birth after cesarean delivery. Hoskins IA, Gomez JL. PMID: 9083318

Saturday, March 24, 2018

Timing of Elective Cesareans in High BMI Women


Doctors do far too many cesareans in high BMI women, especially planned "elective" cesareans without labor. Many of these cesareans are unnecessary and place women of size and their babies at risk. Research shows that about one-third or more of all cesareans done on high BMI women are planned, pre-labor cesareans done on moms who were never even given a chance to labor.

But sometimes cesareans are truly needed, even a planned, non-labor cesarean. And sometimes an elective repeat cesarean is chosen by women. When a planned cesarean happens, it's important not to do it sooner than absolutely necessary.

Labor helps babies prepare for breathing on their own. When a cesarean is done without labor, the baby often has more difficulty establishing breathing on its own. The earlier the cesarean is done, the higher the risk for breathing problems. Therefore, most obstetric guidelines now suggest not doing an elective cesarean before 39 weeks. If a cesarean is medically needed before then, then corticosteroids are usually used to mature the fetal lungs for a while before the cesarean is done.

Recent research on the CDC database now suggests that the 39 week benchmark for planned cesareans is even more important in "obese" women. 

The babies of high BMI women in the study were particularly prone to the need for assisted ventilation (help breathing) and treatment in the Neonatal Intensive Care Unit (NICU). A dose-dependent relationship was seen between BMI and need for assisted ventilation, and this was not modified by use of corticosteroids.

One underappreciated reason for this is that many women of size have longer menstrual cycles than average-sized women. Instead of 28 days, many have menstrual cycles of 35 days or longer. That means that when their babies are delivered at what is thought to be 39 weeks, the babies are really only 38 weeks (or even younger). As a result, their lungs are less mature and less ready to function on their own. No wonder they needed more ventilation and more NICU time!

To improve outcomes in obese women and their babies, care providers should seek to adjust women's due dates to reflect the length of their menstrual cycles, or to have an extremely accurate dating ultrasound early in the pregnancy. And unless there is a critical need to deliver earlier, planned elective cesareans should be held off until between 39 or preferably 40 weeks, especially for those with longer cycles.

It's important to keep pushing doctors to do fewer planned elective non-labor cesareans in obese women; far too many are being done these days. They should be saved for truly necessary situations. But when a planned non-labor cesarean is done, it is critical not to schedule it too soon in order to lessen the risk of breathing complications in the baby.

More attention needs to be paid to ensuring accurate pregnancy dating in women of size. This can be done either by adjusting the due date to reflect the woman's cycle length, or by doing a dating ultrasound early in pregnancy (first trimester), or a combination of both.



References

J Perinat Med. 2018 Mar 15. pii: /j/jpme.ahead-of-print/jpm-2017-0384/jpm-2017-0384.xml. doi: 10.1515/jpm-2017-0384. [Epub ahead of print] Effect of pre-pregnancy body mass index on respiratory-related neonatal outcomes in women undergoing elective cesarean prior to 39 weeks. Vincent S, Czuzoj-Shulman N, Spence AR, Abenhaim HA. PMID: 29543593
OBJECTIVE: To examine the association between pre-pregnancy body mass index (BMI) and neonatal respiratory-related outcomes among women who underwent an elective cesarean section (CS). METHODS: A retrospective cohort study was conducted using the Centers for Disease Control and Prevention (CDC)'s 2009-2013 period linked birth/infant death dataset. Women who had elective CSs at term were categorized by their pre-pregnancy BMI as normal, overweight, obese or morbidly obese...A dose-dependent relationship between maternal pre-pregnancy BMI and assisted ventilation was seen. Furthermore, infants born to morbidly obese women were at significantly increased risk for assisted ventilation over 6 h (OR 1.24, 95% CI 1.15-1.35) and admission to intensive care units (OR 1.17, 95% CI 1.13-1.21). Infant mortality rates were 4.2/1000 births for normal weight women, and 5.5/1000 births among the morbidly obese group (OR 1.43, 95% CI 1.25-1.64). Risk for adverse outcomes was increased with elective SC performed at earlier gestational age, and this effect was not modified by use of corticosteroids. CONCLUSION: Overweight and obese women are at particularly greater risk of adverse newborn outcomes when elective CSs are done before 39 weeks. In these women, elective CSs should be delayed until 39 weeks, as corticosteroid use did not eliminate this association.
Obstet Gynecol. 2017 Nov;130(5):994-1000. doi: 10.1097/AOG.0000000000002257. Trial of Labor Compared With Cesarean Delivery in Superobese Women. Grasch JL, Thompson JL, Newton JM, Zhai AW, Osmundson SS. PMID: 29016512
We conducted a retrospective cohort study of all women with body mass indexes (BMIs) at delivery of 50 or greater delivering a live fetus at 34 weeks of gestation of greater between January 1, 2008, and December 31, 2015...RESULTS: There were 344 women with BMIs of 50 or greater who met eligibility criteria, of whom 201 (58%) labored and 143 (42%) underwent planned cesarean delivery...CONCLUSION: Despite high rates of cesarean delivery in women with superobesity, labor is associated with lower composite maternal and neonatal morbidity. Severe maternal morbidity may be higher in women who require a cesarean delivery after labor.
Epidemiology. 2002 Nov;13(6):668-74. Influence of medical conditions and lifestyle factors on the menstrual cycle. Rowland AS, Baird DD, Long S, Wegienka G, Harlow SD, Alavanja M, Sandler DP. PMID: 12410008
...We analyzed cross-sectional data collected from 3941 premenopausal women from Iowa or North Carolina participating in the Agricultural Health Study between 1994 and 1996. Eligible women were age 21-40, not taking oral contraceptives, and not currently pregnant or breast feeding. We examined four menstrual cycle patterns: short cycles (24 days or less), long cycles (36 days or more), irregular cycles, and intermenstrual bleeding. RESULTS: Long and irregular cycles were less common with advancing age and more common with menarche after age 14, with depression, and with increasing body mass index. The adjusted odds of long cycles increased with increasing body mass index, reaching 5.4 (95% confidence interval [CI] = 2.1-13.7) among women with body mass indexes of 35 or higher compared with the reference category (body mass index of 22-23)....

Sunday, December 10, 2017

Preventing Cesarean Complications in High BMI Women


In our last post, we discussed the best evidence-based practices for lessening the risk for infections and other wound complications after cesarean in women of all sizes. This is vital because 1 in 3 women in the United States has a cesarean these days, and many will have only cesareans because of lack of support for Vaginal Birth After Cesarean (VBAC). That's a lot of cesareans and a lot of chances for complications to happen.

However, if there are a lot of cesareans in women in general, there are even more in high BMI women, raising the potential for post-cesarean complications even further. 

The rate of cesareans in "obese" women is astronomically high, with rates in many studies hovering between 50-60% in high BMI women, and reaching as high as 70-80% at times. This is recipe for disaster because surgery is more risky in general in high BMI women and they have more wound complications afterwards.

Wound complications rise as BMI rises
Graph from Conner 2014
Research shows the risk for infection after cesarean in obese women is higher, and that infection risk rises as BMI increases. Surgical Site Infections (SSIs) are a real concern in very high BMI patients.

This is because fat layers have less vascularization and poorer oxygenation, making the healing process more difficult. Women of size also tend to have a higher risk for collections of fluid or blood in the wound (seromas and hematomas), which predispose to the wound coming apart and having trouble healing. Furthermore, the risk for blood clots after cesareans is increased in high BMI women as well, and blood clots can be deadly. So the implications of a high cesarean rate in women of size are very important.

