Sunday, January 29, 2012

More Evidence That Vertical Incisions Have Increased Complications

We have blogged about this before, but here's yet another study that vertical (up-down) cesarean incisions in "obese" women have more complications than low transverse (side-to-side) incisions.

As we've  noted before, sometimes there can be legitimate justification for using a vertical incision. However, most of the time, its use in fat women springs from outdated and non evidence-based teachings that an incision under the belly (pannus) predisposes the wound to infection, and that a vertical incision will supposedly lower the risk for infection and improve outcomes. 

Yet when researchers finally got around to actually studying the question, they found that vertical incisions either did not improve outcome OR significantly worsened it, as in this study, where incision type was associated both with infectious complications and with wound separation.

Notice that in this study, ~46%% of "morbidly obese" women with vertical incisions experienced a wound complication of some sort.  Nearly half!   

In comparison, only ~12% of morbidly obese women with low transverse incisions experienced a wound complication.

Yet still, despite more complications with vertical incisions, about 7% of obese women in this study (11% in others) are being subjected to vertical incisions instead of low transverse incisions during cesareans.  That's around 1 out of every 10 to 14 obese women having a cesarean. That's far too high a rate, considering the poorer medical and cosmetic outcomes with vertical incisions.

More and more data is accumulating to show that the most optimal incision is usually the low transverse incision, even in very fat women.  When will doctors heed their own research?




J Matern Fetal Neonatal Med. 2012 Jan 10. Risk factors for wound complications in morbidly obese women undergoing primary cesarean delivery. Thornburg LL, et al.   PMID: 22233403

Source: Department of Obstetrics & Gynecology, Maternal Fetal Medicine, University of Rochester Medical Center, Rochester, NY, USA.
Objective: To determine factors influencing separation and infectious-type wound complications (WC) in morbidly obese women undergoing primary cesarean delivery (CD).  
Methods: Retrospective cohort study evaluating infectious and separation WC in morbidly obese (Body mass index (BMI) greater than 35) women undergoing primary CD between 1/1994 and 12/2008. Chi-square, Fisher's exact, and Student's t-test used to assess associated factors; backwards logistic regression to determine unadjusted and adjusted odds ratios.  
Results: Of 623 women, low transverse skin incisions were performed in 588 (94.4%), vertical in 35 (7%). Overall WC rate was 13.5%, which varied by incision type (vertical 45.7% vs. 11.6% transverse; p less than 0.01), but not BMI class. Incision type and unscheduled CD were associated with infection risk, while incision type, BMI, race, and drain use were associated with wound separation.  
Conclusion: In morbidly obese women both infectious and separation-type WC are more common in vertical than low transverse incisions; therefore transverse should be preferred.

Monday, January 23, 2012

News Flash: Labor Managed Differently in High-BMI Women!

For a long time, doctors have observed a higher cesarean rate in high-BMI women, but always blamed this solely on obesity.

But how would obesity impede labor and result in more cesareans, you ask?

The usual reasons given (based on assumptions or poor research) were soft tissue dystocia (i.e., the fat vagina theory), or inefficient uterine contractility due to high leptin or cholesterol levels (seriously, that's a current theory still floating around, despite evidence that contradicts it).

Yet no one was asking whether the way labor was managed in "obese" women contributed to this high cesarean rate.

Now, for the first time, FINALLY someone is starting to ask these questions!  A Canadian study out earlier this year examined labor management of obese women compared with other women.

And guess what?!  As I've been saying for years, they found that the labors of women of size are indeed managed differently, with more interventions and a much lower threshold for surgery. 

Furthermore, when the study controlled for the use of interventions, the relationship between obesity and cesareans was "markedly attenuated." 

Details from the Study

There are a couple of interesting items in the study worth a closer look.

