Obese Patients Undertreated for Infection in the Emergency Room

The following study shows just how badly obese patients are underdosed with antibiotics in the Emergency Room (E.R.).

Terri of the FattiesUnited blog brought this study to the attention of the fatosphere briefly several months ago, just as I was about to write a post about this study too, so I put the post on the back burner.

However, in writing an upcoming post on treating Surgical Site Infections in people of size, I came across the study again and decided it was important enough to be highlighted once more.  Any of us can end in the Emergency Room at any time, regardless of size.  But those of us who are fat need to be aware of the possibility of underdosing and to be able to advocate for ourselves as needed.  Perhaps sharing the full details of this study will help in that process.

In this study, the initial antibiotic dosages of "morbidly obese" folks (BMI over 40) who visited the E.R. and were prescribed 3 common antibiotics were analyzed retrospectively for a 3-month period.  The doses were compared with internal hospital guidelines for antibiotic dose adjustments for obese folks.

Less than 5% of morbidly obese patients were given the correct antibiotic dose for their weight.

That's right, more than 95% of high BMI patients were underdosed with antibiotics, putting them at significant risk for serious complications.

The study notes:

Although there are guidelines for dose adjustments for many of the antibiotics commonly used in the emergency department (ED), they are seldom used...Underdosing antimicrobials presents risk of treatment failure and may promote antimicrobial resistance. Education is necessary to improve early antibiotic administration to obese patients.

Study Details

This study was done as a quality improvement review at an urban Level I trauma center with an emergency medicine residency.

In the study, pharmacy records were collected retrospectively to identify the initial dose of cefazolin, cefepime, or ciproflaxin given in the E.R. to patients with a BMI greater than 40 and who weighed more than 100 kg.

These three drugs were chosen because they are used so frequently and because, unlike many antibiotics, there are readily-available guidelines for dosing obese folks without having to do a bunch of complicated extra calculations first.  The guidelines are distributed in a handbook each year to every resident and are also always available on the hospital's internal website, so there was no excuse for not knowing or not checking the recommended dosages.

The study looked at only the initial dose given (and to be fair, any additional dose within 4 hours, as sometimes doctors self-correct dosing when they have a chance to look up the guidelines).

This attention to the initial dose is important because the first dose of antibiotics is the most important in knocking down an infection.  According to the study, the effectiveness of this class of antibiotics (cephalosporins) is proportional to the amount of time kept above the Minimum Inhibitory Concentration (MIC). If the initial dose does not achieve MIC, then the patient may develop resistance to the antibiotics, not to mention serious complications, longer hospital stays, or even death.

In the study, there were 1,910 orders that fit the criteria in the 3-month study period. Of these, only 4.6% of the antibiotic orders were dosed appropriately for morbidly obese patients.

For cefepime, the adherence rate was 8%.  For cefazolin, the adherence rate was 3%, and for ciproflaxin the adherence rate was only 1.2%.

This is an appallingly poor adherence rate to readily-available, simple dosing guidelines. The study notes this and emphasizes how important it is to ensure adequate dosing in morbidly obese patients:

Attaining therapeutic dosing in [morbidly obese] patients is especially important.  Obese patients present a greater risk of infection and a higher morbidity and mortality associated with infection than does the general population.  Subtherapeutic dosing increases the risk of treatment failure, unnecessary escalation to broader-spectrum antibiotics, and selection of resistant pathogens...Because early antibiotic administration reduces mortality in life-threatening infections, meeting proper dosing guidelines in the [Emergency Department] should be of the highest priority.

The authors go on to cite another study which found that when the perioperative dose of cefazolin was doubled to 2g in obese patients, the postoperative infection rate dropped from 16.5% to 5.6%.  This shows that increased dosages of this antibiotic in heavier patients do result in improved outcomes.

Interestingly, there is recent data (Pevzner 2011) on cesareans in morbidly obese patients suggesting that even a doubled, 2g dose of cefazolin may not be enough, and that further research is needed to figure out the most effective perioperative dose in this group.  What implications this has for E.R. usage is unknown but suggests doses bigger than 2g may also need to be considered. Research needs to be done to find the optimal dose for each size.

Concluding Thoughts

Sooner or later, people of every size end up in the E.R., especially as they age.  Different populations present different care challenges; obese people present a unique subset whose care challenges are often under-recognized and under-addressed.

Bottom line, the best care protocols for obese people are yet to be determined because research on the topic has been woefully inadequate.  Furthermore, even when the best care protocols are known, they are often not followed by medical personnel.  Therefore, it is critical as people of size that we know about key care issues in our own care and how to advocate for ourselves when we interact with medical personnel.  

One of the most understudied areas in the care of obese patients is optimal medication dosage.  Research shows that obese patients (and especially morbidly obese patients) are often dosed inappropriately with a variety of drugs, from chemotherapy to anti-coagulants to antibiotics, and this may be correlated to poorer outcomes among these groups.

Clearly, it is imperative that more research and physician education be done on appropriate medication dosage for people of size as quickly as possible.

In this study, only initial antibiotic dosing at the Emergency Room was examined, using only common antibiotics with easily-available dose adjustments.  Even so, less than 5% of the morbidly obese patients were given dosages that adhered to the internal guidelines of the hospital.

One has to wonder how adequate the dosing was in very fat patients for the rest of their hospital stays and how that impacted their outcomes.

Ironically, this was in a hospital that is a regional referral center for fat patients and is recognized as a Bariatric Surgery "Center of Excellence" (ugh).  That makes the findings even more alarming.

If a teaching hospital that specializes in the treatment of very fat people doesn't routinely use the correct antibiotic dosing in their E.R., what are the underdosing rates in community hospitals that don't specialize in fat patients at all?

This study has lessons both for people of size and for the medical community.

Fat people should know that if they end up in the E.R. for an infection of some sort, they need to ask their physician to check into adjusted antibiotic doses for weight.  Not every type of antibiotic needs dose adjustment, mind ─ it all depends on how they are designed to work in the body.  But this study indicates that you may really have to push your physician to find out about dose adjustments and to use them when they are indicated.

Most physicians truly want their patients to get better, so it's really OK to ask about whether weight-based dosing is needed for you. However, don't be afraid to ask for a consult with an infections specialist if you feel your E.R. doctor is not attentive to your concerns, or to involve the hospital's Patient Advocate in getting your concerns heard.  There are measures in place to help patients advocate for their own needs, and you don't have to go it alone.

But the first step is self-education, to know where the potential issues may lie, to know to ask questions about dosages, and to feel empowered enough to do so.

For medical professionals, the associated lesson is that they must aggressively press for better research on optimal medication dosage in obese patients, and to continue to push for more physician education and accountability on these matters.

*Next post.....other ways to improve response to infections in people of size, including IV antibiotics, more frequent dosings, and topical infusions.



References

Am J Emerg Med. 2011 Dec 12. Underdosing of common antibiotics for obese patients in the ED. Roe JL, Fuentes JM, Mullins ME.  PMID: 22169576

BACKGROUND: Obesity is a growing problem in the United States. Obesity alters the pharmacokinetic profiles of various drugs. Although there are guidelines for dose adjustments for many of the antibiotics commonly used in the emergency department (ED), they are seldom used. METHODS: This is an institutional review board-approved retrospective study at an American Society of Metabolic and Bariatric Surgery Center of Excellence and a level I trauma center with annual ED volumes of more than 80 000 visits. Data were retrospectively collected from ED pharmacy records during a 3-month period in 2008. Any first dose of cefepime, cefazolin, or ciprofloxacin administered in our ED to a patient recorded as both more than 100 kg and with a body mass index greater than 40 kg/m(2) was compared with our hospital guidelines and found to either adhere or not adhere to those guidelines. RESULTS: There were 1910 orders found to meet the study criteria: 775 orders for cefepime, 625 orders for cefazolin, and 510 orders for ciprofloxacin. Adherence rates for first dose of cefepime, cefazolin, and ciprofloxacin administered, respectively, were 8.0%, 3.0%, and 1.2%. CONCLUSION: Emergency physicians frequently underdose cefepime, cefazolin, and ciprofloxacin in obese patients. Underdosing antimicrobials presents risk of treatment failure and may promote antimicrobial resistance. Education is necessary to improve early antibiotic administration to obese patients.