The best way to lower cesarean morbidity in obese women is to lower the overall rate of unnecessary cesareans in this group. However, when cesareans are necessary, there are things that caregivers can do to decrease the risk for complications. These include:
  • Transverse incisions instead of vertical incisions 
  • Sutures instead of staples 
  • Increased or weight-based dosing of antibiotics 
  • Extended spectrum or extended regimen of antibiotics 
  • Thromboprophylaxis (blood clot prevention)
  • Closure of the subcutaneous space 
  • Avoidance of surgical drains 
  • Negative pressure wound therapy (possibly)
Transverse (Side-to-Side) Incision

Many providers have erroneously been taught that a vertical (up-and-down) incision will be safer and less prone to infection than a transverse (side-to-side) incision in obese women, especially as BMI goes up. They were taught that an overhanging belly (panniculus) would predispose to infection because of the potentially hot, moist environment under it.

For years this was an unquestioned belief, until a 2005 study found that there was TWELVE TIMES the risk for wound complications with a vertical incision compared to a transverse one in obese women.

A number of studies since then have also found increased wound complications and blood loss in vertical incisions in obese women and equivalent or better outcomes with transverse incisions.

Some doctors like to cite a 2014 study that supposedly found better results with a vertical incision. However, a further scrutiny of the data found that the researchers used the wrong variable in their analysis. When re-analyzed correctly, they found that a transverse incision was indeed superior. A retraction of the original study was made, but many doctors are unaware of it.

Some doctors use transverse incisions on women with moderate obesity but feel that vertical incisions are necessary on women with very high BMIs. However, one study on "super obese" women (BMI 50+) concluded that transverse incisions were preferable even in this group for many reasons:
Transverse abdominal incisions are less painful and allow for earlier mobilization and decreased pulmonary complications. Furthermore, vertical abdominal incisions were associated with vertical hysterotomy [uterine incisions] in our study, usually a result of inadequate access to the lower uterine segment. When the incision extends into the contractile portion of the uterus, a vertical hysterotomy has a profound impact on future pregnancy. Therefore, it is important to incorporate practices, like transverse abdominal incisions, that facilitate low uterine incisions.
At this time, most OBs have switched to transverse incisions in obese women, even very obese women. Although vertical incisions are sometimes indicated in rare cases or in true emergencies, it is usually not necessary to use a vertical incision even in very obese women. Low transverse incisions have been used successfully even in women of 400-500 pounds without poor outcomes. And higher transverse incisions (Joel-Cohen incisions done slightly higher, or transverse incisions near the umbilical in rare cases) are also an option if necessary.

However, some doctors stubbornly cling to a "vertical is better" policy, especially as BMI increases. Research shows that vertical/classical incisions are still more common in high BMI women than those with an average BMI.

Although most OBs today use the transverse incision on women of size, up to 20% prefer a vertical incision in women with a BMI over 40, despite its strong association with more wound problems. Using mostly transverse incisions is one obvious way to improve outcomes in high BMI women but one which some OBs are stubbornly slow to adopt.
Sutures Instead of Staples

Most OBs still use staples to close the skin incision after a cesarean. The advantage is that staples are completed more quickly, so the woman is not exposed as long to outside germs, which in theory may decrease the risk for infection. Staples are also relatively easy to apply; much easier than doing sutures.

Staples are used even more commonly in high BMI women. One large hospital in a major urban center recently documented that 63% of obese women in their institution received staples, while only 32.5% received subcuticular sutures.

If staples are used in obese women, some research indicates that it may be advantageous to leave them in slightly longer before removal. However, while there was a distinct trend towards less complications in the delayed removal group, the difference did not rise to statistical significance. Optimal timing of the removal of staples in obese women is a question still to be answered.

But the best choice for skin closure in women of size is probably subcutaneous sutures.

meta-analysis in women of all sizes found that sutures lowered the rate of wound complications considerably, even when obesity was controlled for. One hospital in Alabama found that staples was associated with more than five times the risk for wound disruption. Furthermore, a hospital in San Diego was able to lower its wound complication rate from 10.1% to 4.5% by making an institutional switch from staples to sutures.

Sutures do take longer to do, but the difference is only 5-10 minutes. Taking longer might raise the risk for infection slightly, but using sutures lowers the risk for infection far more than a slightly longer surgery raises it. This is a very reasonable trade-off.

Similarly, new research confirms that using sutures instead of staples lowers the risk for wound complications in obese women. One recent study found a 22% rate of wound complications in obese women who were closed with staples, versus a 9.7% rate in those closed with sutures. That's a striking difference.

Despite this, doctors are LESS LIKELY to use sutures as BMI goes up. It is not clear why this is true, but probably many OBs don't want to take the time and effort to do subcuticular sutures on very fat women (which is harder), and they don't feel the same need to make the scar look seamless and "pretty" for very large women.

But it bears repeating that to improve outcomes in high-BMI women with cesareans, sutures should be used more often, even as BMI increases. It should not be about what saves the surgeon the most time, the technical difficulty of suturing adipose tissue, or about whether a larger woman "needs" to have a beautiful scar; it should be about what decreases the risk for wound complications, and sutures clearly do that best.

Staples vs. sutures is one area that needs a major change of practice, both among women of average size and among high BMI women. Yet many surgeons greatly resist changing this practice.

Weight-Based Dosing of Antibiotics

We have written before about the importance of weight-based dosing for certain types of antibiotics. Not every type of antibiotic needs weight-based dosing, but some do. It all depends on their mechanism of action.

The class of antibiotics called cephalosporins is one of the most commonly used antibiotics before a cesarean and many other surgical procedures. It is chosen because it is generally well-tolerated, is effective against skin-borne pathogens, and has a low incidence of allergic reactions. Cefazolin is the most commonly used cephalosporin in cesareans.

The right dosage of antibiotics is very important. Too high a dose and serious side effects like severe diarrhea or organ damage can occur. Most of the good bacteria in your gut can be obliterated, leaving the bad antibiotic-resistant bacteria like C. difficile to take over. But too low a dose and the infection may not be completely wiped out, enabling the bad bacteria to develop resistance, causing a resurgent infection that does not respond to antibiotics. This can cause a prolonged recovery or even death. So finding the right dose is a balance between too much and too little.

Most of the research on dosage of antibiotics has been done on people of average size but applied to people of all sizes. Obese patients were frequently excluded from dosage studies. Only recently have researchers begun asking what the best dosage is for high BMI people, and they still have only limited data to guide them.

Historically, underdosing high BMI people has been a serious problem. Doctors assume that most obese people have impaired liver and kidney function, so they erred on the side of conservative dosing in order to minimize possible side effects and organ damage. But in doing so, they have been exposing obese patients to higher risks of infection and wound issues.

Some pharmacological research is now being done to determine optimal dosing by body weight, but guidelines are sparse and have major gaps in knowledge. Even when optimal dosing guidelines do exist, doctors often do not follow them.

The standard dosage used to be 1g of cefazolin before cesarean for all sizes of women, but now 2g is recommended to improve outcomes in obese women.

Some guidelines and researchers have suggested that very high BMI patients having various types of surgery might need a 3g dose (or more) instead in order to reach the minimum inhibitory concentrations needed to prevent infection.

Research on whether 3g does improve outcomes has been mixed. In non-cesarean surgeries, outcomes do not seem improved by the higher initial dose. However, in cesareans in class III and IV obesity (BMI over 40 and 50) there is some research to suggest improved outcomes, but other research disagrees or is inconclusive.
At this time, most moderately obese women are given 2g of cefazolin and generally do well. Beyond that, more research is needed.