Induction Rates

First, induction rates went up strongly as BMI increased.  Here's a summary of induction rates by BMI category (delivery BMI):
  • "Normal" BMI (20-24.9)               23.7% induced
  • "Overweight" BMI (25-29.9)         29.3% induced
  • "Obese" BMI (30-39.9)                37.2% induced
  • "Morbidly Obese" BMI (40+)       50.0% induced
Now, some of that increased rate is to be expected, given that fatter women have higher rates of pre-eclampsia and other complications, and induction is more common in women with these complications.  But even so, a 50% induction rate?  Do 50% of all "morbidly obese" women really need to be induced? Come on!

A great deal of research has shown that induction of labor is linked to higher cesarean rates.  This is particularly true for first-time mothers or women who have never had a vaginal birth before, or whose cervix was not ripe before the induction.

So why don't any researchers (including this one) connect the dots between such an extremely high induction rate in women of size and a resulting high cesarean rate?

The authors don't really comment on the induction rates or question them at all; most research never does.  Most authors assume that all these inductions are truly indicated, especially in women of size.  But frankly, they need to question such a high rate of induction more closely.

How many of these inductions were for real medical indications, and how many were for dubious indications like suspected macrosomia or provider fear? 

We know from research that inducing early for a suspected big baby does not improve outcomes, and actually strongly increases the cesarean rate in many studies.  Yet it is common practice still among clinicians to induce labor early if a big baby is suspected, especially in women of size. 

So when you see the 50% induction rate in "morbidly obese" women, how many were for "soft" indications like suspected macrosomia?  And what was the cesarean rate among those induced for "soft" indications? I would love for researchers to look more carefully at induction indications and how that influences cesarean rates in women of size.

We know from another recently published study that high induction rates definitely do have a strong influence on cesarean rates in obese women.  According to the authors of that study:
We conclude that morbid obesity is associated with a significantly higher risk of pre-existing medical conditions, developing antenatal complications, induction of labour, caesarean section and greater birth weight. However, there was no significant difference in caesarean section rates when adjusted for induction of labour. 
More research is needed to further clarify the impact of high induction rates on cesarean rates in obese women, and researchers need to finally start questioning the validity of many of these inductions.

Cervical Status Upon Admission

Another interesting finding that deserves further investigation is a major difference in cervical status upon admission and what might be influencing this.

Women whose cervix is more dilated upon admission tend to have shorter labors and a lower cesarean rate; those whose cervix is less dilated at admission usually have longer labors and more cesareans because their bodies aren't ready to labor yet. 

In this study, 37.9% of women of average BMI had minimal cervical dilation (2 cm or less) upon admission to the hospital.  In comparison, 55.7% of "morbidly obese" women had minimal cervical dilation upon admission.

Yes, this is surely partly due to a higher rate of inductions and therefore less spontaneous labors in the high-BMI group, but it also suggests that perhaps this group is far less ready for labor when being induced.  Again, many authors have noted this and have blamed it on "inefficient uterine contractility" or hormonal deficits, but what if there are other factors they are not considering?

Studies have shown that high-BMI women have longer menstrual cycles and longer gestations; perhaps what is happening is that their due dates are not being sufficiently adjusted for their longer cycle length and as a result, their bodies are less ready for labor when the doctors think they "should" be going into labor. And, as a result, they have more inductions, less cervical ripeness when induced, and more cesareans when the induction doesn't work.

More Interventions

The study found that there was more use of oxytocin augmentation and epidurals as BMI increased.  The pit augmentation increase may reflect the lower level of cervical ripeness before labor, but it may also reflect the common perception among some clinicians that obese women won't labor sufficiently on their own. So they automatically just start pitocin augmentation, without ever looking at whether it's needed or not.

The increased epidural rate may simply reflect the higher rate of inductions and pitocin augmentations; it's hard to go through such induced and augmented labors with little mobility and not need some pain relief.  However, it may also reflect the common practice of strongly encouraging early epidural placement in obese women to avoid a difficult placement later if a cesarean is needed.

(And of course, once that epidural is placed, oxytocin augmentation is often needed to compensate for the way that epidurals tend to slow labor.  It can be an vicious circle.)

