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 OT. Often 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

Manual Rotation for Posterior or Tranverse Babies

This new study is just the latest in a series of studies that have shown that manual rotation lessens the need for cesarean during labor because of a malpositioned baby. 

In these studies, a persistent posterior baby (baby facing mom's tummy instead of her back) is turned manually to the generally-easier-to-birth anterior position (baby facing mom's back). The question has been whether such techniques improve outcomes. 

This study shows a dramatic improvement in outcomes with manual rotation.

This is a larger trial than many of the previous studies on manual rotation, which makes the findings even stronger.  This study is interesting in that it also includes manual rotation for transverse arrest (baby gets stuck facing sideways, usually as they are trying to rotate from posterior to anterior).  Not all manual rotation studies do.

Note that manual rotation is not without risks; there were more women in the rotation group with cervical lacerations, which is not fun.  However, balance that against less need for cesareans, fewer severe perineal lacerations, less hemorrhage, and less infection, and I'd say manual rotation wins, hands down.

But Should We Intervene for a "Malpositioned" Baby?

One of the controversies within the natural childbirth community these days is whether persistent posterior babies should be considered malpositions or just variations of normal, and whether we really need to intervene at all in such cases or just be more patient. 

Personally, I do believe that sometimes these positions are just a variation of normal and don't have to be a big deal.  Sometimes all that's needed is just a tincture of patience and time, and the "malpositioned" baby is born just fine.  Sometimes the baby's "malposition" is even actually needed because of a unique pelvic shape or some other factor we are not yet aware of.  So I agree─up to a point─with folks who tell pregnant women not to obsess too much over their baby's position or to feel that if they have a posterior baby that they are doomed to a cesarean etc. 

However, I think it's naive to believe that such positions are always benign and will always be born vaginally and without damage if just given enough time.  I think research is quite clear that OP labors are often harder and longer, and that there are often poorer outcomes for mother and baby. 

Yes, I do wish doctors would also study maternal repositioning and other less interventive alternatives so there were other options in the arsenal for a malpositioned baby.  I bet some of these babies would rotate just fine with other, less-invasive techniques, and then the more-invasive manual rotation could be used only when truly needed.   I also wish that care providers would be more patient in labors, because many positions will remedy themselves with a little extra time, or be born in that position just fine.

However, I don't believe that all malpositioned babies will be born safely "if just given enough time." Some babies and mothers will experience significant difficulties.  Many more will be subjected to forceps/vacuum extraction and cesarean deliveries, with all the associated risks. The question is whether these complications and operative deliveries could have been avoided if manual rotation had just been tried.

This new study compared manual rotation with expectant management─just waiting─and found that outcomes were significantly improved in the active intervention group.  Other studies have also found that prophylactic rotations improved outcomes. So perhaps "just waiting" is not always the best thing.

Remember, these malposition labors can sometimes be just HELL for both mother and baby. It's not always wise to wait to intervene until mother is exhausted and baby is in distress. Sometimes an earlier intervention like manual/digital rotation can be judicious and helpful. 

So while I want care providers to have more patience and use other, less invasive techniques first, I am thankful that manual rotation is in the arsenal too.  I think the results of these studies clearly show it should be learned by more care providers and applied when less-invasive techniques are not helping.

For the many many MANY of us out there who have had long hard labors and then cesareans for malpositioned babies, I say Hallelujah that care providers are re-learning this manual repositioning skill again.  About time! 

Huge thanks to the midwives and doctors who kept this technique alive when it went out of obstetric fashion.  I hope they are teaching others and spreading the word to more midwives and especially doctors.  Far too many women are being cut open because care providers don't know how to handle differences in fetal position. 

Manual repositioning can be a very valuable skill to have and will surely improve outcomes in many cases.  That doesn't mean it should be used too quickly or in place of less-interventive techniques, but that it clearly does have a place in the spectrum of options.


Shaffer BL, Cheng YW, Vargas JE, Caughey AB.  Manual rotation to reduce caesarean delivery in persistent occiput posterior or transverse position. J Matern Fetal Neonatal Med 2011 Jan;24(1):65-72. Epub 2010 Mar 30.   PMID: 20350240

Division of Maternal Fetal Medicine, Department of Obstetrics, Gynecology and Reproductive Sciences, Center for Clinical and Policy Perinatal Research, University of California, San Francisco, CA 94143-0705, USA.

OBJECTIVE:

To examine mode of delivery and perinatal outcomes in women with occiput posterior (OP) or transverse (OT) position in the second stage of labour with a trial of manual rotation compared to expectant management.

METHODS:

A retrospective cohort study was designed to examine mode of delivery and perinatal morbidity in women who underwent a trial of manual rotation (n = 731) compared to expectant management (n = 2527) during the second stage of labour with the fetus in OP/OT position. Chi-square test was used to compare categorical outcomes and multivariable logistic regression models were used to control for potential confounders.

RESULTS:

Compared to expectant management, women with manual rotation were less likely to have: caesarean delivery (CD) [adjusted odds ratio (aOR) 0.12; 95% confidence interval (CI) 0.09-0.16], severe perineal laceration [aOR 0.64; (0.47-0.88)], postpartum haemorrhage [aOR 0.75; (0.62-0.98)], and chorioamnionitis [aOR 0.68; (0.50-0.92)]. The number of rotations attempted to avert one CD was 4. In contrast, women who had a trial of rotation had an increased risk of cervical laceration [aOR 2.46; (1.1-5.4)].

CONCLUSIONS:

Compared with expectant management, a trial of manual rotation with persistent fetal OP/OT position is associated with a reduction in CD and adverse maternal outcomes.

Belly Thoughts

So, for those of you who have been pregnant, how did you feel about your pregnant belly?  How did you feel during pregnancy?  After pregnancy, with the post-mummy tummy?  Years later?

I was reflecting the other day on my relationship to my belly, especially in regards to my pregnancies and births ─ how I've celebrated it in some ways, and how I've struggled with it in other ways. 

I thought about things that I expected to happen and how the reality did or didn't meet those expectations, things that surprised me, things that pleased me, and things that made me unhappy or which challenged my peace with my body. 

Thought I'd share some of those thoughts here.  Hope you will share your own experiences too.