Best guess is that it is probably not necessary to increase dosages beyond 2g in women with BMIs between 30 and 40. However, we need additional research, stratified by BMI, on the optimal dosage for women in class III (BMI 40 or more) and super obesity (BMI 50 or more). This research is urgently needed, but until we have it, it seems sensible to err on the side of 3g when BMI nears or exceeds 50, or to consider the use of additional antibiotics (see below).

Extended Spectrum or Extended Regimen Antibiotics

It may be that improving post-surgical outcomes in high BMI people is about both how much antibiotics they receive initially and whether they receive additional antibiotic agents during or after the surgery. Weight-based dosing and extended antibiotic regimens is something size-acceptance activists have been pushing for for years, but only now is the medical community really starting to take it seriously.

Old standards called for antibiotics to be discontinued after surgery or within 24 hours. New research has shown that a combination of antibiotics and/or the addition of more antibiotics during surgery or post-operatively lowers the risk for infections and other complications in women of all sizes, and particularly in high BMI women.

For example, a multi-center large study on women of all sizes showed that cefazolin plus azithromycin was more effective in reducing post-operative complications. Serious infections were cut in HALF.

It would be interesting for this study to be duplicated in a group of diverse obese women, stratified by BMI. That would tell us whether the addition of azithromycin would be especially helpful in larger women, and at what BMI cutoffs.

One important recent study of obese women having cesareans found that an IV cephalosporin before surgery followed by an oral dose of both a cephalosporin and metronidazole 3x/day for 2 days afterwards decreased infections quite significantly. SSIs were diagnosed in only 6.4% receiving post-operative oral antibiotics, versus in 15.4% of the women receiving a placebo after surgery. That's an impressive decrease for just 2 more days of antibiotics.

An editorial accompanying this study called for more research on whether special subgroups might particularly benefit from post-operative antibiotics. They noted that in the group of obese women whose waters had been broken during labor, the infection rate was strikingly lower in those who received post-op antibiotics vs. those who received a placebo (9.5% vs. 30.2%). The difference was only minimal in the group whose waters were still intact (5% vs. 8.7%). So it may be that we don't need to give all obese women routine post-op antibiotics, but that its use should be prioritized to obese women with extra risk factors for infection.

Unfortunately, there is only very limited research on cesarean antibiotic regimens in obese women, so many protocols are extrapolated from bariatric or gynecologic surgeries. This potentially limits their applicability to obstetric situations but at least offers some guidance in the absence of other data.

During bariatric surgery, for example, one study found that an initial pre-operative 2g dose of cefazolin followed by an additional 1g of cefazolin given by continuous IV dosage during the surgery resulted in better outcomes than other combinations of various antibiotics.

In one gynecological study of obese women receiving a hysterectomy and panniculectomy (removal of extra belly fat and skin, which has a high risk for infection), a regimen of 2g of cefazolin at surgery and then oral ciproflaxin post-operatively resulted in far fewer SSIs (5.9% vs. 27.9%).

So bariatric and gynecologic data and preliminary research in obstetric populations suggest that additional antibiotics after surgery may be helpful in high BMI women, especially those with additional risk factors. But it's very frustrating that more work has not been done on this in high BMI women, given how many cesareans are egregiously being done in this group. How many problems could have been prevented if this research had already been done so providers knew the best practice?

Even the obstetric studies we do have tend to be sub-par. Most have been too small to be really meaningful. Some have focused only on concentrations of cefazolin in the blood at various times in surgery, rather than also including outcome data (how many women developed infections afterwards in the different dosing groups). Concentrations in the blood are an important potential indicator of problems, but what really counts is how this all translates into actual outcomes.

We need more data specifically on antibiotic dosage for CESAREANS in obese women, stratified by BMI, emphasizing actual outcomes, rather than doctors extrapolating dosages from other types of surgery or from blood and tissue concentrations. 

Until we have the data we need to confirm best practices, expert advice and common sense seem to suggest using at least 2g dosages in women above a BMI of 30-35, and to consider using 3g for women with a BMI over 50 or extra risk factors for infections like broken waters, diabetes, heavy blood loss, etc. Alternatively, adding extra antibiotics (either during surgery or post-operatively) should be considered in these women. As one guide summarizes:
Extended-spectrum antibiotic prophylaxis, with an agent such as azithromycin, may be beneficial in patients at higher risk of postcesarean infectious morbidity, such as those who are obese or diabetic.
Thromboprophylaxis Questions

Obesity increases the risk for blood clots in general, and so does pregnancy. Having cesarean surgery further increases the risk for blood clots. Therefore, obese pregnant women subjected to a cesarean are at particular risk for blood clots. Preventing this is an important part of improving cesarean outcomes in women of size.

Although the absolute risk of getting a blood clot  in this group is relatively small, the potential for great harm or death is very high if it does occur. Blood clots can travel to the lungs (pulmonary embolism), to the brain (stroke), or to the heart (heart attack), and can be fatal.

Sometimes caregivers don't take the possibility of blood clots seriously enough in obese women; there has been more than one story of an obese woman complaining of shortness of breath after a cesarean, only to have it shrugged off by a doctor as being caused by being "overweight and out of shape." Missing a pulmonary embolism can be deadly, so caregivers must take symptoms seriously and not blame obesity alone for symptoms.

On the other hand, some in the obstetric community overreact to the possibility of blood clots in high BMI women and prescribe blood thinners for every high BMI woman, even when there are no other risk factors and she gives birth vaginally.

Too little blood thinner when needed increases the risk for deadly blood clots. Too much blood thinner can result in hemorrhage and wound complications. Finding the right balance is critical.

The first question about thromboprophylaxis in obese women is whether these drugs should be routinely administered to all obese women to prevent blood clots, or used only when additional risk factors necessitate them.

At this point, there is little research on the topic. Standard protocol for preventing blood clots is getting the patient walking as soon as possible after surgery, and using pneumatic mechanical devices or compression stockings to stimulate blood flow while in bed. These approaches work very well to prevent blood clots in most cesarean mothers, including obese women, without blood thinners. The standard of care in the U.S. is to use blood thinners only when indicated by extra risk factors.

On the other hand, the NICE guidelines in the U.K. suggest using blood thinners prophylactically for 7-10 days with ALL obese patients with a BMI of 40 or more, regardless of how they gave birth. However, this recommendation was developed by the Royal College of Obstetricians and Gynaecologists based on "consensus," not on data that shows improved outcome with routine thromboprophylaxis in all obese women. We need recommendations based on actual data, not guesses and fears.

Some research suggests increased wound complications in obese women who receive thromboprophylaxis. Further research is needed to determine the benefits and harms of routine use of thromboprophylaxis in obese cesarean patients before such a policy is implemented widely.

It's doubtful that thromboprophylactic drugs need to be used routinely in every high-BMI woman. However, routine blood thinners probably are a wise precaution in those who are particularly at risk for blood clots, like smokers, those with a family history suggestive of clotting disorders, those who cannot move around freely, and perhaps in super-obese patients.

Another important question is thromboprophylaxis dosage. If weight-based dosing of antibiotics is important for improving outcomes in women of size, what about weight-based dosing for blood thinners?

As with antibiotics, most thromboprophylaxis research has not included adequate numbers of obese subjects so optimal dosing remains based on guesswork. The type of blood thinner being used matters; direct oral anticoagulants like Eliquis (apixoban) do not need weight-based dosing, whereas unfractionated heparin and low molecular weight heparin (the drugs used in pregnancy) do benefit from weight-based dosing.