Lower Surgical Threshold

The study also shows that doctors were quicker to terminate labor early and move to a cesarean in "obese" women.  In the study, the labors of "morbidly obese" women were terminated about an hour earlier than women of average BMI.

Some of this is understandable; surgery in a very heavy woman is more difficult and takes quite a bit longer than in a woman of average size.  Doctors want to avoid an emergency situation where every second counts to save a baby, and especially so in a woman whose extensive adipose layers may require more time to get to the baby in the first place.  Therefore, doctors may be more prone to intervene early in women of size, before things get to an emergency situation.

Yet most cesareans are not done under truly emergent conditions, and research shows that many women whose progress is slow are able to give birth vaginally if just given a little more time, and their babies generally do just as well.

So doctors have to walk a fine line between not waiting too late and not intervening too early.  From this study, it looks like too many doctors are erring on the side of intervening far too early.  And because cesareans are extra risky for women of size, this is a cause for concern ─ and a potentially modifiable variable for reducing the tremendously high cesarean rate in women of size.

Final Thoughts

As I've been saying for years, the high cesarean rate in obese women is not only about obesity itself, but also about the way that obese women are managed during pregnancy.

Sky-high induction rates, increased utilization of interventions during labor, and a very low threshold for surgical intervention all combine to ratchet up the cesarean rate in women of size.

The important thing to note is that these are all potentially modifiable factors for reducing the cesarean rate in this group.  

Up till now, the only options most doctors saw for lowering the cesarean rate in women of size involved  encouraging weight loss before pregnancy or restricting weight gain during pregnancy.  Yet this research suggests that if doctors simply change their management practices and fear levels around women of size, it's likely that the cesarean rate can be lowered in this group without draconian weight restrictions.

In the Canadian study, the authors concluded: 
Because of the potential morbidities associated with Caesarean section, we must modify our management approaches to allow equal opportunity for a vaginal birth for all women.
Those are strong words for an obstetrical community that's usually pretty mealy-mouthed about these things, and frankly, it's nice to finally hear them from someone other than me.  Bravo to these authors for being willing to advocate for vaginal birth for women of size at a time when some doctors are advocating pre-emptive cesareans across the board for this group.

But if doctors really want to get serious about allowing equal opportunity for a vaginal birth for fat women, first and foremost they need to crack down on the insanely high induction rates, as well as re-examining the use of interventions and threshold for surgery in this group.


References

J Obstet Gynaecol Can. 2011 May;33(5):443-8. Higher caesarean section rates in women with higher body mass index: are we managing labour differently? Abenhaim HA, Benjamin A.  PMID: 21639963
Background: Higher body mass index has been associated with an increased risk of Caesarean section. The effect of differences in labour management on this association has not yet been evaluated.

Methods: We conducted a cohort study using data from the McGill Obstetrics and Neonatal Database for deliveries taking place during a 10-year period. Women's BMI at delivery was categorized as normal (20 to 24.9), overweight (25 to 29.9), obese (30 to 39.9), or morbidly obese (≥ 40). We evaluated the effect of the management of labour on the need for Caesarean section using unconditional logistic regression models.

Results: Data were available for 11 922 women, of whom 2289 women had normal weight, 5663 were overweight, 3730 were obese, and 240 were morbidly obese. After adjustment for known confounding variables, increased BMI category was associated with an overall increase in the use of oxytocin and in the use of epidural analgesia, and with a decrease in use of forceps and vacuum extraction among second stage deliveries. 
Higher BMI was also found to be associated with earlier decisions to perform a Caesarean section in the second stage of labour. 
When adjusted for these differences in the management of labour, the increasing rate of Caesarean section observed with increasing BMI category was markedly attenuated (P less than 0.001). 
Conclusion: Women with an increased BMI are managed differently in labour than women of normal weight. This difference in management in part explains the increased rate of Caesarean section observed with higher BMI.
Aust N Z J Obstet Gynaecol. 2011 Apr;51(2):172-4. Impact of morbid obesity on the mode of delivery and obstetric outcome in nulliparous singleton pregnancy and the implications for rural maternity services. Green C, Shaker D.  PMID: 21466521
Obesity represents a rapidly emerging epidemic amongst pregnant women. Our study looks at the impact of morbid obesity on pregnant singleton nulliparous women in comparison with normal body mass index women. We conclude that morbid obesity is associated with a significantly higher risk of pre-existing medical conditions, developing antenatal complications, induction of labour, caesarean section and greater birth weight. However, there was no significant difference in caesarean section rates when adjusted for induction of labour. We also found no significant difference in length of hospital stay, postnatal complications and neonatal morbidity.