Surgery. 2004 Oct;136(4):738-47. Perioperative antibiotic prophylaxis in the gastric bypass patient: do we achieve therapeutic levels? Edmiston CE, et al.  PMID: 15467657

BACKGROUND: Perioperative surgical antibiotic prophylaxis requires that therapeutically effective drug concentrations be present in the tissues. METHODS: Patients undergoing Roux-en-Y gastric bypass for morbid obesity were given 2 g cefazolin preoperatively, followed by a second dose at 3 hours. Thirty-eight patients were each assigned to 1 of 3 body mass index (BMI) groups: (A) BMI=40-49 (N = 17); (B) BMI=50-59 (N=11); (C) BMI > or= 60 (N=10). Multiple timed serum (baseline; incision, 15, 30, 60 minutes; prior to second prophylactic dose; and closure) and tissue (skin, subcutaneous fat, and omentum) specimens were collected and cefazolin concentration analyzed by microbiological assay. RESULTS: ...Over 90% of serum samples exhibited therapeutic concentrations covering 53.8% of gram-positive and 78.6% of gram-negative surgical pathogens. However, therapeutic tissue levels were achieved in only 48.1%, 28.6%, and 10.2% of groups A, B, and C, respectively. CONCLUSIONS: Pharmacokinetic analysis suggests that present dosing strategies may fail to provide adequate perioperative prophylaxis in gastric bypass patients.

Obstet Gynecol. 2011 Apr;117(4):877-82. Effects of maternal obesity on tissue concentrations of prophylactic cefazolin during cesarean delivery. Pevzner L, et al.  PMID: 21422859

OBJECTIVE: To estimate the adequacy of antimicrobial activity of preoperative antibiotics at the time of cesarean delivery as a function of maternal obesity. 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. Antibiotic concentrations from adipose samples, collected after skin incision and before skin closure, along with myometrial and serum samples, were analyzed with microbiological agar diffusion assay. 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.

thyroid updates

So I went to my family doctor recently for a check-up and my thyroid bloodwork.

The bad news is that my thyroid is out of whack again, and the even worse news is that Armour thyroid is no longer producing the natural T3 medications that are so much more effective for me.

What the heck? What I am supposed to do for meds now?

Another frustrating thing is that if your TSH is higher than normal for you....yet still within the range of "normal" the docs go by.....they won't change your prescription.

My NP (nurse-practitioner) listens better than most, and she knows I have a long history of trying to establish the best TSH level for me. She knows I feel best when my TSH is under 1.5 (preferably more like 1.0), and that if it gets up around 2 or more, I start experiencing more symptoms like fatigue, cold, and weight gain...all of which I've been having again.

My level this past test was 2.4, but her hands are tied. She can't up my prescription when my levels are still in the "normal" range.....even though they are not in the range that is optimal for me and which keeps me from gaining weight.

And furthermore, if I stay in her care, I have to be on all levothyroxin, a T4-only medicine, instead of on the combo of T4 and T3 etc. meds that come in Armour. AND in effect I would be getting an even lower dose, because she didn't raise my levothyroxine dose to compensate for the loss of the Armour because my TSH is still within "normal."

Augh. I am so frustrated with this. She really is better than most docs I have had, but it frustrates me no end that they are required to rely on this TSH test so heavily and completely discount symptoms as a guide. My T4 and T3 levels are "normal," but just barely....but that doesn't matter, because they ARE normal, and so is the TSH. Doesn't matter if you are experiencing symptoms and you've experienced a deterioration trend in your levels....you are either normal or not, and that's that.

Here we go again with the binary approach in medicine. You are either normal or abnormal and there's nothing in between. If the cutoff is 140 (pulling a number out of the air for demo purposes), you are normal at 141 and no changes need be made, but you are abnormal at 139 and changes should be made. There's only two points difference, for crying out loud! But one is above an arbitrary cutoff and one is below it, so it doesn't matter.

My test results are clearly trending negatively and I'm experiencing more symptoms.....but because I'm still marginally in the normal range, they aren't going to change my dosage.

This frustrates me so much. If they care so much about my weight (she suggested briefly that perhaps we might think about "carving off a few pounds".....ugh, I am NOT a turkey), then they ought to be LISTENING to me about the one thing which DOES help with my weight.

I don't really lose much weight when my thyroid levels are more well-regulated, but I stop gaining and am more easily able to keep my weight steady. Isn't that a worthy goal? The last thing she wants is for me to gain more weight....but she won't do the one thing which is most effective at preventing that.

Now, I'm making her sound like an ogre, which she really is not. She's been more sympathetic and listened more than a lot of docs I have had, and she's a genuinely nice person. I was unhappy about her bringing up the weight loss thing, but she backed off quickly when I reminded her that my history showed that this was the fastest route for me to actually gain weight and if we wanted to avoid me that, dieting was the worst thing I could be considering. She acknowledged that I was the person who knew my own history best and what was most/least likely to work for my body. So that was something, anyhow.

Also to her credit, she knows I feel strongly about the whole Armour thyroid thing and about titrating my TSH levels more carefully. She said HER hands were tied, but suggested that I might consider going to see a local naturopath for further consultation. There are some alternatives for Armour out there (according to the thyroid websites) but she is not allowed to prescribe them; she thought perhaps the naturopaths might have access to them instead.

So I guess that's what I'm down to. Personally, I'm a bit leery about seeing a naturopath. I think some are okay and have decent training, and I'm okay with considering some alternative modalities of care. I'm not always convinced every alternative modality works, but I'm open to considering some. I figure I can always say no if it sounds too "woo-woo" for me.

[To my surprise, I actually have found a couple of "alternative" modalities -- like chiropractic and acupuncture -- pretty darn useful and effective for me, so I try to at least keep an open mind to considering other forms of "alternative" care.]

On the other hand, I do think there are some nutcase naturopaths out there, and some "alternative" modalities are potentially harmful. Just because one alternative modality works for me doesn't mean they are all going to, nor that they are going to be perfectly safe. And the science part of me squirms a bit when considering some of this stuff. I'd rather have some really good studies showing me what's effective and what's not, what's safe and what's not.

On the other other hand, though, traditional allopathic medicine has been mostly unhelpful for me in dealing with this thyroid stuff, and right now I feel like I'm stuck between a rock and a hard place and don't have many choices left. Stay with my traditional practice and have my thyroid needs undertreated, or go try an alternative practice that might meet my needs better but which might also try to rook me into some bizarro stuff.

After thinking about it, I think I'm going to check out a couple of local naturopaths who are trained in both allopathic and naturopathic medicine and see what they say. I'll be taking along a healthy sense of doubt and ability to say NO, never fear, but I know I need to figure this thyroid thing out better. I know from experience that this thyroid thing is the most important thing to keeping me healthy, so the bottom line is that's just GOT to get addressed better.

Levothyroxine may be the "accepted" med in the allopathic world, but it's not the better med for me, and I know I'm incredibly sensitive to even very small changes in TSH levels. If I have to go to a more "alternative" practitioner to get my needs addressed adequately, then so be it.

I'm just pissed as hell that it's come to this. UGH.

Blood Pressure Cuff Size and Pregnancy

We have been discussing the importance of blood pressure cuff sizes, especially for people of size.

When a too-small cuff is used, blood pressure readings are falsely elevated, sometimes by really sizable amounts. This can lead to medications and interventions that are unnecessary and which can carry significant side effects.

Blood Pressure Cuff Size And Pregnancy

In pregnancy, being vigilant about blood pressure cuff size is even more important, yet using the wrong cuff size (miscuffing) seems even more common in pregnancy.

Anecdotally, fat women report that obstetrics providers often don't carry the full range of cuff sizes and tend to be very cavalier about using the correct size, even more so than non-pregnancy healthcare providers. Even hospital labor wards don't always use the correct size consistently.

Yet it is particularly critical to have an accurate reading of blood pressure in pregnancy due to concerns about hypertensive disorders of pregnancy (like pre-eclampsia), which can be very serious indeed.

Unfortunately, many "obese" women are incorrectly diagnosed with BP issues and subjected to interventions like medications, inductions, and sometimes even unnecessary cesareans because of use of the wrong BP cuff size.

Hypertensive Disorders of Pregnancy/Pre-Eclampsia

Hypertensive Disorders of Pregnancy is one of the most common (and potentially serious) complications of pregnancy.