Trigger Warning:  Frank talk about body ambivalence and negativity. Some folks may find this post challenging or triggering and may want to opt out.


Worrying About Shamu

My first pregnancy was a surprise.  I went from being told I would not be able to get pregnant without "help" to being pregnant a few months later without trying.  So I was totally not prepared to think about pregnancy bellies! 

I hate to say it now because it sounds so vain, but I was really worried about what I'd look like pregnant.  I was already a large person; I figured when I was pregnant I'd look like Shamu. 

Now, I don't mean that in a negative way; I was pretty at peace with my body pre-pregnancy, and I didn't really "fear" being huge in pregnancy.  But I was having a hard time picturing the giant basketball belly you see on skinny women added to my already sizable frame, you know?  And I wondered what I'd be wearing on that basketball belly (or if I could find anything to wear at all, considering that it wasn't easy to find clothes even when not pregnant).

I know a lot of other women of size wonder these things too, because the top post viewed on this blog (by a HUGE margin) is the one on plus-sized pregnancy photos.  There are so few pictures of women of size out in the media, let alone pregnant women of size.  (And fat pregnant women of color?  Nearly impossible to find. Gah!)

The most common search words people use when they find my blog has to do with this search for images of fat pregnant women.  Except the phrases are usually "overweight and pregnant photos" or "obese pregnant belly" or "obese pregnancy pictures" or "plus-size pregnancy belly pics" and things like that.  There is a tremendous desire for pictures of pregnant women of size because I think so many fat women have that "Oh-My-God-What-Am-I-Going-To-LOOK-Like" anxiety. 

The Shamu obsession, I call it.

The Not-Looking-Pregnant-Surprise

The ironic gotcha to all that worry is that once I was well into pregnancy, I was disappointed to realize that I didn't look pregnant at all. 

People kept looking at me and wondering where the pregnancy belly was, I could see it in their eyes.  Well, it was there ─ it just wasn't visible to the casual onlooker.  I have a big ole rack-o-doom and that tends to hide any belly popping out pretty well, plus my baby was facing my belly (occiput posterior) for much of the pregnancy, which means you "show" a lot less (cause the baby's behind is facing the other way!). 

I was so NOT showing in pregnancy that most people couldn't even tell I was pregnant until the baby was nearly born.  My classic story of this was when I had to move during my 8th month of pregnancy.  I showed up to my new doctor's office, told them I was transferring care there from another state ─ and they eyed me and asked me if I needed a pregnancy test!  I said, uh no, I'm 8 months pregnant already and if you need confirmation, you can come over here and feel her kicking!  They still looked dubious but took my word for it. I was so upset that they couldn't tell I was pregnant even at that point.

The only time anyone knew I was pregnant was just before I gave birth at 40 weeks.  I was in an elevator, going up to my last OB appointment, and a doctor on the elevator remarked on my pregnancy (he didn't know me; he was just being kind and making small talk).  I could have kissed him!!  Finally, FINALLY, someone saw I was pregnant.

So in the beginning, I was most worried about just how large I might get in pregnancy, only to have the ironic problem of no one even knowing I was pregnant most of the time.  Some fat women do look obviously pregnant, but some don't.  A lot depends on factors like the position of the baby, your shape ("pears" show more than "apples" or "hourglasses"), and your overall frame. 

If you are bothered by folks not knowing you are pregnant, the secret is to wear obvious maternity clothing, stand with your hand massaging your belly a lot, and talk a lot about your pregnancy.  That will make it clear to all but the most oblivious by-stander that it's not just fat but actual baby in there too.  (Sad we have to be so OBVIOUS about it, but hey, if it brings you peace of mind, go for it.)

The Hard-Belly-Surprise

The biggest thing that surprised me about my actual pregnant belly was that it was hard. 

I was used to my belly being a bit more on the soft and squishy side ─ not flabby but not rock-hard either.  But in pregnancy, my "bump" was quite hard and that really surprised me.

The not-so-lovely part of this was that the squishy parts then drooped down to the underside of the baby bump and I developed an "overhang" that I'd never had before.  Eywww.

Now, I'm generally a lot more self-accepting than most but even I had trouble being loving and accepting of the big belly droop that sent all my fat south for the winter.  Permanently. 

That was a not-so-pleasant surprise.

And it only got worse with each kid. 

Four of 'em.

The Postpartum-Belly Reality

I have to be frank about this ─ this belly droop thing has been hard to deal with.  Honestly, it's not a part of my body that I'm so at peace with anymore. 

Hard as it may be for some people to believe, I really was okay with my belly before babies.  It wasn't flat, it did have a bit of a roll, but nothing all that remarkable. I carried more of my weight in my boobs, hips, and legs.  I was okay with my belly.  I wasn't photographing it and sending it off to magazines, but I really didn't hate it and I really did enjoy the fact that my waist was so much smaller than my hips, giving me that va-va-va-voom hourglass vibe. 

But post-children ─ oy.  The va-va-va-voom factor?  It va-va-va-vrooomed off to another universe.  The belly droops down now in a way it never did before.  If I move in just the "right" way, I can hear the "slap-slap-slap" sound of my flesh hitting against itself.  It never did that before children!  Oh my gosh, I cannot tell you how much I absolutely loathe that.

And that hourglass figure?  Well, it's not a straight line but it's closer.  I gained a lot of abdominal fat in my pregnancies, and I dislike that for a number of reasons, both aesthetic and more importantly, because abdominal visceral fat is much more of a health risk.  I used to be very much a pear, or at least an hour-glassy pear with boobs.  Now I gained an apple to add to the pear with boobs, leaving me just fat all over.  That didn't make me very happy. I don't mind being fat, but I really liked actually having a shape.  Now, I feel more like a blob.

The extra abdominal fat certainly wasn't from gaining "too much" weight.  I gained a total of 5 lbs. net (lost 10 or so and then regained 15) on average with each child.  I bounced around a bit between each but ended up at about the same weight I started my first pregnancy.  However, you'd never know it from looking at me.  I look quite a bit heavier now than I did before my pregnancies.  And that sucks, I have to say.

