1 and 2 layer uterine closing after Cesarean surgery & increased complications for VBAC mothers after 1-layer closing

Reprint of Email from 
Ina May Gaskin, CPM

On 1-layer closure: here's what brought my attention to this subject. Dr. Kurt Bernischke, a pathologist and author of Pathology of the Human Placenta, gave a talk at the National Association of Childbearing Centers in fall, 1999. He had a long career as pathologist in Boston and told me that he had never seen a case of placenta percreta there. He moved to San Diego and practiced there for 3 years and saw about 10 placentas percreta each year. On inquiring what differences in surgical technique (since all of the women involved had had previous c-sections), he said the difference was 1-layer suturing in San Diego and traditional 2-layer suturing in Boston.

On hearing this, I remembered a couple of obstetricians who had a baby with us 8 years ago. They told me there had been a couple of maternal deaths at the hospital where they were residents; the women bled to death from placenta percreta. When I told them about Bernischke's worry, they said they had been urged to close with 1-layer by some of their profs, and they did it albeit with some misgivings. They said the older profs tended to recommend 2-layer. Anyway, they immediately changed to 1-layer when they heard of Bernischke's comments. A few weeks later, a woman died at the hospital where they now work - same cause: placenta percreta following a previous 1-layer closure. She came in labor at 20 weeks, delivered in the ER and bled to death in 8 minutes.
I went to the literature and found almost nothing there. Cochrane Library lists 2 studies that fit their criteria - a total of 133 women who had 1-layer have been studied. Nevertheless, tens of thousands of US women (at least) have had 1-layer without knowing this is a big, ad hoc experiment.
Yes, I know that 2-layer could be considered experimental, too, but at least, this is this method that the extremely rare incidence of placenta percreta is based upon (1 in 12,500 births, according to Gabbe, Niebyl and Simpson). Whatever happened to evidence-based practice?

My partners and I will continue to attend out-of-hospital VBACs, but we don't want to end up with a percreta. An ultrasound to make sure the placenta isn't lying over the previous scar seems warranted, unless we can definitely hear it in the fundus.

We were feeling okay with this protocol until we heard about a new study that found a 5X higher rupture rate with 1-layer. A 3.3% rate of rupture is pretty high for a home birth practice, we think. At the very least, women need to be informed of the higher risk that this Montreal study showed.

Here's the abstract:
Uterine rupture during a trial of labor after a one- versus two-layer closure of a low transverse cesarean.
Emmanuel Bujold, Camille Bujold, Robert J. Gauthier; Ste-Justine Hospital,
University of Montreal, Obstetrics and Gynecology, Montreal, Quebec.
Objective: To determine whether there is a difference in the rate of symptomatic uterine rupture during a trial of labor (TOL) in women who had
a 1-versus a 2-layer closure of a low transverse cesarean section (LTCS).
Study Design: Medical records of all women who had a TOL after LTCS between 1990 and 2000, in our instutution were reviewed. The rates of uterine rupture were compared between women who had a 1-layer at their previous cesarean section with those who had a 2-layer closure. Multivariate logistic regression analyses were used to control for maternal age, birth weight, gestational age, use of epidural, induction of labor, oxytocin augmentation, prior vaginal delivery and prior cesarean section for arrest disorders.

Results: There were 1649 women included in the study.  Women with a previous 1-layer closure (n=398) had a rate of uterine rupture of 3.3%, whereas those with a previous 2-layer closure (n=1251) had a rate of uterine rupture of 0.6% (p<.001).  The odds ratio for uterine rupture in women with a 1-layer closure was 5.2 (95% confidence interval, 2.1 to 12.8).

Conclusion: A 1-layer closure at the previous LTCS is associated with a 5-fold greater risk of uterine rupture during a trial of labor for the subsequent delivery than a 2-layer closure.
Abstracts of the 2001 21st Annual Meeting of the Society for Maternal-Fetal Medicine. American Journal of Obstetrics and Gynecology (supplement)
184(1):S18, 2001.
I've been looking into this subject for about a year now and have begun a correspondence with K. Bernischke. He's currently the Director of the San Diego Zoo, and since I had to be in San Diego last week, I visited him there. Several times he repeated that they had 10 cases per year. According to what he said on the NACC tape, he showed the San Diego ob.gyn society these results but that they shrugged it off. He gave me the name of another
pathologist, who claims a similar experience, but I haven't managed to contact her yet.
Recent articles in OBG Management and Contemporary Ob.Gyn have tauted the new method as time- and suture-saving, and possibly associated with less post-operative pain, blood loss, maybe fewer adhesions. But these are all maybes, and the first two advantages don't accrue so much to the women as to their HMOs. The economic motive for promoting 1-layer is obvious. What is less easy to see is why a change in technique has been necessary. Is there a real public health advantage? I submit that Bernischke's evidence is at least as strong as the two tiny studies reviewed by the Cochrane Library - even though his hasn't yet been published. Maybe not enough for a medical journal, but definitely the kind of thing I want to be aware of as a midwife who attends o-o-h VBACs. On the basis of what I know, if I were still in my childbearing years and needed a c-section, I'd want a 2-layer closure.
Bernischke may be only one of the experts whose opinion we should consider here, but his experience should not be taken lightly, I think. Having met him and talked to him for an hour, I found him to be extremely credible.
Seems like more retrospective studies are needed at different centers where both 1-layer and 2-layer closure have been done over the last few years.
Meanwhile, I'm for informing women that this surgical technique should be considered experimental. I'm still amazed that so little careful research has been done, considering what a big shift in practice this has been. How long has this been going on?
Ina May Gaskin, CPM