The term "hypertensive disorders of pregnancy" is an umbrella term used to cover a multitude of blood pressure issues that happen in pregnancy. The terminology for it varies a lot (toxemia, pregnancy-induced hypertension, gestational hypertension, etc.), but that's a discussion for another day. The main issue here is what is commonly known as "pre-eclampsia."

Pre-eclampsia is a rise in blood pressure after 20 weeks gestation in a previously normotensive woman, accompanied by protein in the urine. If it is accompanied by altered lab results (like elevated liver enzymes, uric acid, or low platelets), it becomes really serious.

Severe pre-eclampsia can become truly life-threatening to both mother and baby, sometimes very quickly, and is one of the leading causes of maternal mortality in the world. Thus, doctors take BP issues in pregnancy very seriously indeed, and with good reason.

Outside of pregnancy, a borderline BP number is not pursued that vigorously, but in pregnancy many OBs get nervous about even borderline blood pressures and often will start very aggressive interventions very quickly.

Furthermore, because "obese" women do tend to have higher rates of pre-eclampsia, doctors tend to be even more interventive with women of size at the first suggestion that there might be BP issues.

Therefore, it is extremely important for pregnant women of size to have accurate BP data....yet miscuffing seems to be particularly common in obstetrics.

As a result, pregnant "obese" women need to be particularly vigilant about checking cuff size.

My Anecdotal Stories

Sadly, in 3 out of my 4 pregnancies, miscuffing was an issue at some point or other. That's how common it is, especially in pregnancies of women of size.

Pregnancy #1:

Normally I am quite vigilant about cuff size, and during prenatals I always asked about whether they were using a large cuff.

However, during labor my mind was busy concentrating on coping with contractions and I didn't always ask about cuff size. As a result, at one point the nurse took my BP, became quite alarmed, and was about to initiate several big interventions as a result.

Luckily, I surfaced enough to ask if she had used the large cuff; she said she couldn't find it and it wouldn't make much difference anyhow. We fought about it for quite a while; she was really resistant to getting the larger cuff, and stated strongly that it didn't matter that much and we really needed to start these interventions sooner than later.

I became quite assertive and insisted she go get the large cuff. She huffed out (she was quite mad!) and finally managed to "find" one and re-took my BP.

It was totally normal, as my blood pressure had been throughout all my pregnancy.

During that entire hospital stay, very few staff members understood the importance of a large cuff, and many resisted the idea of getting one. Even when they were willing to get one, they often had trouble finding one, despite being in a hospital setting where they should be plentiful. The resistance to using the correct-sized cuff was considerable, both on an individual and institutional basis.

I managed to stave off the risky interventions that are standard with high blood pressure, but only because I knew about the importance of cuff sizes and was ready to be quite assertive about it.

Pregnancy #2:

In my second pregnancy and labor, I was extremely vigilant about checking on BP cuff size. Because I always asked and because my labor support people asked for me as well when I was preoccupied in labor, I did not have any cuff size issues in this pregnancy......until after the baby was born.

It was only postpartum that the cuff size issue arose....because I was doped out on drugs, post-cesarean, and my support people had gone home to get some sleep.

A nurse came in in the middle of the night to check on me and take my vitals. I was so wiped out and groggy from drugs I didn't bother to ask about cuff size. She took my BP and commented that it was really up.

[It is unusual....but possible....to have normal BP throughout pregnancy and all of labor, and yet still develop pre-eclampsia after the baby is born. That's why they are careful to monitor BP throughout the postpartum period too.]

Fortunately, I surfaced enough to ask whether or not she had used the large cuff. She said no, it was broken, and it didn't really matter that much anyhow. It's a little blurry now but I think she told me I wasn't fat enough for it to be that important anyhow, that the regular cuff fit around my arm just fine.

I think I pointed out that it's not whether the cuff fits or not, it's the size of the cuff/bladder in proportion to your arm size that makes the difference, and that she needed to get the larger cuff.
At that point, she got really snotty. She asked me where I had gotten my medical degree from, implying that she was the medical professional and I was just a lowly ignorant patient, and what did I really know about it anyhow.

[This is typical of medical bullying; when you don't do what they want you to do, they bring out the old "*I* am the medical professional and know more than you," and try to intimidate you into submission.]

I still insisted. She rolled her eyes and snapped that she had so many patients to check on, she couldn't take the time to go get the other cuff, yadda yadda. I still insisted. She was pissed.

Eventually, she did come back with a larger cuff she somehow "managed" to find....and of course, my blood pressure was just fine.

Pregnancy #3:

In this pregnancy, I wanted to avoid the hospital and OBs from the get-go. I chose a homebirth midwife, but she did not own a large BP cuff.

She had not attended many women of my size before so she was not fully familiar with the importance of a large cuff, but she was very open to learning about it from me. We both agreed we needed to have accurate readings to make sure I stayed low-risk enough for a homebirth. I was nearing 40 at that point and the risk for blood pressure issues goes up with age, so even though I'd never had an issue with blood pressure before, we still needed to watch carefully in this pregnancy. After listening to the evidence, she agreed that a larger cuff would be important.

It's been quite a while so I'm a bit hazy on the details of how we got one, but she either bought one or we managed to borrow one. Either way, we managed to find a way to get a large BP cuff so we could have accurate readings.

Fortunately, my BP stayed normal throughout the pregnancy, despite my age. But if I had not been so familiar with cuff size issues, she would not have known that it was so important for someone of my size and I probably would have gotten risked out for no good reason. Luckily, she was open to learning about it.

I did transfer to the hospital during that labor and had my VBAC in the hospital after all. Fortunately, I never had an issue that time with cuff size at the hospital. I always asked, and they either always had the right cuff already, or were willing to go get it without arguing about it. That was a refreshing change!

Pregnancy #4:

This was the only pregnancy that I did not have cuffing issues. I selected a homebirth midwife for this pregnancy (a different one than with #3), but because she is a woman of size herself, she knew about the importance of a larger cuff and already owned one.

I can't tell you what a relief it was to just sit back in prenatals and in labor and know that I didn't have to be so constantly vigilant about blood pressure cuff sizes! She not only had the proper cuff size, but she also knew how to take it properly in all the "little" details (which a lot of medical workers don't do correctly either.....things like having you seated with back support, legs uncrossed, raising the arm to the correct height, not talking to you while taking the BP, etc.).

My baseline BP was a little higher in this pregnancy because of my age (early 40s) but with the correct cuff we were able to document that it stayed normal throughout.

I had my home waterbirth after all and it was wonderful.

Other Women's Stories

I have collected stories on my website of pregnant women of size who were almost forced into immediate cesareans because of high blood pressure readings brought on by miscuffing. Here are two. (If you have additional stories, I urge you to submit them to me for documentation on my website.)

L's Story:

I came within an hour of having an emergency c/s at week 33 with my son. They even went as far to have the surgical resident (who would be assisting my regular OB) and the anesthesiologist speak with me. They were just waiting for my regular OB to get to the hospital and see me before they prepped me.

When he did come in and see me, the first thing he did was take my BP. When he reached for the BP cuff, he said, "Is this the cuff they're using to check your pressure with?" I said yes, then he went out and yelled up one side and down the other to the nursing staff about jeopardizing his patient and baby because they didn't use the large cuff. It made a huge difference! The readings went from [about] 180/104 to [about] 114/63. Surgery cancelled!

Usually I'm much more alert than that and demand the large cuff. I had requested it several times in the hospital and the nurses kept saying it didn't matter...[even after delivery] the jerks still wanted to use the small cuff!!!

A's Story:

Having gone through two pregnancies with elevated BP, it became kind of crucial to me to have it done correctly.

When I was pregnant with [my daughter], I would have it done at my OB/GYN office, and have it either normal or slightly elevated. Then I would get to my perinatologist's office and have it skyrocketed.

The first issue was the cuff---until I insisted I get the right sized cuff (my OB didn't even own one, but I made sure the girl ran next door to borrow one from another doctor for each of my visits---the peri didn't have one and was the only doctor in the building).

The second thing was my OB always had me either sit in a chair and not speak while they did it, or they did it with me lying down. The peri always did it...on the exam table, legs dangling, no back support, while they were chatting with me. Finally, upon the recommendation of the peri, I got a unit for home. From that point on, I refused to let the peri's office do it. I would do it myself while I was out in the car, and bring them my reading.