The most commonly used blood thinner after cesareans is a low molecular weight heparin like Lovenox (enoxaparin sodium). Recent research shows that weight-based dosing of products like Lovenox is helpful in preventing blood clots. One study found that 88% of post-cesarean obese women achieved the minimum concentration needed when weight-based dosing was used, but only 14% achieved it when standard dosing was used.

Another study found that weight-based dosing was superior to BMI-category dosing after a cesarean. In other words, dosing by actual weight had better outcomes than generalizing one dosage for all women between a BMI of 40-50, for example. 86% of patients with weight-based dosing had optimal anti-clotting concentrations, compared with only 26% on the BMI-stratified dosing.

Further research on when and how to use thromboprophylactics in high BMI women is needed, but if thromboprophylactics are given, they should be dosed in a way that will be effective for the patient's size, and that means weight-based dosing.

Closure of Subcutaneous Space

When there is a substantial fat layer, there is an increased risk for surgical wounds to re-open. Adipose tissue tends to be poorly vascularized, and this relative lack of blood flow means there is less oxygenation. In addition, leaving a gap in this adipose tissue may predispose the area to seromas (collections of fluid in the wound), which may inhibit wound healing.

So years ago some surgeons began loosely closing the subcutaneous space in an extra layer in the hopes of improving outcomes. What they found was that closing the subcutaneous space didn't make much difference if the adipose layer was small, but it made a very significant difference if the adipose layer was greater than 2 cm.

In one study, closing the subcutaneous layer when it exceeded 2 cm cut the rate of wound complications in obese women by a third.

Experts agree that closing the subcutaneous space lessens the risk for infections, seromas, and wound dehiscence in women of size. It should be standard of care to improve outcomes in high-BMI women, but while it is used by many surgeons, it is not yet used universally.

Avoidance of Surgical Drains

The use of surgical drains (like a Jackson-Pratt drain) to siphon off excess fluid accumulating in the cesarean wound is controversial.

Drains were thought to be necessary to prevent seromas, which then might raise the risk for infection and the wound coming open.

On the other hand, drains leave open a path for infection into the body and may increase the risk for a seroma, not decrease it. Although an occasional study has found drains helpful, more studies have found drains to be of no benefit or even to be harmful.

At this point, most experts recommend against the routine use of surgical drains after a cesarean, even in very obese women.

Negative Pressure Wound Therapy

Another technique that is being investigated to reduce wound complications after cesareans is Negative Pressure Wound Therapy (NPWT). A "Wound Vac" is placed over the incision and then sealed. The negative pressure is thought to help the wound heal faster and cleaner, although not all studies have found it helpful.

Still, some studies have proposed routine use of NPWT in patients at higher risk for infection and wound complications after surgery, which many would interpret to include obese women after cesarean. Whether this is a good idea or not remains to be seen. Certainly some people with established infections are clearly helped by NPWT, so it should absolutely remain a tool in the toolkit for when infections occur. But whether it should be routinely used with all obese patients as a potential prevention measure needs more study.

One recent small study found a trend towards less wound complications and decreased use of pain medications in the negative pressure wound therapy group, and another small study found fewer infections.  However, a meta-analysis of several studies found no real benefit to using negative pressure wound therapy prophylactically in obese women.

More data is needed on its routine use in obese women having cesareans before it can be recommended. However, it is another option that women of size can discuss with their provider for treatment if they do experience a wound infection. Other options that may help heal wound infections include silver-impregnated wound dressings and perhaps medical honey.

Summary

As we discussed in the first post of this series, research is clear that there are many things providers can do to lower a woman's risk for complications after a cesarean, including:
  • Antibiotics administered before skin incision 
  • Adding an additional antibiotic to the standard cephalosporin 
  • Using chlorhexidine-alcohol (Hibiclens) for disinfecting the skin instead of iodine 
  • Using clippers on body hair instead of shaving the area 
  • Removing the placenta through gentle traction instead of by manual removal 
  • Closing the wound with sutures instead of with staples 
Some of these interventions have been adopted quickly and gladly by the obstetric community, while others are still struggling to find widespread acceptance. One recent review of over 1,000 patients found that only one-third of cesarean mothers received all four of the evidence-based bundle recommendations in that study to reduce wound complications. These are extremely basic precautions, and yet two-thirds of women receiving cesareans did not get them. Obviously, there is huge room for improvement here.

Precautions Specific for High BMI Women

There is even more room for improvement in the treatment of high BMI women. We know that these women are more at risk for infections and wound complications after cesarean compared to average-sized women, yet they often do not receive interventions that would lessen their risk.

Here is a best-practice summary of the things that clinicians can do to decrease the risk for infection and wound complications after a cesarean in obese women and an evaluation of how well these practices have been adopted by the obstetric community:
  • Transverse incision instead of a vertical incision - Transverse incisions greatly decrease wound dehiscence and blood loss in obese women, yet doctors still use vertical incisions too often in obese women, especially as BMI goes up. While most OBs use transverse incisions in larger women, too many are still using vertical incisions; this practice must change
  • Sutures instead of staples - Skin closure with sutures decreases the rate of Surgical Site Infections in both average-sized and high BMI women, yet research shows that surgeons are less likely to use sutures with obese women. Hospitals must start promoting sutures for skin closures in all women, but especially in women of size
  • Weight-based dosing of antibiotics - Weight-based dosing of 2g (and possibly 3g for very high BMI women) of a cephalosporin like cefazolin decreases infection rates in obese women. More outcome-based research, stratified by BMI, is needed to determine optimal dosages
  • Extended spectrum/regimen antibiotics  - New research suggests that standard antibiotics plus an extended spectrum antibiotic or post-operative antibiotics improves outcomes in high BMI women, but this is not routine practice yet. More research specific to high BMI women and cesareans is needed to determine the most optimal antibiotic regimens
  • Weight-based dosing of thromboprophylaxis - Mechanical means of lessening the risk for blood clots (compression stockings, pneumatic pumps, early ambulation) should be automatically used with obese women post-operatively. Routine use blood-thinning drugs in all high BMI women needs more research before being implemented. If there are multiple strong risk factors for blood clots, then thromboprophylactic drugs should be strongly considered, using weight-based (not fixed) dosing
  • Closure of the subcutaneous space - Research has been clear for a long time that suturing a subcutaneous tissue depth of 2 cm or more improves outcomes. While many OBs do this, not all do. Closure of the subcutaneous space should be automatic by now for all obese women
  • Avoidance of surgical drains - Current consensus is that surgical drains are not helpful or necessary in obese women and may well worsen outcome. Most OBs no longer use surgical drains in obese women, but a few still do. This practice should stop
  • Negative Pressure Wound Therapy - Research is mixed on NPWT right now. Some research shows benefit, but a meta-analysis of trials in obese women shows no difference in outcomes. More research is needed, but NPWT in obese women is probably only justified in those with infection, or possibly in those at highest risk of infection due to multiple strong risk factors 
Clearly, there are things that clinicians can do to improve outcome among high BMI women who have a cesarean. Sadly, research shows that some of the above steps are actually LESS likely to be used with high-BMI women, especially those in the upper echelons of BMI.

Graph from Connor 2014
Look at the graph. The blue bars show the rate of midline vertical incisions increases greatly as BMI goes up. This may be one reason why the blood loss rates (pink bars) are higher as BMI increases, since vertical incisions result in more blood loss. And the greater the blood loss, the more risk for infection.

The green bars show that the rate of suture closure is quite a bit lower in the obese groups. There is a small increase of suture use in the BMI >50 group compared to the BMI 40-49 group, but the difference is marginal. Taken as a whole, the suture rate is much lower in all of the obese groups compared to the BMI <30 group, despite the fact that we know that sutures would lower the risk for infection in this group.