It sucks not because I'm fat but because I look a lot fatter than I really am.  I basically am the same weight as 16+ years ago....but I sure look a lot heavier.  I'm not thrilled with that ─ but the real reason it sucks is because I know from the research that abdominal fat really is more risky. Even though I didn't gain "too much" and even though my eating habits actually improved from pre-pregnancy....I look more at risk, and probably am more at risk.  Damn.

The Lipedema Effect

As a side note of interest, I should point out that the bellyfat gain is probably due to lipedema (warning: not a fat-acceptance link).

People with lipedema (not the same as lymphedema) have a tendency to gain abnormal fat deposits in the lower body, especially the legs, but sometimes also in the abdomen or upper arms. They often gain a lot of these fat reserves during times of major hormonal changes, like puberty, pregnancy, menopause, etc.

My legs look just like the picture here, my legs got bigger symmetrically, I have the classic "cankles" with the ring overlap at the bottom yet my feet are not affected, and it is extremely painful to have any pressure on my legs, especially my lower legs.

While the lipedema fat gain did happen a bit, it was not too bad with the first few pregnancies. However, in the fourth pregnancy (in my 40s), the combination of pregnancy plus perimenopause plus postpartum thyroiditis did seem to add an awful lot of fat, both around my ankles and in the abdominal area.

So while I'm technically at the same weight I started my pregnancies out with, my fat levels have definitely increased, and that's been difficult to be at peace with.

Now, the belly droop thing is pretty common among women of size after pregnancy.  Fat women often experience this, regardless of how much weight they gained, how they gave birth, etc.  (Some get it without pregnancy too, especially if they've had a lot of drastic weight loss/regain in their lives.) 

But mine may be worse because of my 2 cesareans, because many women (fat or skinny) who have had cesareans find they have a post-cesarean "shelf" or "flap."  I'm sure some would be there anyhow without cesareans, but most cesarean moms really do see a marked increase on the belly flap-o-meter, and I'm sure being fat and having lipedema and having had cesareans only magnified that lovely effect.  [Another *#ing gift from my cesareans!]

So all in all, I've had some real challenges to my body acceptance after four children.

Belly Ambivalence

I take some comfort in knowing I'm not alone in my belly ambivalence, though.  A lot of women have droopy bellies postpartum, a ton of stretch marks, and a different overall shape than before. 

A change that drastic ─ well, it's just not that easy to come to terms with, no matter how much you love your body in general, or how much you adore your babies and wouldn't trade them for the world. So having a hard time coming to peace with your body afterwards is very normal, as you can see here:

http://www.theshapeofamother.com/

Beware, though, this is not a body-acceptance or fat-acceptance site at all.  These women have all the self-hate of their bodies (and especially their fat bodies) that is so typical of women in our society.  Add in the wrinkly, saggy belly that is universal immediately postpartum, and the body hate talk there can be really strong at times.  So while the pictures at Shape of a Mother are great to see, you should know that the self-hate talk may be triggering for some. 

Personally, I still find the site useful, even though I find the self-loathing and pro-dieting talk frustrating. I try to remember that it does reflect the ambivalent feelings many women have about their bodies post-partum ─ magnifying whatever body image issues they already had pre-pregnancy ten-fold.  Plus I just don't know any other sites out there that have such honest pictures of postpartum bodies. So I value the absolute honestly of the pictures themselves enough to try and overlook the self-hate talk.

Here is the link to the category of pictures of pregnancy and post-pregnancy bellies in women of size:

http://theshapeofamother.com/category/plus-sized/

[Again, be warned that there's lots of diet talk and WLS (weight loss surgery) discussion there.]

Belly Honor

No, it's not easy to stay at peace with your body (and especially your belly) during pregnancy and post-partum.  There are many challenges to body image, and the natural changes that come with pregnancy can exacerbate the body image issues of even the most self-accepting woman.

Still, it's important to honor the vital work that our bodies did, to love every bump and curve for the job it did bringing a new soul to the earth, growing a healthy being and helping it into this world, and nurturing that new life afterwards.

I guess my main message on this is that it's normal and okay to be a bit ambivalent about your body shape and condition after birth (even long after birth).  Don't hate on it, recognize the important work it did ─ but realize that it's totally normal to have some ambivalence about it too.

Acknowledge that, and then take some time to honor your belly anyway. 

To honor my belly despite my ambivalence, here are some shots of me several years ago in my last pregnancy.  I was "overdue" and impatient to have the baby, but I'd been down the Seduction to Induction Road before, knew how often it leads to a cesarean, and refused to get lured into that trap again.  So I was waiting....and waiting....and waiting...and waiting.  Baby didn't come until nearly 43 weeks by LMP (nearly 42 by adjusted dates).  Augh!

So to distract myself and to have some fun in those last few days, I put on my oldest, ugliest painting clothes, gave my kids a bunch of washable tempera paint, went out into the back yard, stuck out my belly, and gave them a new and unique painting canvas. 

They were young; the resulting artwork is probably not beautiful to anyone in the world except me, but we had a BLAST.   

I remember that belly-painting session with tremendous fondness.  I hope they do too. 

So I honor my belly, stretched out and saggy and droopy as it was (and still is), for all the work it did bringing my wonderful babies to me, like this one, below. [Yes, she is the one in-utero above.]

It was totally worth it, every bit of it.  

Enjoy. And find a way to honor your bellies, too.

*Art Docent Hints: If you enjoy a good mystery and want to try and deciper the painting, look for the picture of the baby they drew.  Look for the green head with a brownish arm sticking out to the side underneath (the rest of the body is a bit amorphous, I'm afraid). Also look for the word "baby" on the side.  There was an arrow below it, pointing to the baby, but it got obliterated by an overenthusiastic toddler.  Then they filled in the blank spaces with random colors and swirls. The final result was a bit Picasso-ish, but hey. 

**Fetal Position Postscript: For the curious, yes, in this picture my baby bump is really quite visible, but then my baby in this pregnancy was in the most optimal position for birth, which is anterior.  That means the little butt was sticking out in front, making a nice big bump to paint on.  In my first pregnancy, when I didn't look pregnant at all, baby was posterior and in that position the baby butt doesn't stick out and make much of a discernible bump.  The difference? I saw a pregnancy-trained chiropractor and got some adjustments.  That made my last pregnancy SO much more comfortable, and it helped baby to be anterior after 3 prior pregnancies with a posterior baby!  Trust me, that's a MUCH easier labor!