Twice they suggested my OB take [my daughter] by c-section immediately due to high BP. Thank gosh my OB relied more on his own records than on the recommendation of the peri.

Oh, and I had to fight with the insurance company to get a large-sized cuff for my home unit.

And these are the stories of the women whose misreadings were discovered.

How many "obese" women have been pushed into cesareans they didn't need because they were miscuffed and the error was never discovered? How many have had to get magnesium sulfate (good for pre-eclampsia treatment but it makes you feel like total crap) because they were miscuffed and the error never discovered?

Let's be fair; some women of size do truly experience pre-eclampsia and need these interventions as a result. You certainly cannot say that all fat women's experiences with pre-eclampsia in pregnancy have been spurious.

But because miscuffing is such a common mistake in women of size, chances are very high that some fat women have been diagnosed and treated in error. And because all of these interventions carry significant risks, that's a pretty big mistake to make, whether it's from ignorance or from laziness. It really highlights just how important cuff size is, especially in pregnancy.

Summary

Over the many years that I have been running my website on plus-sized pregnancy and reading stories from other pregnant women of size, this issue of blood pressure cuff sizes keeps coming up again and again.

Despite all the many years of research and training out there for medical professionals on the importance of the correct BP cuff size, miscuffing is consistently still a problem....both outside of pregnancy and in it. However, I have to say miscuffing seems particularly pervasive in obstetrics.

Because hypertensive disorders of pregnancy are a very serious potential complication of pregnancy and because the threshold for intervention is very low when a baby is involved, accurate blood pressure readings are particularly important during pregnancy.

This is even more critical for "obese" women, because many providers assume fat women are automatically going to develop pre-eclampsia anyhow, and because using the wrong blood pressure cuff is such a common error.

You would think that this would mean that attention to the proper cuff size would be particularly strong in obstetrics, but in reality, many women find that there is even less attention to it in obstetric offices and on labor wards.

Therefore, it's critical that pregnant women of size:

• know their own arm size (in centimeters!) and which cuff size they need


• ask about cuff size EVERY TIME blood pressure is taken in pregnancy, labor, or postpartum (and double-check the range printed on the cuff if they are borderline in size)


• train their partners and labor support personnel to ask about cuff size for them during labor if they are too preoccupied


• learn to be assertive about proper cuff size and not allow themselves to be bullied or dissuaded from the proper cuff


• consider purchasing their own cuff and bringing it to every appointment and to the hospital if they are supersized, borderline in arm size, or if they have very heavyset arms

Blood pressure cuff size is an important issue for people of size everywhere, but it is particularly critical for pregnant women of size to be proactive about cuff size.

Sharing Our Blood Pressure Miscuffing Stories

The importance of using the correct-sized blood pressure cuff for people with larger arms has been established in the research for many years. You'd think this would be a moot point by now.

Yet many people of size report being miscuffed or having to argue about cuff size with their healthcare workers, even now. Why does this still happen?

For one thing, not all providers carry larger cuffs. Sometimes, clinics try to cut costs by not ordering larger cuffs, or they may not be aware just how strongly miscuffing can affect blood pressure.

Other times, larger cuffs are available but medical personnel simply do not want to go to the trouble of finding them.

This is actually distressingly common; I have had this happen to me numerous times in the last 15 years, and have heard from many other women of size who have experienced similar issues.

I have many stories about this, but let me just share a brief example of one here, and then I'd like to hear your stories.

A few years ago, I had gone to an urgent-care clinic for antibiotics for an ear and bronchial infection that had rapidly deteriorated; I wanted to get some quick antibiotics for it to keep it from getting worse before I could see my regular doctor.

While there, they of course wanted to take my BP. That's fine. As always I asked to make sure it was a large cuff; it was not. Therefore, I refused to have my BP taken.

I made sure they understood that the problem was not taking my blood pressure (which was usually normal); it was taking it with the wrong-sized cuff.

Didn't matter. They treated me like I had high BP and was just trying to avoid documenting that. (After all, I was fat and that means I probably had hypertension, right?) And oh, did the pressure ever start to just give in.

They told me the large cuff was "out for repair" and they had to use the regular one because they "had" to have something to write down in the records. I refused to have it done that way because I didn't want an artificially-inflated reading on my records.

They tried to tell me that the using the large cuff only made a few points' difference in BP and wasn't that important. I told them that it could make a very large difference indeed and continued to refuse.

They tried to tell me that as long as the cuff fit around my arm, it was fine. I pointed out that this was not true, that it was the size of the bladder inside proportionate to my arm size that was the real issue.

They tried to talk me into taking my BP on the forearm instead. I told them that this method was not that accurate and since it wasn't an emergency and my BP didn't have anything to do with why I was there (the ear/bronchial infection), I would not consent to that either.

Finally, in a stroke of genius, they appealed to my sense of science. They said, "Let's do an experiment and see just how much difference it makes. What's your normal BP; we'll compare that with the results we get from this regular cuff. Let's see whether it makes a lot of difference."

Being the foolishly gullible curious person that I am, I fell for it. (That was stupid. They weren't interested in the science at all, just in getting a reading that they could write down in my records.)

Long story short, my blood pressure was 50 points higher with the regular cuff; it was normal with the large cuff I had it taken with at another doctor's office the next day. But that inaccurately high reading is in my permanent record now, forever.

I have had several other experiences where healthcare workers tried to take my BP with the regular cuff. It's happened even in my regular doctor's office, which usually knows to use the large cuff with me. That's why it's so important to ask every time.

In addition, miscuffing was a problem for me in 3 of my 4 pregnancies. More on that soon....just want to point out that if it happened in THREE OF FOUR pregnancies (and fairly recent ones, too), it's a pretty darn common problem.

Research on the errors that miscuffing causes has been around for more than 25 years, and while miscuffing is less common than it used to be, it is still a distressingly frequent problem.

Healthcare workers get training in the importance of cuff size, but it routinely gets disregarded or forgotten over time. It is definitely something that people of size need to be on the alert for.

Do you have any stories of miscuffing? What happened? How did you handle it? If you complained, how did the authorities respond?

*Coming soon......miscuffing in pregnancy and why correct cuff size is even MORE important when you are pregnant.

The Importance of Blood Pressure Cuff Size

I've written about blood pressure cuff sizes on my pregnancy website before, but recent comments suggest to me that perhaps it's time I revisit the importance of blood pressure cuff sizes.

So today, we start a small series about the importance of the proper blood pressure cuff size. This is an important issue for fat people of any gender or situation, but it's particularly vital knowledge for fat pregnant women, as we'll explore in a later post.

Why Blood Pressure Cuff Size Is Crucial

The size of your blood pressure cuff is of critical importance in getting proper medical care. If you have your BP taken with the incorrect cuff, the result will be inaccurate and you may get inappropriate treatment.

• If you use a cuff that is too small, the resulting blood pressure reading will be too high.
• If you use a cuff that is too large, the resulting blood pressure reading will be too low.

Being off in either direction can have significant health implications.

For example, if they use a too-small cuff (undercuffing) and you are incorrectly diagnosed with high blood pressure as a result, you will be given strong drugs which may have significant negative side effects, yet without any benefits to offset these risks.

On the other hand, if your blood pressure is truly high and goes undiagnosed because they are using a too-large cuff (overcuffing), it can lead to damage to your blood vessels, stroke, and heart attack.

Either way, what is most important is to have ACCURATE data on which to make medical decisions.

Using the wrong cuff size (miscuffing) means that any readings you get are meaningless. Always insist on the correct cuff size before permitting a blood pressure reading.

Miscuffing is Very Common

Research demonstrating the importance of proper cuffing has been around for more than 25 years, yet it remains one of the most common medical mistakes made with people of size.

One classic study on the importance of correct cuffing was Maxwell (Lancet, 1982). This study examined "obese" people already diagnosed with high blood pressure, then re-took their blood pressure with the correct cuff for their arm size. They found that 37%----more than ONE THIRD!----of obese hypertensives were incorrectly diagnosed and actually had normal blood pressure.

Linfors (1984) found twice the level of high blood pressure in "obese" subjects with the standard BP cuff compared to the large adult cuff. Numerous other studies since then have confirmed that using a too-small cuff significantly overestimates blood pressure in "obese" people (sometimes called "Spurious Hypertension").