In other words, the very things that increase wound complications the most (use of staples and use of vertical incisions) is actually increased in obese women! This is unconscionable, especially when we know that obesity is such a strong risk factor for SSIs and wound complications after a cesarean.

It's also important to point out that in the 2017 review referenced above, when all four best practices were used (antibiotics before skin incision, chlorhexidine-alcohol skin prep, closure of subcutaneous layer if ≥2 cm of depth, and subcuticular skin closure with suture), strong risk factors like diabetes, smoking, and obesity were no longer associated with wound complications.

In other words, while obesity is a risk factor for wound problems and infections after cesareans, with evidence-based care, this risk can be greatly decreased.

The difficulty is in getting care providers to routinely follow best practices with high BMI women. Much progress is needed in this area.
The Best Prevention is Fewer Cesareans

When cesareans do occur in high BMI women, it is important to minimize the risk for infection and wound complications. For a long time, practice was based mostly on guesswork rather than on real data. Now we have more data to guide best-practice guidelines, though we still need more.

However, the best way to prevent wound complications and infections is by doing fewer cesareans in this group. 

The cesarean rate is outrageously high in obese women. There are many studies documenting a high c-section rate in obese women, and the cesarean rate has increased more in "morbidly obese" women than in other BMI groups over time.

VBAC is often strongly discouraged in heavier women, leading to a high rate of repeat cesareans. Yet multiple cumulative cesareans carries a particularly high morbidity rate for high BMI women compared to other women.

But care providers are not powerless to lower the c-section rate. Many studies have shown that cesarean rates can be lowered safely when attention is focused on the problem.

Yet not one study has been done to see how to lower the cesarean rate in obese women.

There are studies that speculate about ways to lower the c-section rate in women of size, but I have yet to see a randomized controlled study that tested specific protocols and how they affect outcomes. Without direct evidence, all we can do is speculate about actions likely to lower the cesarean rate in this group.

The most obvious way to improve the c-section rate in obese women would be to lower the rate of planned elective cesareans in this group. Many care providers routinely schedule non-labor cesareans for women with a high BMI, even though research shows this does not improve outcome. In one recent study, one-third of very obese women had primary cesareans without labor. Another recent study found that 42% of women with a BMI >50 were scheduled for planned non-labor cesareans. If some of these women then develop serious wound complications (not to mention the downstream complications of placental issues in future pregnancies), that's a LOT of morbidity resulting from cesareans that are questionable in the first place.

The cesarean rate in women of size who labor could probably be considerably reduced with more physiologic labor management. Many care providers have been taught that a high cesarean rate in labor is inevitable in very fat women, yet rates are actually highly variable in obese women. This suggests that there is room for change.

For example, one study of "super obese" (BMI 50+) women from the U.K. showed HALF the cesarean rate compared to a similar group in Kentucky and other groups in Australia and Canada. The U.K. rate was 30%, vs. the 50-60% cesarean rate of super obese women in other areas. This shows that the cesarean rate in labor could be far less in high BMI women, and is potentially modifiable.

Most very obese women rarely see midwives and this may also be part of why they have high cesarean rates, since hospitals with a high rate of births attended by midwives tend to have lower cesarean rates. Research shows that midwives can safely attend obese birthing women.

Obese women are induced at very high rates, and this may be a strong part of the cesarean rate in this group as well. In addition, obese women are submitted to high rates of interventions during labor compared to other women. More patience during labor, especially in the early phase up to 6 cm of dilation, may be needed in the labors of obese women. Research suggests the cesarean rate in obese women could be lowered considerably with better management and more patience.

Women who have had a cesarean should usually be encouraged to VBAC if they wish it. Even though VBAC rates are modestly lower in obese women and VBAC prediction models are often used to counsel high BMI women away from VBAC, recent research shows that many obese women CAN have a VBAC with good support.

Actions taken in labor may influence the rate of wound complications if a cesarean does occur. Caregivers often push obese women have early placement of epidurals and rupture of membranes for internal fetal monitors, but these may be associated with higher risk for infection and wound complications if the mother ends up with a cesarean. In addition, lowering the number of vaginal exams in labor and keeping the waters intact as long as possible during labor may help lower the risk for infection if a cesarean does become necessary.

There are many possibilities for trying to lower the cesarean rate in obese women, but at this point, no one is even seriously studying how to do so. It is time for that to change.

If doctors truly want to lower the high rate of cesarean wound complications in obese women, the most effective way to do so is to lower the number of cesareans done in this group. Then if a cesarean does become necessary, the hospital should ensure that physicians use evidence-based protocols based on research into women of size. 



References

General References
Obesity and Avoiding Cesarean Wound Complications

Am J Obstet Gynecol. 2017 Jun 8. pii: S0002-9378(17)30734-2. doi: 10.1016/j.ajog.2017.05.070. [Epub ahead of print] Impact of evidence-based interventions on wound complications after cesarean delivery. Temming LA, Raghuraman N, Carter EB, Stout MJ, Rampersad RM, Macones GA, Cahill AG, Tuuli MG. PMID: 28601567
...Risk of wound complications in women who received all 4 evidence-based measures (prophylactic antibiotics within 60 minutes of cesarean delivery and before skin incision, chlorhexidine-alcohol for skin antisepsis with 3 minutes of drying time before incision, closure of subcutaneous layer if ≥2 cm of depth, and subcuticular skin closure with suture) were compared with those women who did not...RESULTS: Of 1082 patients with follow-up data, 349 (32.3%) received all the evidence-based measures, and 733 (67.7%) did not. The risk of wound complications was significantly lower in patients who received all the evidence-based measures compared with those who did not (20.3% vs 28.1%; adjusted relative risk, 0.75; 95% confidence interval, 0.58-0.95)...Other risk factors, which include obesity, smoking, diabetes mellitus, chorioamnionitis, surgical experience, and skin incision type, were not significant among patients who received all of the 4 evidence-based measures....
N Am J Med Sci. 2012 Jan;4(1):13-8. doi: 10.4103/1947-2714.92895. Cesarean section in morbidly obese parturients: practical implications and complications. Machado LS. PMID: 22393542 Full free text can be found here.
...A Medline search was conducted to review the recent relevant articles in english literature on cesarean section in morbidly obese women. The types of incisions and techniques used during cesarean delivery, intra-operative and postpartum complications, anesthetic and logistical issues, maternal morbidity and mortality were reviewed...Low transverse skin incisions and transverse uterine incisions are definitely superior and must be the first option. Closure of the subcutaneous layer is recommended, but the placement of subcutaneous drains remains controversial. Thromboprophylaxis adjusted to body weight and prophylactic antibiotics help in reducing postpartum morbidity....
Best Pract Res Clin Obstet Gynaecol. 2015 Apr;29(3):406-14. doi: 10.1016/j.bpobgyn.2014.08.009. Epub 2014 Oct 16. Obesity and the challenges of caesarean delivery: prevention and management of wound complications. Ayres-de-Campos D. PMID: 25457856
Caesarean section in obese patients is associated with an increased risk of surgical wound complications, including haematoma, seroma, abscess and dehiscence... Appropriate dose of prophylactic antibiotics, closure of the subcutaneous tissue, and avoidance of subcutaneous drains reduce the incidence of wound complications associated with caesarean section in obese patients. For treatment of superficial wound infection associated with dehiscence, there are data from general surgery patients to suggest that the use of vacuum-assisted devices leads to faster healing and that surgical reclosure is preferable to healing by secondary intention, when there are no signs of ongoing infection. There is a need for stronger evidence regarding the prevention and management of wound complications for caesarean section in obese women.
Surg Infect (Larchmt). 2015 Apr;16(2):174-7. doi: 10.1089/sur.2014.145. Epub 2015 Mar 31. A journey to zero: reduction of post-operative cesarean surgical site infections over a five-year period. Hickson E, Harris J, Brett D. PMID: 25826622  Full free text found here.
...A risk-based approach to incision management was developed and implemented for all cesarean deliveries at our institution. A number of incremental interventions for low-risk and high-risk patients including pre-operative skin preparations, standardized pre- and post-operative protocols, post-operative nanocrystalline silver anti-microbial barrier dressings, and incisional negative pressure wound therapy (NPWT) were implemented sequentially over a 5-y period. A systematic clinical chart review of 4,942 patients spanning all cesarean deliveries between 2007-2012 was performed to determine what effects the interventions had on the rate of SSI for cesarean deliveries. RESULTS: The percentage of SSI was reduced from 2.13% (2007) to 0.10% (2012) (p<0.0001)... As a result of the changes in incision management practice, a total of 92 cesarean post-operative SSIs were avoided.... [Kmom note: All women with a BMI over 35 were considered high-risk for SSIs and routinely given the interventions listed.]
Incision Type in Obese Patients