The Fat Vagina Theory: "Soft Tissue Dystocia"

One common misconception that many birth attendants have about labor in women of size is the "fat vagina" theory.

In this theory, birth attendants believe that women of size have a lot of extra fat tissue internally, crowding the maternal pelvis and birth canal.  Extra fat tissue then supposedly gets in the way and obstructs the passage of the baby through the bony pelvis and/or vagina.

In medical research they call this "soft tissue dystocia," but sometimes doctors will patronizingly explain it to patients as the "fat vagina" theory.

[Note: "Fat Vagina" is an actual term used by an OB to tell a friend of mine from ICAN why she had a cesarean ─ she was told her morbid obesity made her vagina "too fat" to let the baby out during labor ─ and she's not the only one who has been told that.  So although my sarcasm meter is certainly on when I use it, that's really a term that has been used with some women of size.]

Alas, it's not just doctors who buy into the "fat vagina" theory.  One TV birth show featuring a midwifery practice even promoted this same theory, encouraging a fat woman who wanted a Vaginal Birth After Cesarean (VBAC) at their birthing center to lose weight during pregnancy in order to "decrease the fat deposits in the vagina" and "make it possible" for the woman to have a VBAC. (As if no fat woman has ever had a VBAC without losing weight!  Sorry, they have. And so have I.)

Or there's the story one of my blog's readers emailed to me:

[The midwife] said I will have a large fat buildup around my birth canal and uterus so baby will get stuck in a natural birth. 

Alas, this "fat vagina" belief is a theory near and dear to many birth attendants' hearts.  They have been taught in medical or midwifery school that "soft tissue dystocia" is the cause of many cesareans in fat women, and they believe it with all of their hearts.  It's very difficult to get them to question its existence. 

But what does the evidence say? 

The Research, Such As It Is

One of the most frustrating aspects of the whole "fat vagina" theory is how little actual evidence there is on it, yet it is taught as if it is clearly established science. 

One study (Crane 1997) describes it as a possible reason for a higher primary cesarean rate in "obese" women:

Perhaps dystocia due to an increased deposition of soft tissues in the maternal pelvis may lead to the observed increase in the cesarean delivery rate.

One review (Vahratian 2005) noted that many studies attribute the increased rate of cesareans in "obese" women to soft tissue dystocia but that few prove it.

Several authors have speculated that this association [between obesity and cesarean rates] may be due to the added soft-tissue deposits in the pelvis of obese women, which coupled with a larger fetus might necessitate more time and stronger contractions to progress through labor.  However, direct evidence of fat deposition in the pelvis is needed to support this assertion.

The study noted that as yet, the authors promoting this theory have failed to provide this evidence.

Most studies discuss increased maternal fat deposits as if it is a proven concept, but no one has actually done much study showing a real difference in maternal fat compartments, let alone proven that it affects labor.

Barau et al., 2006, also favors the concept of soft tissue dystocia but acknowledges that:

There is no direct support of this concept by medical imagery studies.

So why are healthcare providers so devoted to this theory when there is very little actual proof of it? 

Most of the time, practitioners believe in the concept of soft tissue dystocia because they know that visceral fat can build up around internal abdominal organs, so they speculate that a similar thing must be happening in the maternal pelvis.

Furthermore, they often observe more tissue during pap smears in "morbidly obese" women, sometimes needing to use a larger speculum in order to hold open the vaginal vault and do the exam.  Therefore, they jump to the conclusion that there is more fat "crowding" the pelvis of women of size, and that therefore, this must be obstructing the passage of the baby through the mother's pelvis.

But just because a fat woman's vagina tends to have more tissue to hold back with a speculum does not necessarily mean that there is enough fat way up inside the pelvis (pelvic inlet) or at the pelvic outlet to be clinically significant.  

Remember, because the considerable weight of a fat woman's abdomen presses down with the weight of gravity, it may tend to make the vaginal walls more prone to collapse and look overly crowded, but it may not actually be so, or not enough to make much difference. And even if there was somewhat more tissue in a fat woman's vaginal area, remember......fat squishes.  It's unlikely that there would be enough tissue there to actually impede a baby's exit, even in very fat women. 

The one study we do have that actually did medical imagery to discover whether there are extra maternal fat deposits in the pelvis does not support the idea that there is enough extra soft tissue to be relevant to birth.

Wischnik (1992) did a study on the "fatty pelvis" to see whether fat compartments within the pelvis actually resulted in "functional reduction of the birth channel diameters."  They found slightly more fat compartments, but did not find it to be clinically relevant.  They concluded:

The common assumption can no longer be maintained, that adiposity necessarily causes soft tissue dystokia  [sic] due to larger fat compartments within the small pelvis.

So from a strictly evidence-based point of view, there is no substantiated medical evidence of enough increased deposits to be medically significant. 

All we have is the observation that there is slightly more tissue pushing in and thus more need for a stronger speculum during the pap smears of women of size. 

I think most medical providers then take a leap of logic and conclude that if fat women's babies don't come out as easily as skinny women's babies, it must be due to fat blocking the way....and the need for a bigger speculum during a GYN exam in some women of size just seems to confirm that bias. 

But I think they need to look more closely at this assumption.

Alternative Explanations

Unfortunately, despite a glaring lack of evidence, soft tissue dystocia is a concept that continues to be taught and widely believed. 

Barau 2006 argued that although there is no hard proof of soft tissue dystocia, it must exist because there is an increase in cesareans due to prolonged labor in obese women compared to average-sized women with similarly-sized babies. 

However, I will point out again that a higher rate of malpositioned babies among women of size could also explain their longer labors and increased rate of cesareans due to labor dystocia.

Babies who face their mothers' tummies (occiput posterior) don't fit as easily through the pelvis, present with a larger head diameter, and often experience long, slow, hard labors.  Research clearly shows that posterior babies have longer and slower labors and have a much higher cesarean rate than anterior babies. 

Although the subject needs further study, some research has found a higher rate of malpositioned babies in "obese" women, and very old obstetric research also often notes in passing a higher rate of occiput posterior and other malpositions in women of size as well.

And anecdotally, women of size often do seem to have more malpositions, especially occiput posterior, many of which result in cesareans.