Of course, cuff size is not just an issue for fat people. A recent study showed that a "standard" cuff often underestimates blood pressure in very lean people; about 80% of the "lean" pregnant women in this study had their blood pressure underestimated with a standard cuff. Thus, many skinny folks may be told that they have normal blood pressure when in fact they have hypertension and are being untreated.

Correct cuff size is an important issue for people of all sizes, but experts agree it is particularly paramount for the "obese."

Typical Cuff Sizes

Do you know what your arm measurement is? You should. Go get a tape measure right now and see what it is. Measure at the mid-point of your arm with a flexible cloth measuring tape.

Once you have measured, memorize that number so you will have it at the tip of your tongue if a cuffing question comes up at an appointment.

If you can, measure it in centimeters because that's how BP cuffs are labeled. However, if you can only measure in inches, click here to help you convert your measurement. (Or do it yourself; multiply by 2.54 to convert inches to cm; divide to go the other way.)

BP cuffs typically come in three sizes--adult, adult large, and "thigh" cuffs.

The adult size is meant for an average-sized adult. The large cuff is meant for people with larger-sized arms (like men with very muscular arms, or "overweight" and "obese" people). The so-called "thigh" cuff is an even larger cuff which is used for supersized people or people who carry a lot of extra weight in their arms.

• Regular Adult Cuff: 27-34 cm, up to 13.4 inches
  
• Adult Large Cuff: 35-44 cm, 13.8 inches to 17.3 inches
  
• "Thigh" Cuff: 45-52 cm, 17.7 inches to 20.5 inches

Research differs on exactly when the larger-sized cuff becomes necessary, but the American Academy of Family Physicians states that if the arm circumference is greater than 34 cm (13+ inches or so), a larger cuff size is definitely needed.

Although most fat people will be served by an "Adult Large" cuff, some will need an even bigger cuff. This is the unfortunately-named "thigh" cuff. It's generally used on folks with arms larger than about 17.5 inches or so. Thigh cuff ranges vary a lot, but generally they top out at about 20.5 inches.

What if your arm is larger than that? Never fear, there are cuffs available for you, but they are a special purchase and not likely to be carried by a doctor's office. See below for more information on buying your own specialty cuff or on using forearm measurements instead.

Typical Cuffing Errors

The most common errors in blood pressure cuffing are:

• Using a regular cuff when a large cuff is needed. This error is extremely common; healthcare workers should know about the importance of this but often ignore it because they don't want to go to the trouble of getting a large cuff or because they don't believe it makes that much difference


• Using a large cuff for all obese people, even when a thigh cuff is really needed. Unfortunately, many healthcare workers do not know when a thigh cuff is needed


• Using a thigh cuff for "super-obese" people, even when the upper limits of the thigh cuff are surpassed. Unfortunately, many healthcare workers are not aware of the upper limits of the larger cuffs

If you arm is even remotely borderline, it's very important that you always look at the cuff size range printed on the side of the cuff. If you are not within the range listed or are very close to its upper limits, request a different size and don't let them talk you out of it.

Common Cuffing Questions

What if my arm is close in size to the cutoffs? Which do I use?

One of the most difficult cuffing questions is what to do if your arm measurement is on the borderline between two cuff sizes. In this situation, it is difficult to know which way to err. You don't want to use the larger cuff and miss some hypertension that truly needed treating; on the other hand, you don't want to be treated for something you don't really have either.

Research shows that the error rate begins to increase as you get close to the cuff size cutoffs. Sprafka found that blood pressure cuff sizes made a significant difference in the prevalence of hypertension, even among people who were marginally large and whose arm circumferences were right around the cuff cutoff of about 13 inches. They stated:

Using a cuff one size smaller than appropriate resulted in...[an overestimation of the prevalence of hypertension of] approximately 36%.

Generally sources suggest that you should err on the side of the larger cuff if you are truly borderline because the degree of error is significantly greater when a too-small cuff is used than when a too-large cuff is used.

Do I really need to check the cuff size every time I have my BP checked?

If you need a larger cuff, you need to check that they are using the correct cuff every time you have your BP taken. Never take it for granted, even if they've always done it correctly before.

However, you don't necessarily have to check the range printed on the side of the cuff every single time unless you are near the upper limits of the cuff size. If you are in the middle of the large cuff range, just about all the large cuffs will probably work for you. Just make sure they are using a large cuff.

But if you are borderline it all, it really behooves you to check the range on the cuff. This is because BP cuff sizes are not standardized. Each maker uses its own cutoffs; the numbers listed above are merely general guidelines. Although it's unusual, it is possible to go to one office and need a large cuff, yet need a thigh cuff with the same arm size at another office.

The bottom end of cutoffs for large cuffs (just over 13") tends to be pretty standardized, but the upper end is not. It can vary by quite a bit. Therefore, if you are closer to the upper cutoff between large and thigh cuffs (or at the upper end of the thigh cuff range), you will need to check the cuff sizes printed on the cuff.

Cuff sizes are usually printed right on the side of the cuff (in centimeters, of course). If you know your arm size in cm, you can easily see if you are within the range printed on the cuff. That's why it's so important to memorize your arm size.

What about forearm readings?

In a pinch or in an emergency situation, a regular cuff can be used on your forearm; this will give a general "ballpark" picture of your BP but has not been found to be accurate to the degree really needed for most non-emergent treatment decisions.

Graves (2001) notes that while forearm blood pressure readings are possible, "These readings are not usually performed as falsely higher diastolic blood pressure readings may be obtained."

A Brazilian study (2004) found that forearm blood pressure readings with a standard cuff tended to overestimate BP readings compared to upper arm measurements with an appropriately-sized cuff. Another recent Missouri study (2008) found a similar result.

Singer (1999) found that forearm readings were within 20 mm Hg of upper arm readings in the majority of people, which is not that significant in an emergency situation with non-pregnant people. However, a difference of 20 points can make a lot of difference in treatment decisions in pregnancy, or if a healthcare provider is trying to decide whether or not to put you on high blood pressure medicine when you are borderline.

Therefore, forearm BP readings should be reserved mainly for emergencies in which a BP is needed now, or for supersized folks whose arm size is over 50 cm but who do not have quick access to a specialized cuff.

Generally speaking, forearm readings should not be relied on for regular routine readings or for making non-emergent treatment decisions, nor should they be relied on for decision-making or interventions in pregnancy unless there is a critical emergency.

Buying Consistency: If In Doubt, Get Your Own

Even if you are in the mid-range of the large cuff (which should be routinely available in every medical office or facility), you cannot always count on the doctor's office or even the hospital to have the correct size blood pressure cuff, for it to be in working order, or for medical personnel to be willing to use it. Therefore, you might want to consider purchasing your own blood pressure cuff and taking it with you to each appointment and to the hospital.

"Supersized" people or those with heavy arms may particularly want to invest in their own blood pressure cuffs. While many offices carry large cuffs, not all carry a thigh cuff. If your arm is over 17-18 inches in circumference or you weigh significantly over 300 lbs., you might especially want to consider buying an appropriately-sized cuff of your own.

Undercuffing is chronic in these groups, as few healthcare workers realize when a thigh cuff is required. Sadly, even when they know a thigh cuff is needed, many don't bother to use it, even in very large people.

If your blood pressure is borderline, if your arm is very heavy, or if you are supersized, investing in your own cuff is probably a good idea.

Nowadays, a number of internet companies offer blood pressure cuffs for sale; be sure you only buy one with the correct size cuff for you. Don't just accept that the cuff size is "large;" you need to get the exact range because of the lack of standardized cuff sizing.

In addition, if possible, choose a cuff whose accuracy has been tested and validated. Many monitors out there on the market have not had their accuracy verified. Remember, you want accurate data on which to make your treatment decisions.

The internet company, Amplestuff, sells blood pressure cuffs in varying sizes (including sizes for arms over 20 inches). It is one of the only good sources for the very largest of cuffs. These cuffs attach easily to the blood pressure devices in most offices, and then accuracy is always at your fingertips.

Summary

Blood pressure cuff size is a critical issue in healthcare for people of size, yet despite years of research on the issue, miscuffing is quite common. Some sources suggest that up to 1 in 3 BP readings are miscuffed, and that the "obese" are particularly at risk for miscuffing issues.