Obstet Gynecol. 2003 Nov;102(5 Pt 1):952-6. Vertical skin incisions and wound complications in the obese parturient. Wall PD, Deucy EE, Glantz JC, Pressman EK. PMID: 14672469
...RESULTS: From 1994 to 2000, 239 women with a BMI greater than 35 undergoing a primary cesarean delivery were identified. The overall incidence of wound complications in this group of severely obese patients was 12.1%. Factors associated with wound complications included vertical skin incisions (odds ratio [OR] 12.4, P < .001) and endometritis (OR 3.4, P = .03)...Our data indicate that a vertical skin incision is associated with a higher rate of wound complications than a transverse incision.
J Matern Fetal Neonatal Med. 2012 Sep;25(9):1544-8. doi: 10.3109/14767058.2011.653422. Epub 2012 Feb 13. Risk factors for wound complications in morbidly obese women undergoing primary cesarean delivery. Thornburg LL, Linder MA, Durie DE, Walker B, Pressman EK, Glantz JC. PMID: 22233403
METHODS: Retrospective cohort study evaluating infectious and separation WC in morbidly obese (body mass index [BMI] > 35 kg/m(2)) women undergoing primary CD between January 1994 and December 2008...RESULTS: Of 623 women, low transverse skin incisions were performed in 588 (94.4%), vertical in 35 (7%). Overall WC rate was 13.5%, which varied by incision type (vertical 45.7% vs. 11.6% transverse; p < 0.01), but not BMI class. Incision type and unscheduled CD were associated with infection risk, while incision type, BMI, race and drain use were associated with wound separation. CONCLUSION: In morbidly obese women both infectious and separation type WC are more common in vertical than low transverse incisions; therefore transverse should be preferred.
Am J Obstet Gynecol. 2017 Jul;217(1):85. doi: 10.1016/j.ajog.2017.06.002. Removal notice to The relationship between primary cesarean delivery skin incision type and wound complications in women with morbid obesity: Am J Obstet Gynecol 2014;210:319.e1-4. Marrs CC, Moussa HN, Sibai BM, Blackwell SC. PMID: 28648694
...The original publication reported that univariate analysis showed that a vertical skin incision in obese women undergoing Cesarean delivery was associated with a higher odds ratio for wound complications than a transverse skin incision. Multivariable analyses showed a reversal of the association (i.e. the odds of wound complications were lower in women with a vertical skin incision). However, there was an error in the way the variable was entered in the logistic analysis. Re-analysis with the correct coding of the variable indicates that a transverse skin incision is associated with decreased odds of wound complication compared to a vertical skin incision. 
Obstet Gynecol. 2014 Aug;124(2 Pt 1):227-32. doi: 10.1097/AOG.0000000000000384. Extreme obesity and postcesarean maternal complications. Stamilio DM, Scifres CM. PMID: 25004353
...This was a secondary cohort analysis of a randomized controlled trial... We included 585 women in the analysis. Eighty-five patients (14.5%) had BMIs higher than 45. ...Obese patients were more likely to have a cesarean delivery after labor and have a vertical skin incision or classical uterine incision. After controlling for confounders, extremely obese patients had a twofold to fourfold increase in postoperative complications, including the primary infectious outcome (18.8%, adjusted OR 2.7, CI 1.2-6.1), wound infection (18.8%, adjusted OR 3.4, CI 1.4-8.0), and emergency department visit (23.1%, adjusted OR 2.2, CI 1.03-4.9)....
Am J Perinatol. 2016 Apr;33(5):463-72. doi: 10.1055/s-0035-1566000. Epub 2015 Oct 28. The Problem of the Pannus: Physician Preference Survey and a Review of the Literature on Cesarean Skin Incision in Morbidly Obese Women. Smid MC, Smiley SG, Schulkin J, Stamilio DM, Edwards RK, Stuebe AM. PMID: 26510932
This study aims to determine preferences of a nationally representative sample of obstetrician/gynecologists (OB/GYNs) regarding cesarean delivery (CD) incision practices for women with morbid obesity (body mass index ≥ 40 kg/m(2))... 247 OB/GYNs completed the survey (42% response rate). In nonemergency CD of morbidly obese women, 84% of physicians preferred a Pfannenstiel skin incision... In emergency CD, 66% preferred a Pfannenstiel incision... and 20% a vertical incision....
Obesity and Antibiotic Dosing 