Many of these fat women have been told they had cesareans because of their "fat vagina" or "too small" pelvis.  Yet if you read their stories carefully, they had all the signs and symptoms of a malpositioned baby instead. 

Furthermore, many women who had cesareans for "fat vaginas" went on to have subsequent vaginal births with babies that were even larger than their cesarean babies....without losing weight first. This would be impossible if the problem really were a "fat vagina." 

The key was having a well-positioned baby, not losing weight or reducing maternal pelvic fat deposits. 

Another problem with the concept of the "fat vagina" is the inconsistency with which this diagnosis is applied. If a ~275 lb. woman (like my friend from ICAN) is told that her vagina is "too fat" and prevented her baby from getting out, then it follows that a 350 lb. woman should not be able to birth a similarly-sized baby vaginally. Yet we know that women of that size can and do have vaginal births. I have birth stories on my website of vaginal births to women at 300, 350, and 400 lbs.  Yes, women of this size have a high cesarean rate because they are almost never given a real chance to actually have a vaginal birth.....but it can happen when they are given a realistic chance.

If fat vaginas truly prevented vaginal birth as much as some providers think they do, there would be NO vaginal birthers above a certain size. Sure, vaginal birth is always a combo of factors, including pelvic size/shape, the baby's size and position, (passenger, powers, position, etc.), so some variability in who gives birth vaginally is logical, but if soft tissue dystocia were a really significant factor, really supersized women would never birth vaginally.  Yet many can and do, if they have a well-positioned baby and are given a realistic chance.

In my opinion, the real issue behind a higher rate of "dystocia" cesareans in women of size is probably fetal position, not fat vaginas. 

However, because doctors are trained to blame obesity as the go-to diagnosis when they don't have another explanation, soft tissue dystocia gets blamed for "blocking" the baby's way out. 

But that's just lazy thinking, not actual proof of soft tissue dystocia.

What About Shoulder Dystocia?

Another fear that many doctors and midwives have is that extra soft tissue in a fat woman's vagina might cause such a tight fit for the baby that the baby's shoulders will get stuck ("shoulder dystocia"), which can be a true obstetric emergency.

This fear seems borne out by studies which have shown higher rates of shoulder dystocia in "obese" women. Yet many of these studies did not control for other factors, like macrosomia, diabetes, forceps/vacuum extractor, or induction, all of which increase the risk for shoulder dystocia, and most of which occur at higher rates in women of size. 

It's important to note that other studies have found that obesity is not a risk factor for shoulder dystocia when these other factors are controlled for. 

Furthermore, it is not extra fat crowding the vaginal walls that causes shoulder dystocia. Rather, shoulder dystocia is caused by obstruction by the bony pelvis, not soft tissues. A complex interplay of factors results in shoulder dystocia, including fetal position, maternal position and mobility, pelvic shape, induction, operative delivery, diabetes, and macrosomia. 

But justified or not, fear that "extra" soft tissue will cause shoulder dystocia is a big contributor to the high planned cesarean rate and early induction rate in women of size. 

But What If Soft Tissue Dystocia is Real?

Frankly, soft tissue dystocia as a concept has not been proven at all, but some care providers believe in it with all their heart and refuse to be dissuaded from the possibility, pointing out that it hasn't been disproven conclusively either.  That's a fair point.

To these providers I would argue that IF soft tissue dystocia were indeed real, then it is vital to change how most providers manage the labors of women of size in order to minimize its theoretical impact.

The typical way the labors of many "obese" women is managed often includes inducing early, breaking the bag of waters early, strongly encouraging early placement of an epidural "just in case," strictly limiting mobility, and using semi-sitting or lying back positions for pushing. Yet these measures often limit the amount of pelvic space the baby has to fit through.

If a bunch of extra fat is supposedly crowding things already, these restrictive protocols just make things worse.

IF soft tissue dystocia were real, mobility in labor would be even more important to women of size because it opens up the pelvic dimensions and gives "obese" women the best possible chance to help that baby fit through. Yet "obese" women have the most restrictions on their mobility in labor and are the least encouraged to try alternative positions for birth.

If a provider truly believes that soft tissue dystocia might be real, then the answer is not to pre-emptively induce or section women of size, but to give them every chance at creating more space in the pelvis. 

This means not having her in the usual lying back/semi-sitting position, which puts pressure on the tailbone and presses it into the pelvic cavity, reducing the space available. 

This means not requiring/pressuring her for an early epidural (as many practices encourage with women of size), so that she can move freely during labor and encourage her baby to be in a good position for birth. 

It means not breaking her waters early in labor, so the baby has the watery cushion to help it move into an optimal position. 

It means letting her stay upright as much as possible, so she can use gravity to help bring that baby down and press it through those supposedly fat-crowded walls. 

It means letting her push in whatever position feels comfortable to her, encouraging her to stay mobile, and letting her utilize things that will help her stay mobile more easily (a labor tub, a dangling support or trapeze bar, a squat bar, etc.).

Personally, I don't believe that soft tissue dystocia is clinically relevant, but if you are a provider and you firmly believe in its existence, follow that to its logical conclusion and utilize labor protocols that help that woman maximize her pelvic space, not inhibit it via restrictive protocols. 

Conclusion

Soft tissue dystocia is a belief that is near and dear to many doctors' hearts (and sadly, even to some midwives' hearts). Yet despite no research to support it, it as taught as if it is fact. 

At this point, soft tissue dystocia is NOT fact.  It has not been proven at all, and remains highly speculative as a possible cause of labor issues.

Furthermore, many women of size who have had their cesareans blamed on "fat vaginas" have gone on to have vaginal births in later births----without having lost weight first.  If soft tissue dystocia were really the cause of their cesareans, this would not have been possible. The issue for them was fetal position, not maternal soft tissue. 

The "morbidly obese" friend of mine who was told that her "fat vagina" was the cause of her cesarean?  She has since gone on to have TWO vaginal births.....at the same maternal weight, with similarly-sized babies.  So much for her "fat vagina" preventing the baby from coming out! 

And then there's the commenter on my blog who had a similar experience: 

I was told by my OB, while on the operating table and again at my 6 week check, that 'my vagina was too fat to birth a baby naturally'. Had a VBAC 3 years later though!