If your arm is over about 13 inches, you need to ask about cuff size EVERY time you get your blood pressure taken. Even if the office routinely uses the larger cuff with you, you still need to verify cuff size; don't ever take it for granted that they are using the correct cuff size.

Blood pressure is a very important health issue. If you truly have hypertension, it really does need to be treated. However, these decisions need to be made on the basis of accurate data, and research is very clear that miscuffing is still a significant issue for fat folk.

Coming soon: Your chance to share your BP miscuffing stories, the heightened importance of BP cuff issues during pregnancy, and how to deal proactively with resistance from healthcare workers.

Ultrasound Measurement of Cesarean Scar Thickness

A recent press release trumpeted the "new" findings of a Canadian researcher that cesarean scar thickness may predict the risk of uterine rupture in future pregnancies. Press releases stated it might be used to predict who should be encouraged to try for a Vaginal Birth After Cesarean (VBAC, pronounced "vee-back") or who should just schedule a repeat cesarean.

I was asked about this here on my blog, too, so I have prepared a detailed post about the pros and cons of this topic.

A word of warning--this post will be fairly technical and long. If you find that sort of thing boring, please feel free to skip this post. I promise, not all my blogging is like that. But sometimes it's important to get into details, and this is one of those times.

The Cliff Notes Version

In a nutshell, beware scientists with a self-promotion agenda.

Remember, this is the era of "Science By Press Release;" this particular press release coincided with a presentation on the topic at the Society for Maternal-Fetal Medicine's annual meeting in San Diego in January. The study hasn't been peer-reviewed or even published yet. It's a little premature to be drawing conclusions or altering policy from it.

Although the findings are interesting, caution should remain the byword in the use of ultrasound to predict the risk of uterine rupture. There are a number of very legitimate concerns about its accuracy, its utility, and the misuse of results that might occur with its widespread adoption.

Remember the take-away message:

Be cautious about using scar thickness to estimate uterine rupture risk. At this point, it deserves further study, but it should not be used to determine who should (and shouldn't) get a chance at Vaginal Birth After Cesarean.

A Little Background Information

First, a few explanations are in order. Birth professionals who read this blog will understand the terms being tossed around, but others may not. So let's take a moment to do a little explaining.

First, remember that one of the risks after a cesarean is that the scar from the incision may come apart in the next pregnancy (the risk is somewhat higher with labor but exists even without labor). This risk is very small, but potentially very serious. However, there are different degrees of separation that must be differentiated.

Terms for scar separation tend to be very inconsistently used, even by medical professionals, but generally fall into a few categories.

Markedly Thin Lower Uterine Segment

Sometimes the prior cesarean scar gets very thin but doesn't separate. This is usually called a "markedly thin" or "paper thin" lower uterine segment. Occasionally some sources will call it a "window" because they can 'see' the baby's hair or features, like a face pressed up against a nearly opaque window. However, "window" is a very inconsistently used term so other terminology is generally preferable.

It is unclear whether or not a "markedly thin" lower uterine segment (LUS) is risky. Many doctors assume it is a disaster about to happen, but there have been a number of women who have experienced this and still gone on to have a VBAC (with no rupture) later on---so obviously those LUS were stronger than the doctors thought.

On the other hand, in some cases, it might have been something about to happen---the problem is we just don't know for sure. Some thinning of the LUS is normal at the end of pregnancy and during labor; it is unclear whether at some point thinning becomes abnormal, and if so, at what point that happens. It is a matter of some disagreement.

Dehiscence

Sometimes the scar actually comes open, like a zipper coming a bit unzipped, but the separation is mild and has very little bleeding. This is a "dehiscence" (although some sources call this a "window;" the inconsistency of that term is why it is best avoided).

One medical definition of dehiscence is:

Any defect in the preexisting cesarean scar with no maternal or fetal compromise

Although potentially serious, a dehiscence generally has a good outcome and is clinically fairly insignicant.

Uterine Rupture

Other times, the scar separation is more significant (a "uterine rupture" or UR) and the woman can have significant bleeding and difficulty recovering. A common medical definition of uterine rupture is:

A defect that involved the entire wall of the uterus, was symptomatic, and required operative intervention

A uterine rupture is always dangerous and needs attention, but many babies and mothers are fine with prompt treatment.

On the other hand, sometimes uterine rupture is truly catastrophic, especially if the placenta pulls away from the uterus during the rupture, depriving the baby of oxygen. The baby can sustain brain damage or even die, and the mother can lose her uterus or die too.

The risk of truly catastrophic uterine rupture is small, but if it happens to you, it's devastating. It is certainly something to be taken very seriously indeed.

Weighing the Risks

Although VBAC has a small but potentially very serious risk of uterine rupture, there are also risks from choosing repeat cesareans, including severe hemorrhage, anesthesia accidents, infection, hysterectomy, serious breathing problems for the baby, and maternal death. Furthermore, in future pregnancies, the risk of the placenta implanting abnormally rises significantly, and this can lead to prematurity, fetal death, maternal hysterectomy, and maternal death.

In many years of birth-related work in person and on the internet, I have known women and babies harmed both by uterine rupture during labor and by repeat cesarean and its complications. Let me assure you, I take both very seriously. I urge readers to have the utmost respect and compassion for all those who have their lives impacted by either.

You can debate the relative safety of VBAC vs. repeat cesareans for a long time, but the bottom line is that there is NO 100% "safe" choice after a cesarean. There is risk with trying for a VBAC, and there is risk from deciding on a repeat cesarean.

Although the risk of a severe complication with either choice is low, if it happens to you, it is overwhelming and devastating.

That's why it's so important to use cesareans only when truly needed.

The Allure of the Crystal Ball

In an ideal world, doctors would be able to figure out ahead of time who is most at risk for uterine rupture so those women could opt for a repeat cesarean, while the others could opt to try to VBAC if they wanted (called a "Trial of Labor" or TOL).

Much of the VBAC research in the last few years has been aimed at trying to determine the most important risk factors for uterine rupture. The problem is that a lot of research on UR is contradictory; there is no "smoking gun" study that shows a clear way to predict or avoid uterine rupture.

Even when a risk factor for UR is found, it's only a risk factor and not a true predictor; the vast majority of women with that risk factor will not experience a rupture even if they labor. If you insist on mandatory ERCS for all women with risk factor "X," the majority of those repeat cesareans will not have been necessary and will expose all those women to the considerable risks of repeat cesareans while preventing only a very few ruptures.

Coming up with a reasonable way to manage risk in women with a prior cesarean is one of the great dilemmas of obstetrics today. Frankly, the best solution is to prevent the first cesarean whenever possible, but with cesarean rates at around 1 in 3 of all childbearing women, this is not happening.

Failing primary prevention, the best course is to offer fully informed consent about risks and benefits of each choice, and then let the woman choose which option to pursue. In the end, the decision should be the woman's.

Measuring Cesarean Scar Thickness - The Bujold Study

Measuring cesarean scar thickness is one way doctors try to predict the risk of uterine rupture and know who would be the "best" candidates for a trial of labor and who might be at more risk.

Bujold's study, done in Quebec, measured scar thickness in 236 women. They found that a cut-off of 2.3 mm helped determine a group more at risk for UR in their study group.

Since the study has not even been published yet, it is difficult to evaluate. Here are some of the details given in the press release:

Bujold's study involved 236 pregnant women who had delivered previously by C-section but who planned a vaginal delivery. They used ultrasound to measure the lower part of the uterus, which correlates with scar thickness from the previous C- section, and then followed the women through their deliveries.

During labor and delivery, three of the women had a complete uterine rupture. In six, the scar reopened. Women who had uterine rupture had a very thin scar, Bujold said.

"We found the cutoff is probably 2.3 millimeters" in terms of scar thickness, he said. The average risk of rupture is about 1 percent, Bujold said, but in the study, "if you had a scar smaller than 2 mm, your risk of rupture [was] about 10 percent."

Please note, it's important to look at the strengths and weaknesses of this particular study....and there are several to look at.

The first problem here is that this study is small; the study group had only 236 women. You need a much larger study group than that to determine the significance of any particular risk factor on such a rare complication.

Second, the study has a somewhat higher-than-usual underlying rupture rate. Whenever a study reports a higher-than-usual complication rate, it's always important to dig deeper. A high UR rate suggests that some other factors may be at work.