Obstet Gynecol. 2011 Apr;117(4):877-82. doi: 10.1097/AOG.0b013e31820b95e4. Effects of maternal obesity on tissue concentrations of prophylactic cefazolin during cesarean delivery. Pevzner L, Swank M, Krepel C, Wing DA, Chan K, Edmiston CE Jr. PMID: 21422859
...METHODS:Twenty-nine patients scheduled for cesarean delivery were stratified according to body mass index (BMI) category, with 10 study participants classified as lean (BMI less than 30), 10 as obese (BMI 30-39.9), and nine as extremely obese (BMI 40 or higher). All patients were given a dose of 2 g cefazolin 30-60 minutes before skin incision...RESULTS: Cefazolin concentrations within adipose tissue obtained at skin incision were inversely proportional to maternal BMI (r=-0.67, P<.001)...Although all specimens demonstrated therapeutic cefazolin levels for gram-positive cocci (greater than 1 microgram/g), a considerable portion of obese and extremely obese did not achieve minimal inhibitory concentrations of greater than 4 micrograms/g for Gram-negative rods in adipose samples at skin incision (20% and 33.3%, respectively) or closure (20.0% and 44.4%, respectively) ...CONCLUSION: Pharmacokinetic analysis suggests that present antibiotic prophylaxis dosing may fail to provide adequate antimicrobial coverage in obese patients during cesarean delivery.
Am J Obstet Gynecol. 2015 Sep;213(3):415.e1-8. doi: 10.1016/j.ajog.2015.05.030. Epub 2015 May 21. Increased 3-gram cefazolin dosing for cesarean delivery prophylaxis in obese women. Swank ML, Wing DA, Nicolau DP, McNulty JA. PMID: 26003059
OBJECTIVE: The purpose of this study was to determine tissue concentrations of cefazolin after the administration of a 3-g prophylactic dose for cesarean delivery in obese women (body mass index [BMI] >30 kg/m(2)) and to compare these data with data for historic control subjects who received 2-g doses... RESULTS: Twenty-eight obese women were enrolled in the current study; 29 women were enrolled in the historic cohort. BMI had a proportionally inverse relationship on antibiotic concentrations. An increase of the cefazolin dose dampened this effect and improved the probability of reaching the recommended MIC of ≥8 μg/mL...With 2 g of cefazolin, only 20% of the cohort with a BMI of 30-40 kg/m(2) and none of the cohort with a BMI of >40 kg/m(2) reached an MIC of ≥8 μg/mL. With 3-g, all women with a BMI of 30-40 kg/m(2) reached target MIC values; 71% of the women with a BMI of >40 kg/m(2) attained this cutoff. CONCLUSION: Higher adipose concentrations of cefazolin were observed after the administration of an increased prophylactic dose. This concentration-based pharmacology study supports the use of 3 g of cefazolin at the time of cesarean delivery in obese women....
Obstet Gynecol. 2015 Oct;126(4):708-15. doi: 10.1097/AOG.0000000000001064. Obstetric Surgical Site Infections: 2 Grams Compared With 3 Grams of Cefazolin in Morbidly Obese Women. Ahmadzia HK, Patel EM, Joshi D, Liao C, Witter F, Heine RP, Coleman JS. PMID: 26348186
...A retrospective cohort study of morbidly obese pregnant women undergoing cesarean delivery was conducted at two tertiary care centers from 2008 to 2013. Exposure was defined as receiving 2 g compared with 3 g cefazolin preoperatively...There were 335 women included in the cohort with a median absolute weight of 310... pounds... There was no difference in surgical site infection among those women who received 2 g compared with 3 g cefazolin (13.1% [23/175] compared with 13.1% [21/160]; P=.996). Labor (crude odds ratio [OR] 2.31, 95% confidence interval [CI] 1.21-4.40), internal labor monitoring (OR 2.78, 1.45-5.31), blood loss greater than 1,500 mL (OR 2.15, 1.09-5.78), and staple closure (OR 2.2, 1.15-4.21) were associated with a surgical site infection among the entire cohort. After multivariable analysis, blood loss... (adjusted OR 3.32, 1.32-8.37) and staple closure (adjusted OR 2.45, 1.19-5.02) remained associated with an increased risk for a surgical site infection, whereas 3 g cefazolin still was not associated with reduced risk for a surgical site infection (adjusted OR 1.33, 0.64-2.74). CONCLUSION: In our multicenter retrospective cohort study, preoperative 3 g cefazolin prophylaxis administered to morbidly obese gravid patients did not reduce surgical site infections.
Obstet Gynecol Surv. 2017 Aug;72(8):500-510. doi: 10.1097/OGX.0000000000000469. Body Mass Index 50 kg/m2 and Beyond: Perioperative Care of Pregnant Women With Superobesity Undergoing Cesarean Delivery. Smid MC, Dotters-Katz SK, Silver RM, Kuller JA. PMID: 28817167
...Currently, 2% of pregnant women in the United States are superobese, and 50% will deliver via cesarean delivery. ... There is limited information to direct evidence-based care of superobese women who undergo cesarean delivery. Superobese women have a 30% to 50% risk of wound complications...Preoperative cefazolin with a 3-g dose, chlorhexidine skin preparation, and availability of adequate personnel for patient transfers are important evidence-directed approaches to reducing maternal and personnel morbidity. Postoperatively, early ambulation and chemical prophylaxis are reasonable, although there is a lack of evidence as to whether these measures prevent thromboembolic complications... Most evidence-directed recommendations for perioperative care are extrapolated from studies of obese women undergoing bariatric surgery. As the prevalence of reproductive-age women with superobesity increases, studies directed at this high-risk population are urgently needed.
JAMA. 2017 Sep 19;318(11):1026-1034. doi: 10.1001/jama.2017.10567. Effect of Post-Cesarean Delivery Oral Cephalexin and Metronidazole on Surgical Site Infection Among Obese Women: A Randomized Clinical Trial. Valent AM, DeArmond C, Houston JM, Reddy S, Masters HR, Gold A, Boldt M, DeFranco E, Evans AT, Warshak CR. PMID: 28975304
...Randomized, double-blind clinical trial comparing oral cephalexin and metronidazole vs placebo for 48 hours following cesarean delivery for the prevention of SSI in obese women (prepregnancy BMI ≥30) who had received standard intravenous preoperative cephalosporin prophylaxis. Randomization was stratified by intact vs rupture of membranes prior to delivery...Participants were randomly assigned to receive oral cephalexin, 500 mg, and metronidazole, 500 mg (n = 202 participants), vs identical-appearing placebo (n = 201 participants) every 8 hours for a total of 48 hours following cesarean delivery. ...RESULTS: ...Surgical site infection was diagnosed in 13 women (6.4%) in the cephalexin-metronidazole group vs 31 women (15.4%) in the placebo group (difference, 9.0% [95% CI, 2.9%-15.0%]; relative risk, 0.41 [95% CI, 0.22-0.77]; P = .01). ...CONCLUSIONS AND RELEVANCE: Among obese women undergoing cesarean delivery who received the standard preoperative cephalosporin prophylaxis, a postoperative 48-hour course of oral cephalexin and metronidazole, compared with placebo, reduced the rate of SSI within 30 days after delivery. For prevention of SSI among obese women after cesarean delivery, prophylactic oral cephalexin and metronidazole may be warranted.
Obesity and Sutures vs. Staples

Am J Perinatol. 2014 Apr;31(4):299-304. doi: 10.1055/s-0033-1348402. Epub 2013 Jun 13. Maternal obesity and risk of postcesarean wound complications. Conner SN, Verticchio JC, Tuuli MG, Odibo AO, Macones GA, Cahill AG. PMID: 23765707  Full text found here.
...STUDY DESIGN: We performed a retrospective cohort study of consecutive cesarean deliveries at a tertiary care facility from 2004 to 2008. Four comparison groups were defined by body mass index (BMI; kg/cm2): < 30 (n = 728), 30 to 39.9 (n = 1,087), 40 to 49.9 (n = 428), or ≥ 50 (n = 201). ...RESULTS: Of the 2,444 women with complete follow-up data, 266 (10.9%) developed a wound complication. Compared with nonobese women (6.6%), increasing BMI was associated with an increased risk of wound complications: BMI 30.0 to 39.9, 9.2%;... BMI 40.0 to 49.9, 16.8%;... BMI ≥ 50, 22.9%... Increasing BMI was also associated with increased rates of midline vertical incision, longer operative time, higher EBL [estimated blood loss], and lower rates of subcuticular skin closure....
J Perinatol. 2016 Oct;36(10):819-22. doi: 10.1038/jp.2016.89. Epub 2016 Jun 2. Wound complications in obese women after cesarean: a comparison of staples versus subcuticular suture. Zaki MN, Truong M, Pyra M, Kominiarek MA, Irwin T. PMID: 27253895
...We conducted a retrospective cohort study to compare wound complications between staples and subcuticular suture closure in women, with a prepregnancy BMI⩾30... after CD between 2006 and 2011 at an inner-city teaching hospital... RESULTS: Of the 1147 women included in the study, ...Women with staples had higher wound complications compared with sutures (22.0% versus 9.7%) with a 2.27 unadjusted relative risk (RR) (95% confidence interval (CI), 1.7 to 3.0) and 1.78 adjusted RR (95% CI, 1.27 to 2.49) after controlling for confounders in the final analysis, including vertical skin incisions. CONCLUSIONS: In obese women, skin closure with staples at the time of CD is associated with a higher rate of wound complications compared with subcuticular suture. Skin closure with subcuticular suture over staples should be considered in obese women undergoing a CD regardless of skin incision type.
Obesity and Thromboprophylaxis