Monday, January 16, 2012

Increased Morbidity After Just One Cesarean

This study is about adverse outcomes in the next pregnancy after just one cesarean.  Women with only one prior cesarean were already at increased risk for anemia, placental abruption (where the placenta pulls away from the uterus before birth, cutting off nutrients and oxygen), uterine rupture, and hysterectomy.

Of course, the actual numerical risk of these complications is generally small, but it does represent an increased risk over women who first birth was vaginal, and that's an important point.

If 1 out of 3 women in the USA is having a baby via cesarean (and in some hospitals, the rate is more like 1 in 2 or more), that's an awful lot of potential risk being put onto women.  And that's after only one cesarean. Most women who have one cesarean will go on to have more with future children because VBAC is not an option in far too many hospitals.

When cesareans save lives, these risks are absolutely worth the trade-off.  When cesareans are used casually or for dubious indications, these trade-offs are much more ominous.

The authors' conclusion is that women who have cesareans need to be counseled about the possible increased risks in future pregnancies. This is true, but the importance of reducing these risks by avoiding that first cesarean whenever possible should also have been mentioned.

Recognizing that cesareans carry risks is an important part of the discussion of the public health implications of a high c-section rate.  



Am J Obstet Gynecol. 2011 Sep 24. [Epub ahead of print] Morbidity following primary cesarean delivery in the Danish National Birth Cohort. Jackson S, et al.   PMID: 22051815
Source: Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Cedars-Sinai Medical Center, Los Angeles, CA. 
OBJECTIVE: Cesarean delivery rates are on the rise in many countries, including the United States. There is mounting evidence that cesarean delivery is associated with adverse reproductive outcomes in subsequent pregnancies. The purpose of this article is to review those outcomes in a well-defined cohort of pregnant women.
STUDY DESIGN: In a cohort of primigravid women from the Danish National Birth Cohort with known baseline exposure characteristics, we stratified women by method of first delivery, vaginal or cesarean, and evaluated for appearance of adverse reproductive events in subsequent pregnancies.
RESULTS: After adjusting for age, body mass index, alcohol, smoking, and socioeconomic status, women who underwent cesarean delivery at first birth were at increased risk in their subsequent pregnancy for anemia (odds ratio [OR], 2.8; 95% confidence interval [CI], 2.3-3.4), placental abruption (OR, 2.3; 95% CI, 1.5-3.6), uterine rupture (OR, 268; 95% CI, 65.6-999), and hysterectomy (OR, 28.8; 95% CI, 3.1-263.8).
CONCLUSION: Women who deliver their first baby with a cesarean are at increased risk of adverse reproductive outcomes in subsequent pregnancies and should be counseled accordingly.

Monday, January 9, 2012

Need an Extra Layer for Warmth?

If you are a person of size and a "cold" person ─ that is, strongly affected by cold weather and in need of lots of extra layers during the wintertime ─ then you know how hard it can be to find those extra layers in our sizes.  So let's talk about that for a minute.

As frequent readers know, I have hypothyroidism.  It's well-treated with meds, my TSH is in my ideal range, and I'm much less symptomatic than I used to be, but that doesn't mean I am totally symptom-free.