[Comment on 10-12-10, on Prenatal Weight Gain: The Importance of Study Design.]

Far too often, "fat vagina" is just a convenient excuse for lazy thinking, a handy scapegoat for the high cesarean rate in women of size, and a convenient excuse for blocking access to VBAC in yet another group.

And unfortunately, it prevents caregivers from examining their own care practices and how iatrogenic influences like weight bias, induction, fear of macrosomia, restrictive protocols, "failure to wait" and fetal position issues are the real factors driving the cesarean rate for women of size.  

Healthy Birth Practices: Let Labor Begin On Its Own

In the next few weeks, we will be looking at the Six Lamaze Healthy Birth Practices and why they are important for promoting healthy births.

We will also see how many of these optimal birth practices are actively discouraged for "obese" women during labor and how this impacts their cesarean rate, birth experiences, and breastfeeding.

The first Healthy Birth Practice is probably the most important one of all:

1. Let labor begin on its own

Ironically, this is one of the most often ignored in current obstetric practice with women of size.

General Risks of Induced Labor

Today, more and more women of every size are having their labors induced. This is risky because when labor is started artificially, it means that the baby and mother are not truly ready for birth yet, and complications can ensue. (Study references beyond those already linked to can be found in the Healthy Birth Practice Paper, here.)

Inducing labor, especially in first-time mothers, tends to increase the risk for cesareans. The mother's body may not be ready to dilate fully and she may therefore end up with a cesarean for "Failure To Progress" (FTP). Or the baby may not yet be in the easiest position for birth and the mother may end up with a cesarean for "Cephalo-Pelvic Disproportion" (CPD, or baby didn't fit right).

Inducing labor also increases the risks for vacuum- and forceps-assisted births. This is often because the baby had not yet moved into an optimal position for birth, or because the mother has an epidural and the baby cannot rotate easily through the pelvis. Help may be needed to get the baby out, but this help often also comes with the price of an episiotomy (cutting to widen the vaginal opening).

Inducing labor early can also result in a "near-term" preemie which may experience problems with jaundice, low blood sugar, and difficulty breastfeeding. Even close to term, the baby's lungs may not be completely ready to breathe yet on the outside, and as a result, the baby may experience respiratory distress after the birth and end up in the Neonatal Intensive Care Unit (NICU).

Induction also carries direct risks to both mother and baby in other ways as well. For example, the induced mother's uterus may experience "tachysystole" (hyperstimulation) and labor may need to be stopped before it results in uterine rupture (a tear in the uterus) or placental abruption (the placenta pulling away from the uterus prematurely). Induction is also associated with amniotic fluid embolism, and while rare, this can result in death to the mother.

Furthermore, although synthetic oxytocin (a.k.a. "pitocin" or "syntocinon") is chemically the same as the mother's own oxytocin, it does not act exactly the same in the body during labor. As Dr. Sarah Buckley notes:

Synthetic oxytocin administered in labor does not act like the body’s own oxytocin. First, syntocinon-induced contractions are different from natural contractions, and these differences can cause a reduced blood flow to the baby. For example, waves can occur almost on top of each other when too high a dose of synthetic oxytocin is given, and it also causes the resting tone of the uterus to increase.

Second, oxytocin, synthetic or not, cannot cross from the body to the brain through the blood-brain barrier. This means that syntocinon, introduced into the body by injection or drip, does not act as the hormone of love. However, it does provide the hormonal system with negative feedback—that is, oxytocin receptors in the laboring woman’s body detect high levels of oxytocin and signal the brain to reduce production. We know that women with syntocinon infusions are at higher risk of bleeding after the birth, because their own oxytocin production has been shut down.

Induction also carries risks to the baby. Induction often involves breaking the mother's amniotic sac manually at some point during labor, which carries the risk of umbilical cord prolapse. Although rare, this can cause brain damage or even death to the baby and necessitates an immediate emergency cesarean.

The use of labor induction drugs often causes contractions that are harder and closer together than in spontaneous labor, and as a result, baby is not given as much time to recover its oxygenation between contractions. This lack of recovery time can cause fetal distress. This is why babies must be continuously monitored during an induced or augmented labor.

These harder, longer, and more intense contractions often also result in a higher use of pain medications by the mother. There is nothing wrong with choosing to receive pain medications if you need them (and it's great that women have the choice available if needed), but it's important to remember that these are strong medications and they do carry real risks to both mother and baby.

While many women go into labor intending to "go natural" (without pain medications), this becomes very difficult if the mother is induced. Although not impossible, it's a rare woman who is able to complete a whole induced labor and birth without at least some pain medications.

Furthermore, induction increases the risks of further interventions becoming "needed," all of which have their own risks. And induction decreases the mother's ability to utilize the other Health Birth Practices such as move freely, be upright for pushing, etc. From the Let Labor Begin On Its Own practice paper:

In addition to an increased risk for mild prematurity and cesarean surgery, induced labor often creates the need for more medical interventions.

In most cases, if you are induced, you will need an IV and continuous electronic fetal heart rate monitoring. In many settings, you must stay in bed or very close to the bed. As a result, you may be unable to walk freely or change positions in response to your labor contractions, possibly slowing the progress of your labor. You may be unable to take advantage of a soothing tub bath or a warm shower to ease the pain of your labor contractions. Artificially induced contractions often peak sooner and remain intense longer than natural contractions, increasing your need for pain medications.

Labor induction leads to a cascade of interventions, which often result in cesarean surgery.

Induction of labor is far from the benign and minimally risky option that many doctors portray it to be. It has real risks, and in many cases these risks are underplayed.

Sometimes induction of labor is truly needed, and as with cesareans, we can be glad that it is available when needed. However, also as with cesareans, its casual overuse without sufficient consideration about possible risks may result in significant harm.

The Epidemic of Induction in "Obese" Women

Research (insert major-league sanity watchers points if you read these studies!) consistently shows that fat women have higher rates of induction than their average-sized or underweight peers. Yet few studies connect the dots between an elevated rate of induction and a higher cesarean rate in this group.

Michlin 2000 found an induction rate of 20.4% in "obese" mothers, vs. an induction rate of 10.2% in "normal weight" mothers.