A large body of research shows that induction and augmentation (using artificial drugs to start or strengthen labor) significantly increase the risk of rupture. This is particularly true if multiple types of induction drugs are used, or if the mother has never had a prior vaginal birth.

Uterine rupture risk is often quoted as being around 1% in a TOL, but that averages together both induced/augmented labors and spontaneous labors. (In VBAC labors that are spontaneous, rupture rates usually hover around 0.5%, or half of a percent.) In this study, the rate of actual ruptures was 3/236, or about 1.3%. Therefore, in all likelihood, factors like induction and augmentation are strongly at work here too. We don't yet know if they controlled for those factors.

It would be interesting to know the details of the cases of the 3 ruptures and the 6 dehiscences, to find out how many involved induced or augmented labor. In many studies, the majority of ruptures and dehiscences involve artificial strengthening of labor contractions.

The other big variable here was partly addressed by Bujold's presentation; the type of suture repair done. This is another giant controversy in VBAC these days; one-layer vs. two-layer repair of the uterus.

Bujold has done research in the past showing that a one-layer repair of the uterus strongly increased the risk of rupture in later pregnancies. However, other studies have not found similar results. It all depends on the study you look at.

A further variable not accounted for in most one-layer vs. two-layer debates is the TYPE of suture material. Bujold and his team used a different type of suture material than the one-layer studies done in the U.S.; his group's higher rate of rupture may simply have to do with the TYPE of suture material rather than the number of layers used. Alas, there has yet to be a definitive study on this topic that controls adequately for other factors.

In this study (as reported here), Bujold found that the combination of a single-layer repair and a scar thickness less than 2.3 mm strongly increased the chances of uterine rupture (21.8 times the risk). That's a very strong increase of risk, which definitely deserves further study.

But again, other studies on single-layer sutures have not found the same level of risk with single-layer suturing. Would other studies measuring scar thickness in single-layer sutured mothers find a similar increase? We just don't know. In addition, we don't know if the type of suture material, pattern of stitch, and induction/augmentation status were controlled for.

This is far from a definitive study on this topic and should be taken with a large grain of salt. Its results merely call for further study, not changes in hospital policy.

The Problems with Studies Measuring Cesarean Scar Thickness

There are a number of problems with studies that have been done using cesarean scar thickness as a predictor of uterine rupture.

The first major problem with this is the issue of inter-observer variation. The type of measuring done here is fairly subjective, particularly between different observers and different methods. Transvaginal ultrasound seems to be more accurate than abdominal ultrasound, yet often abdominal ultrasound is what's being used. Should a woman's chance at even trying for a VBAC rest on data that can vary significantly depending on who (and what) is doing the measuring?

As noted above, another significant problem with these studies are their small sizes. From a discussion of the topic on the VBAC Facts blog:

Where we do draw the line at what is “thick enough?” This is where studies come into play. There are several studies that focus on measuring uterine thickness via ultrasound on women with prior cesareans...but none of them are large enough to make any definitive decisions.

When looking at something like uterine rupture that happens about half of a percent of the time, you need to include thousands of test subjects in order to get an accurate assessment of the frequency of the occurrence. We just don’t have that here.

These are interesting preliminary studies that should be duplicated using thousands of women. If there is a way to accurately predict which scars will rupture, this is important information to have, but there is currently insufficient evidence available.

The largest study on uterine scar thickness is the main original one (Rozenberg et al, Lancet, 1996). It was the largest by far with 642 women, but even that falls considerably short of the thousands needed to have the power to determine the statistical significance of a particular risk factor on a rare occurrence.

Third and most importantly, each study finds a different cut-off spot where the risk for rupture increases and becomes "too much."

The original Rozenberg study from 1996 found that a cut-off of 3.5 mm was most useful in determining when risk went up; the recent Bujold study found that a cut-off of 2.3 was the most useful. That's a pretty fair descrepancy. How do you reconcile the difference?

In one study the cut-off is 3.5 mm, in another it's 2.5, 2.3, 2.0, 1.6, 1.5 or 1.0 mm. There are studies to support each of those cut-offs. Which cut-off do you choose to use?

Here's a list of several scar thickness studies in women with prior cesareans. Which one do you trust in?

Study and Cut-off Where Risk Went Up

Rozenberg, 1996 - 3.5 mm (n=642 women)
Qureshi, 1997 - 2.0 mm (n= 43 women)
Montanari, 1999 - 3.5 mm (n= 61 women)
Asakura, 2000 - 1.6 mm (n=186 women)
Suzuki, 2000 - 2.0 mm (n= 39 women)
Gotoh, 2000 - 2.0 mm (n=348 women)
Sen, 2004 - 2.5 mm (n= 71 women)
Cheung, 2005 - 1.5 mm (n=102 women)
Bujold, 2009 - 2.3 mm (n=236 women)

Other Experts Express Concern

The reason that most doctors are not doing this ultrasound scar measurement routinely already (despite the concept having been around for more than 10 years) is because they recognize the weaknesses of it.

In one 2003 survey, only 16% of Canadian doctors were using ultrasound to predict rupture risks. Doctors know the varying cut-off results means that it's not a very reliable method of determining risk.

These concerns were reflected by other doctors who commented on Bujold's press release.

Dr. Shoshana Haberman, director of perinatal testing services at Maimonides Medical Center in Brooklyn, N.Y., said she has been doing this measurement on women with previous C-sections for a few years. And while the new study results are interesting, she said, the prediction method is not yet definitive.

"We need more data -- that's the bottom line," Haberman said. "We need more data to decide the cutoff."

The ultrasound measure is also operator-specific, she added, so it could vary from person to person.

A Strong Potential for Misuse

In the press release, Bujold states that the study should be used to encourage more women to VBAC, given the known increase in risk with each repeat cesarean.

"There is a growing concern about the increase in cesarean births because there is a body of evidence showing that they are associated with higher rates of maternal and infant complications," said Emmanuel Bujold, M.D., with the Department of Obstetrics & Gynecology, Faculty of Medicine, Universite Laval, Quebec. "There are far fewer complications to the mother and infants as a result of a vaginal birth," he continued, "So it is important to determine when a patient with a history of prior cesarean section can have a vaginal birth safely."

However, although this statement sounds well-intentioned, it is disingenuous. Most of the time, these sorts of cut-offs are being used to DENY women access to VBACs, not encourage them. VBACs are extremely hard to come by these days in many areas; this will only be used as ammunition against them, not encouragement for them.

At best you could make a case for using scar thickness measurements as a way to strongly increase the trial of labor rate for women over some random cut-off, but it simply can't be used as a way to "guarantee" no rupture in a VBAC attempt. Nor does it guarantee a definite rupture in women who labor below the cut-off. There are cases of women rupturing above even the 3.5 mm cut-off, and many cases of women who have not ruptured below the arbitrary cut-offs set in these studies.

Alas, it's just not that simple, and no one has rupture-specific psychic powers. It would be wonderful if this were THE key to avoiding uterine rupture and encouraging more VBACs, but it is not.

Summary

There are too many problems yet for doctors to start doing universal ultrasound measurements of cesarean scar thickness and using them to determine who is "allowed" to have a trial of labor and who is "required" to have a repeat cesarean.

You might make a case for using this data to counsel women more closely about their possible risks, as long as you mentioned the strengths and weaknesses of the studies about it, and as long as the ultimate choice was up to the parents. Or it might be used for deciding who needs the most careful monitoring during labor after cesarean.

However, in reality, it's going to be used to DENY women the right to decide for themselves, either by requiring mandatory repeat cesareans in women whose scar thickness falls below an arbitrary cut-off, or by using the data to scare women out of considering a VBAC (without sufficient mention of the weakness of the data).

If a woman falls into a group that might be at increased risk for uterine rupture, the logical thing to do is to counsel those parents about their possibly increased risk from a TOL, as well as the possible current and future risks from repeat cesareans.

At this point, it should NOT be used for denying a woman the right to try to VBAC. Yet you know that's how it's going to be used. In fact, research shows that it HAS been used this way already, despite the many weaknesses of existing research.

Informed consent, yes.......coerced surgery, no.

Before this becomes standard of care, there needs to be a LOT of very large, multi-center, randomized, double-blind studies, using ultrasound measurements from multiple observers, and controlled for other factors like suture type/material, induction/augmention, etc.