One of the most striking symptoms that remains is how poorly I regulate my temperature.  Within a certain range of temps, I'm fine, but even slightly outside that narrow range and I'm really uncomfortable.  In particular, I am strongly affected by cold.  It really makes me absolutely miserable, I kid you not.

So I'm always looking for extra layers to help keep me warmer in the winter...but I am a bit claustrophobic and hate feeling suffocated by really thick or poufy layers.  And I don't tolerate itchy fabrics like wool very well either.  In addition, even when there's good-quality stuff available, it's usually not available in my size.  Most plus-sized stuff in the athletic brands goes up to 2x or maybe 3x, but I typically prefer a 4x because I like things quite roomy and comfortable.  So it's not easy to find something that suits my needs very well.

Junonia makes exercise and outdoorwear in extended sizes (4x, 5x, sometimes 6x). I've bought from them for years but their quality is spotty.  Sometimes I get something really great from them (so they are definitely worth checking out), but sometimes I've gotten some very mediocre stuff too.  Generally speaking, they don't seem to have the kind of quality and choice of really good outdoor stuff that I could get at REI if I were of average size, like the really high-tech insulation-against-cold fabrics or the ultra-light packable gear, etc.  And I really want the good stuff.

I am not overly outdoorsy because of my cold-weather intolerance but I do have times when I do outdoorsy stuff.  I like to take walks in my area, and we have been known to camp or hike. I also volunteer at my kids' school, which regularly has "farm days" (for environmental education), no matter what the weather is...raining, windy, snowing, sleeting, you name it. That can be pretty brutal.  So I definitely need some layers and good outerwear for these activities.

Even around the house at night, it gets a lot colder than I am comfortable with, but I'm not willing to crank up the heat for the whole house that far when I'm the only one really affected. So, given how cold I tend to be, I need some good-quality layers for lounging around or working at home. I'm looking for lightweight but very warm layers ─ in my size ─ that I can add and subtract as needed.

Last year, I discovered that Columbia Sportswear carries good-quality sports and cold-weather clothing/gear in plus sizes.  They have women's sizes up to 3x, but their men's sizes go up to 4x and sometimes 5x.  This gives more choices to those of us who need/prefer extended sizes. (The men's sizes also have an option for "tall" sizes if you need that. I, alas, am very far from needing that.)

It frustrates me to have to shop in the men's department in order to get really good-quality sports and outdoor clothing in my size, but hey, at least we have some choices, even if it's in menswear.  So last year I invested in a whole bunch of winter gear from Junonia and Columbia, and have been testing it this year to see what's best.

I've fallen in love with the following item and wanted to let you know about it before it's all gone:

http://www.columbia.com/Men%E2%80%99s-Mountain-Tech%E2%84%A2-1/2-Zip-%E2%80%94-Big/AX6565,default,pd.html#

It's a lightweight polyester half-zip sports shirt for wicking away moisture while running or biking.  However, I've found that it does an amazing job of keeping me warmer, much better than a wool sweater or a cardigan.  I just wear normal clothes underneath, and put this on top whenever I start feeling chilly.

That's usually enough for hanging around the house, doing chores, driving in the car or for short jaunts outside if the weather's not too bad.  For longer outside jaunts in nasty weather, I wear them for layering under my winter coat (the soft shell coat or the Bugaboo parka from Columbia) as needed.

Sometimes if I'm really cold I will put on two of these zip-up sports shirts.  They are so lightweight that I don't feel like the Stay-Puft Marshmallow Man, and they really do add a nice layer of extra warmth.  I haven't found this combination of warmth and thinness of fabric with any other product, so I wanted to be sure to let you know about these before they are all gone.

These little zip-up sport shirts have made a MAJOR difference for me in staying warmer in and out of the house.  I still have cold moments, but these have really helped. They come in several different colors and pack really well, so they'd be ideal for trips too.

I'm buying some more to have on-hand.  I was hoping they'd be on sale after the holidays, but no such luck. So they're not cheap....about $40.....but well worth it in my book!

If you need some more stay-warm options, you might want to check them out.