Graves 2006 found an induction rate of 33.7% in "obese" women (BMI greater than 29), versus 19.2% in "normal" weight women (BMI 19.8-26 in this study), or 12.6% in underweight women (BMI less than 19.8).

Numerous other studies have also found an increased rate of induction among "obese" women.

Sometimes the higher rate of induction in "obese" women is because they have higher rate of medical complications like pre-eclampsia (blood pressure issues), where getting the baby out sooner may be important. In these cases, a higher rate of induction could be justified.

However, research also shows that even when there are no medical complications, "obese" women are induced at a higher rate than average-sized women.

For example, Usha Kiran 2005 studied 677 "obese" (BMI greater than 30) women in Wales with no complications. They still found a higher induction rate of 36% in "obese" women, compared to a 25.5% induction rate in the control group (BMI 20-30).

So the story of high induction rates goes well beyond complication rates. This raises the question: Why are "obese" women induced at such high rates?

The answer is that there are many factors in this trend.

Some of it is fear. The hyperbole about risk in obesity and pregnancy has created such a state of anxiety that many practitioners assume that inducing labor earlier is better, ostensibly before complications can occur. Alas, there is little recognition that they may actually introduce more risks than they alleviate by inducing early, and little work has been done to challenge or affirm whether inducing early helps or harms women of size.

Another factor may be biological differences. For example, fat women tend to have longer gestations and more "postdates" pregnancies. This may be tied to the fact that many women of size have longer menstrual cycles (which, unless greatly divergent, is rarely adjusted for in pregnancy dating). In addition, the definition of "postdates" has shortened in many studies, making even more fat women fall outside the narrowing definition of normal. This may have the net affect of raising the induction rates in women of size even higher.

In fact, in two of the studies above with high "obese" induction rates (Graves 2006 and Usha Kiran 2005), postdates pregnancies were listed as a major cause of the high induction rates.

In Usha Kiran 2005, 41% of the "obese" women had "post-dates" pregnancies, which this study defined as greater than 41 weeks. This poses the question....if nearly half of the "obese" women have "postdates" pregnancies, doesn't this suggest that something about the definition of postdates or the dating of these women is wrong?

And in fact, the Usha Kiran study also shows how strongly induction negatively influenced outcomes in the "obese" group. Tellingly, the cesarean rate in the "obese" group with spontaneous labor was 19%, whereas it was 41% in the induced group. Nearly half the "obese" women who were induced ended up with a cesarean, but only one-fifth of the ones with spontaneous labor had a cesarean.

The study further noted that the induction of labor was the start of many problems for the "obese" women in the group, including more blood loss, more UTIs, more babies in the NICU, more feeding difficulties, more neonatal trauma, etc.

The high rate of induction in women of size is one of the strongest factors in the high rate of cesareans in women of size, and may factor into other negative outcomes in this group....yet there is very little recognition of this fact among medical professionals.

Induction for Macrosomia

The strongest factor by far in the high induction rate of "obese" women is the fear of a big baby. I can't stress this strongly enough. In my opinion, fear of big babies is what's really driving the high cesarean rate in women of size.

Doctors and many midwives have been trained to think that most big mamas produce big, "overly fat" babies, and therefore are strongly at risk for shoulder dystocia (where the baby's shoulders get stuck and baby may be injured).

Because shoulder dystocia injury is one of the main causes of practitioners being sued, many practice defensive medicine. With macrosomia (big baby), this means many induce labor early for women suspected of having a big baby. They reason that bringing labor on a bit early, while the baby is smaller, may make it easier for the baby to be born without shoulder dystocia.

Now, this sounds logical--induce early while the baby is small to increase the chances of it coming out vaginallyand safely--but unfortunately, research shows exactly the opposite effect. Studies actually show that inducing for a big baby often worsens outcome.

The Healthy Birth Practices handout on "Let Labor Begin on Its Own" makes a point of debunking the common idea that it's important to induce early when a big baby is suspected.

It is also important to know that suspecting a large or very large baby is not a medical reason for induction. Studies have shown that inducing labor for macrosomia (large baby) almost doubles the risk of having cesarean surgery without improving the outcome for the baby (Horrigan, 2001; Leaphart, Meyer, & Capeless, 1997; Sadeh-Mestechkin et al., 2008; Sanchez-Ramos, Bernstein, & Kaunitz, 2002).

Furthermore, it is very difficult to know how big your baby is until he is born. Ultrasound is not good at predicting macrosomic (very large) babies. According to ACOG (2009), an ultrasound estimate of the baby’s weight is imprecise, with a variability of 16% to 20%.

Simhayoff 2004 found inducing labor in women with macrosomic babies increased the cesarean rate, not decreased it. The c-section rate in the induced group was 17.8%, vs. 11.9% in the group with spontaneous labor.

Leaphart 1997 found that inducing for macrosomia more than doubled the cesarean rates, from 17% to 36%, while not significantly reducing shoulder dystocia rates.

Combs 1993 found that inducing for macrosomia increased the cesarean rate from 31% to 57%, and there was twice as much shoulder dystocia in the induced group.

Navti 2007 studied the management of women with macrosomic babies at their institution in the U.K. They concluded that "induction for fetal macrosomia alone did not improve outcome but was associated with a significantly higher emergency caesarean section rate and should therefore be discouraged."

Another troubling aspect of induction for suspected macrosomia is the inaccuracy of estimating fetal size. Research shows that ultrasounds for fetal size are particularly poor at predicting macrosomic babies accurately. Furthermore, it also shows that the mere suspicion of macrosomia often raises the cesarean rate significantly.

Weiner 2002 found that merely estimating the baby to be big--even when it wasn't big at all--doubled the cesarean rate.

When the baby is suspected to be large, there may be a lower threshold for diagnosing labor troubles and proceeding to a cesarean. Blackwell 2009 found a higher cesarean rate for labor arrest (34.8%) in those mothers in whom fetal weight was overestimated, vs. those for whom fetal weight was not overestimated (13.3%), despite similar actual labor lengths. This shows that when a big baby is suspected, practitioners expect labor to be abnormal and are quicker to order a cesarean.

Sadeh-Mestechkin et al., 2008, found that when macrosomia was suspected and the baby really was big, the induction rate was much higher (42.1%) than when the baby really was macrosomic but nobody suspected that (13.6%). As a result, the c-section rate was much higher in the suspected macrosomia group (57.1%!) than in the non-suspected macrosomia group (16.7%), even though babies in both groups were actually big.