J Perinatol. 2016 Feb;36(2):95-9. doi: 10.1038/jp.2015.130. Epub 2015 Dec 10. A randomized controlled trial of differing doses of postcesarean enoxaparin thromboprophylaxis in obese women. Stephenson ML, Serra AE, Neeper JM, Caballero DC, McNulty J. PMID: 26658126
...To compare two enoxaparin dosing strategies at achieving prophylactic anti-Xa levels in women with a body mass index (BMI) ⩾35 (kg m(-2)) postcesarean delivery. STUDY DESIGN: Women with BMI ⩾35 were randomized to receive prophylactic enoxaparin at a fixed dose of 40 mg daily or weight-based dosing of 0.5 mg kg(-1) twice daily. ...In the weight-based group, 88% (37/42) of the women reached prophylactic anti-Xa levels versus 14% (6/42) in the fixed dose group (odds ratio 44.4, 95% confidence interval 12.44, 158.48, P<0.001)...There were no venous thromboembolic or bleeding events requiring reoperation or transfusion in either group. CONCLUSION: Compared with fixed dosing daily, weight-based dosing twice daily more effectively achieved prophylactic anti-Xa levels without reaching the therapeutic range.
Obesity and Subcutaneous Tissue Approximation

Obstet Gynecol. 2004 May;103(5 Pt 1):974-80. Suture closure of subcutaneous fat and wound disruption after cesarean delivery: a meta-analysis. Chelmow D, Rodriguez EJ, Sabatini MM. PMID: 15121573  Full text here
...CONCLUSION: Suture closure of subcutaneous fat during cesarean delivery results in a 34% decrease in risk of wound disruption in women with fat thickness greater than 2 cm.
Obesity and Surgical Drains

Am J Obstet Gynecol. 2010 Sep;203(3):271.e1-7. doi: 10.1016/j.ajog.2010.06.049. Epub 2010 Aug 3. Complications of cesarean delivery in the massively obese parturient. Alanis MC, Villers MS, Law TL, Steadman EM, Robinson CJ. PMID: 20678746
...This was an institutional review board-approved retrospective study of massively obese women (body mass index, > or = 50 kg/m(2)) undergoing cesarean delivery... Fifty-eight of 194 patients (30%) had a wound complication...Subcutaneous drains and smoking, but not labor or ruptured membranes, were independently associated with wound complication after controlling for various confounders. Vertical abdominal incisions were associated with increased operative time, blood loss, and vertical hysterotomy. CONCLUSION: Women with a body mass index > or = 50 kg/m(2) have a much greater risk for cesarean wound complications than previously reported. Avoidance of subcutaneous drains and increased use of transverse abdominal wall incisions should be considered in massively obese parturients to reduce operative morbidity.
Obstet Gynecol. 2005 May;105(5 Pt 1):967-73. Subcutaneous tissue reapproximation, alone or in combination with drain, in obese women undergoing cesarean delivery. Ramsey PS, White AM, Guinn DA, Lu GC, Ramin SM, Davies JK, Neely CL, Newby C, Fonseca L, Case AS, Kaslow RA, Kirby RS, Rouse DJ, Hauth JC. PMID: 15863532
...We conducted a multicenter randomized trial of women undergoing cesarean delivery. Consenting women with 4 cm or more of subcutaneous thickness were randomized to either subcutaneous suture closure alone (n = 149) or suture plus drain (n = 131)...RESULTS: From April 2001 to July 2004, a total of 280 women were enrolled. Ninety-five percent of women (268/280) had a follow-up wound assessment...The composite wound morbidity rate was 17.4% (25/144) in the suture group and 22.7% (28/124) in the suture plus drain group (relative risk 1.3, 95% confidence interval 0.8-2.1)...CONCLUSION: The additional use of a subcutaneous drain along with a standard subcutaneous suture reapproximation technique is not effective for the prevention of wound complications in obese women undergoing cesarean delivery.
Negative Pressure Wound Therapy and Obesity

AJP Rep. 2017 Jul;7(3):e151-e157. doi: 10.1055/s-0037-1603956. Epub 2017 Jul 14. Closed-Incision Negative-Pressure Therapy in Obese Patients Undergoing Cesarean Delivery: A Randomized Controlled Trial. Gunatilake RP, Swamy GK, Brancazio LR, Smrtka MP, Thompson JL, Gilner JB, Gray BA, Heine RP. PMID: 28717587
...We compared surgical site occurrences (SSOs) in cesarean patients receiving closed-incision negative-pressure therapy (ciNPT) or standard-of-care (SOC) dressing. STUDY DESIGN: A single-center randomized controlled trial compared ciNPT (5-7 days) to SOC dressing (1-2 days) in obese women (body mass index [BMI] ≥ 35), undergoing cesarean delivery between 2012 and 2014...CONCLUSION: A trend in SSO reduction and a statistically significant reduction in postoperative pain and narcotic use was observed in women using ciNPT.
Obstet Gynecol. 2017 Nov;130(5):969-978. doi: 10.1097/AOG.0000000000002259. Prophylactic Negative Pressure Wound Therapy for Obese Women After Cesarean Delivery: A Systematic Review and Meta-analysis. Smid MC, Dotters-Katz SK, Grace M, Wright ST, Villers MS, Hardy-Fairbanks A, Stamilio DM. PMID: 29016508
...In the meta-analysis, there was no difference in primary composite outcome among those women with negative pressure wound therapy (16.8%) compared with those who had standard dressing (17.8%) (risk ratio 0.97, 95% CI 0.63-1.49)...CONCLUSION: Currently available evidence does not support negative pressure wound therapy use among obese women for cesarean wound complication prevention.
Morbidity of Multiple Cesareans in Obese Women

J Matern Fetal Neonatal Med. 2015 Jun;28(9):989-93. doi: 10.3109/14767058.2014.941284. Epub 2014 Jul 24. The effect of maternal obesity on outcomes in patients undergoing tertiary or higher cesarean delivery. Mourad M, Silverstein M, Bender S, Melka S, Klauser CK, Gupta S, Saltzman DH, Rebarber A, Fox NS. PMID: 25058127
...Retrospective cohort of patients cared for by a single MFM practice undergoing a tertiary or higher cesarean delivery from 2005 to 2013...The primary outcome was a composite of severe maternal morbidity (uterine rupture, hysterectomy, blood transfusion, cystotomy requiring repair, bowel injury requiring repair, intensive care unit admission, thrombosis, re-operation, or maternal death). RESULTS: ...The composite outcome was significantly higher in the obese group (6.8% versus 1.8%, p = 0.024, aOR 4.36, 95% CI 1.21, 15.75). The incidence of several individual adverse outcomes were also increased in obese women, including blood transfusion (4.1% versus 0.7%, p = 0.033, aOR 7.36, 95% CI 1.19, 45.34), wound separation or infection (20.5% versus 5.9%, p < 0.001, aOR 4.05, 95% CI 1.75, 9.36) and 1-min Apgar score less than 7 (6.8% versus 1.9%, p = 0.024, aOR 4.40, 95% CI 1.21, 15.94). CONCLUSIONS: In patients undergoing a tertiary or higher cesarean delivery without placenta previa or accreta, obesity increases the risk of adverse outcomes. Obese patients are at risk for blood transfusion, low 1-min Apgar scores and postoperative wound complications.