Frankly, right now, measuring scar thickness is just another way to prevent or scare women from having a VBAC. The intent behind the investigation may be reasonable, but the pratical usage will not be.

Until there's a lot more study on this topic, it is not an accurate way to assess the risk for potential uterine rupture, and it should not be used to determine who should not be "permitted" to try for a VBAC.

Right now, it's just another data dredge and publicity ploy, rather than a really tested and true way of assessing future risk.

As Gretchen Humphries, advocacy director of the International Cesarean Awareness Network says, "It isn't anywhere close to clinically useful and we all know it'll get misused."

Just remember the take-away message:

Be cautious about using scar thickness to estimate uterine rupture risk. At this point, it deserves further study, but it should not be used to determine who should (and shouldn't) get a chance at Vaginal Birth After Cesarean.

A Little Historical Perspective on Weight Gain in Pregnancy

Preventing Pre-Eclampsia and Big Babies

Years ago, doctors regularly advised women to strictly limit their weight gain in pregnancy. They viewed this as a way to prevent pre-eclampsia (high blood pressure issues in pregnancy) because one of the symptoms of pre-eclampsia is a high weight gain from retaining fluids.

They decided that the large weight gain must be causing the pre-eclampsia, and therefore, preventing a large weight gain would help prevent pre-eclampsia.

They also wanted to prevent women from having large babies, so they strongly counseled women of all sizes to limit weight gain in order to get a smaller baby.

[Not only did they restrict weight gain, they also advised women to smoke to keep down their weight gain and fetal size, or to use diuretics to prevent fluid retention, both of which were later discovered to cause serious problems in pregnancy. Doh!]

All this was in the name of a worthy goal----preventing pre-eclampsia, which can be a very serious complication of pregnancy, and which is potentially deadly to both mother and baby. Their hearts were in the right place, but their methods were ill-considered and extreme.

Furthermore, the safety of this approach had not been established before it was adopted, as is unfortunately common in obstetrics. (Think of all the babies damaged when their mothers' doctors prescribed DES.)

Unforseen Consequences: Underweight Babies

What they found out later was that these extreme approaches actually CAUSED more harm then they averted. Many babies were born too small or very stressed; some no doubt died as a result of these interventions.

We also know that babies born underweight or "small-for-gestational age" (SGA) have more health problems later in life so the consequences of restricted fetal growth go far beyond problems at birth.

This is why the Institue of Medicine (IOM) adopted new weight gain guidelines in 1990, raising the recommended weight gains in pregnancy. They noted years of research that showed that low weight-gain in pregnancy caused an increase in SGA babies....in women of all sizes.

They also noted that in the 70s, when weight gain restrictions began easing up, there was a strong reduction in the occurrence of SGA babies.

So they raised the guidelines, and then began the big job of trying to get doctors to believe in this new system of weight gain guidelines. It was a difficult job.

Current IOM Weight Gain Guidelines

The old weight gain recommendations vary by source and by decade to some extent, but generally they fell somewhere between 10-20 lbs. By the 1970s, several organizations set a desirable range of around 20-25 lbs. or so.

The IOM raised these guidelines...but not across the board. They differentiated weight gain recommendations by BMI. Their guidelines were:

• "Underweight" women: 28 - 40 lb. weight gain
• "Normal" Weight women: 25 - 35 lb. weight gain
• "Overweight" women: 15 - 25 lb. weight gain
• "Obese" women: at least 15 lb. weight gain

The reason they had different weight goals by BMI was because weight gain's effect on fetal size varies by pre-pregnancy BMI.

The highest risk for SGA babies was in underweight women who didn't gain enough weight in pregnancy. Research clearly shows that gaining more weight can prevent many SGA babies in this group, so they raised the upper limit in this group to 40 lbs.

The effect of greater weight gain in preventing SGA babies is less pronounced as maternal size goes up; thus they felt that smaller gains were justifiable in the other groups. Still, women of "normal" size were now allowed to gain up to 35 lbs., which was a little more lenient than in the past.

The effect of weight gain on SGA babies is least strong in overweight and obese women, so therefore they felt only a small weight gain was appropriate in this group.

However, they did note that very small weight gains/losses caused increases in SGA babies across the board, even in obese women, and therefore they were not comfortable in recommending <15>This has been very controversial; many doctors still believed that obese women should gain little or nothing in pregnancy. They believed a larger gain in fat women would lead to a stronger risk of....ta da!!....pre-eclampsia. And big babies. And cesareans. And would result in more obesity after the pregnancy because of retained weight. So they've been chafing under these "guidelines" ever since.

Pressure to Revise the Weight Gain Guidelines

This chafing over guidelines has reached fever pitch now as a result of the obesity hysteridemic. More and more are pressing for lower weight gain goals.

Recently, a number of doctors have banded together to pressure the IOM to revise its guidelines on weight gain in pregnancy, and in particular to lower the guidelines for obese women.

They are hawking the same old concept again, namely: Large women have a higher risk for pre-eclampsia and big babies, so if we prevent a large weight gain in them, we'll lower the risk for pre-eclampsia and get smaller babies!! And prevent further obesity afterwards!!

Know what guidelines they are proposing for obese women?

• Class I obese women (BMI 30-34.9): 10 - 25 lbs. gain
• Class II obese women (BMI 35-39.9): 0 - 9 lbs. gain
• Class III obese women (BMI >40): 0 - 9 lbs. loss

That's right, they are proposing that some fat women BE REQUIRED TO LOSE WEIGHT DURING PREGNANCY.

Alas, their P.R. campaign is working; the IOM has begun meetings to discuss revising weight gain guidelines again.


Coming Soon: Deconstructing the research being used to justify lowering these cutoffs.

Metformin and B Vitamins?

Many people of size take metformin (a.k.a. Glucophage). They might take it for insulin resistance/PCOS issues, or they might take it for blood sugar issues....or both, since the two are often related.

This post is of particular concern to those women of childbearing age who take metformin, but anyone on metformin should know about it.

I recently ran across some research linking metformin with low levels of B vitamins, particularly vitamin B12 and Folic Acid.

Although the worst effects seem to happen with years of treatment and higher dosages, even short-term treatment (16 weeks) reduced the levels of folate and B12.

These lowered levels of folate and B12 also seem to be linked to an increase in homocysteine levels, which is commonly seen after metformin is started. Now, what significance this has, if any, is still being debated. In terms of general health, homocysteine levels may be tied to heart health; high levels are considered a risk factor for cardiovascular disease. There is some research indicating that administration of B-group vitamins reduces homocysteine levels in non-pregnant PCOS patients treated with metformin. But we don't really know yet if lowering homocysteine levels results in any meaningful reduction in long-term endpoints like decreased heart attacks or mortality.

However, we do know that some people on metformin do develop megoblastic anemia at some point during treatment. So certainly, it's seems like it's something that anyone on metformin should be aware of and monitored for periodically.

It might even be sensible to take extra B vitamins (B group complex, presumably) while on metformin, although formal studies on the value of that seem to be lacking so far. There is also one study that found that supplemental calcium may help blunt or reverse B12 malabsorption with metformin.

Implications for Pregnancy?

All this information about metformin impacting B12 and folic acid levels makes me wonder if there are special implications for women of childbearing age. We know that folic acid levels are important for preventing birth defects like neural tube defects (NTDs, like spina bifida or anencephaly). If a woman with PCOS has been on metformin for years and her folic acid levels are chronically low when she conceives, does this increase her risk for NTDs?

As far as I can tell, no one knows. There doesn't seem to be any increase in birth defects in women on metformin so far, but research is limited. Because preliminary research on metformin in pregnancy indicates that it cuts the risk for miscarriage and gestational diabetes in women with PCOS, it's likely to be used more and more often in the future, provided the research continues to be supportive.

So the question becomes, should women on metformin who are considering conceiving (or who are of childbearing age at all) be supplemented with extra folic acid and B12 (or B vitamins in general)? And if so, by how much? What about calcium, if it helps reverse the malabsorption of B12? Should levels of B12 be monitored during pregnancy?

At this point, I don't think anyone knows for sure. Anecdotally, many women on metformin do seem to be taking additional folic acid at least. Consult your care provider about this topic and what dosages might be appropriate beyond a normal prenatal vitamin. (And if you do decide to take supplemental vitamins in addition to metformin, you should probably take them at different times of day.)