Let me repeat that. Both sets of babies were big, but the suspicion of macrosomia raised the c-section rate from 16.7% to a whopping 57.1%. In other words, the size of the baby itself had much less impact on the cesarean rate than the perception that the baby might be big and the resulting management of labor.

A higher cesarean rate might be acceptable if induction of labor for macrosomia actually prevented shoulder dystocia and related birth injuries, but research shows that it does not. In fact, one extremely large study (Christoffersson 2003) shows that induction of labor (especially when associated with epidurals and vacuum/forceps delivery, as induction of labor often is) actually increases the risk for shoulder dystocia.

Gherman 2006 reviewed the topic of preventing shoulder dystocia and noted:

There is a significantly increased risk of shoulder dystocia as birth weight linearly increases. From a prospective point of view, however, prepregnancy and antepartum risk factors have exceedingly poor predictive value for the prediction of shoulder dystocia. Late pregnancy ultrasound likewise displays low sensitivity, decreasing accuracy with increasing birth weight, and an overall tendency to overestimate the birth weight. Induction of labor for suspected fetal macrosomia has not been shown to alter the incidence of shoulder dystocia among nondiabetic patients.

Sadeh-Mestechkin et al., 2008, also concluded, "Our ability to predict macrosomia is poor. Our management policy of suspected macrosomic pregnancies raises induction of labor and cesarean delivery rates without improving maternal or fetal outcome."

Although research continues to pour in, showing that induction for macrosomia worsens outcomes and that even estimation of fetal weight is harmful, providers continue to resist changing their practice patterns. Ultrasounds to estimate fetal weight remain routine at the end of pregnancy, and induction for suspected macrosomia remains very common.

Induction for Macrosomia: Still Common Practice with Women of Size

Despite all the evidence that estimating fetal weight and inducing early for macrosomia actually worsens outcomes, it is still routine practice to do these things with "obese" women in particular. Very few practitioners question doing it.

Many providers cite shoulder dystocia as the reason for doing so, believing that fat women are at particularly high risk for shoulder dystocia, while others believe that inducing early will increase a fat woman's chance of having a vaginal birth. But does research really bear out these assumptions?

It is true that "obese" women, on average, do have bigger babies than women of average size. However, most fat women do not have macrosomic babies. Michlin 2000, discussed above in the induction section, found that "obese" women had a macrosomia rate of 16.8% (vs. 8.4% in the average-sized women), and this is similar to rates in other studies as well. Although the rate is higher in the "obese" group, it should be noted that 83% of the "obese" group did not have big babies.

The vast majority of "obese" women do not have macrosomic babies, yet the majority are treated as if they will have huge babies, and as if shoulder dystocia is inevitable in this group as well.

In addition, many women who do have macrosomic babies have vaginal births anyhow. The afore-mentioned Navti 2007 study found that 83% of women who had babies around 10 pounds or more were able to have vaginal births. Even very big babies can often be born vaginally, given time, patience, sufficient mobility, and a calm caregiver.

Furthermore, studies that adequately control for other factors such as diabetes status, macrosomia, and induction status have found that obesity itself is NOT an additional risk factor for shoulder dystocia. (Robinson 2003, Neumann 2001, Poggi 2003)

Robinson's study concluded:

Demonstrating a lack of independent association between maternal obesity and shoulder dystocia may encourage clinicians to allow nondiabetic obese patients an adequate trial of labor rather than to choose to proceed to cesarean delivery earlier because of the fear of shoulder dystocia. This may decrease the incidence of cesarean delivery and the morbidity associated with it in the obese patient population.

Unfortunately, most clinicians have not taken this advice to heart. Although the reasons for induction may get coded differently in official documents, many fat women anecdotally report that fear of a big baby or shoulder dystocia is one of the reasons most frequently used to pressure them into induction of labor.

A policy of inducing most fat women because of the fear of a big baby means that most will be induced unnecessarily, as most will not have big babies anyhow. It disproportionately and unnecessarily exposes these women (and their babies) to all the risks of induction listed in the first section. Furthermore, since inducing for macrosomia usually increases the cesarean rate, it disproportionately increases the cesarean rate in women of size, exposing them to those risks as well.

Few studies have directly examined the question of whether inducing for macrosomia in "obese" women improves or worsens outcomes, but it is reasonable to suspect that it worsens outcomes, as it does in other women.

In what studies we do have, Graves 2006 found that the combination of obesity, macrosomia, nulliparity (first-time mom), and induction doubled the risk for cesarean section. And remember, Usha Kiran 2005 found a c-section rate of 19% in spontaneous labor vs. 41% in induced labor. They also found that induction was the beginning of many of the negative outcomes found in women of size.

Unfortunately, the authors did not follow through to the logical conclusion and question whether they should be inducing so liberally. Instead they conveniently just blamed obesity for the cesarean rate.

Conclusion and Video Link

If you want to read further about the risks of inductions and why spontaneous labor is better for mothers and babies in most cases, read the accompanying Healthy Birth Practices handouts that explain and cite research to support their conclusions. See also the video link below.

If you are a woman of size and want to lessen your risk for cesareans, ask your caregivers an open-ended question about what they would do if they suspected you were carrying a big baby. Then just let them talk and see what they say.

If they mention decision-making based on ultrasound for estimated fetal weight, inducing early for a smaller baby, or scheduling a planned cesarean if baby is over 9 lbs., then you know this is not an evidence-based provider.

Rather, it is one who makes decisions out of fear, has many negative assumptions about size, and who is mainly motivated by litigation concerns, rather than what's best for you and your baby. With this kind of provider, you are likely to end up with lots of interventions and a strong possibility of a cesarean. Whether that's acceptable is up to you...just go in with your eyes open and knowing the risks.

Either way, be sure to watch the video below.




*The topic of induction for suspected macrosomia is of particular interest to me, since 3 of my 4 children were "encouraged" to come early because of fears of macrosomia due to my size. 2 of these "encouragements" resulted in cesareans.

If you are a woman who was encouraged to have an early induction or planned cesarean because of suspected fetal macrosomia, be sure to briefly let us in on your story in the Comments section.