Our referral hospital advises repeat CS for women who will birth in less than 24 months from their last CS because of the increased risk of uterine rupture.

Can you point me to the research around this issue?

I find that not all hospitals have this belief, therefore is it valid?

In the past I have attended many successful VBAC, not all of which came after 2 yrs from the last CS.

Cheers

Judy

As it happens, I have the research at my fingertips. I've been working on a new edition of my first book, Obstetric Myths Versus Research Realities, this time with a co-author, Amy Romano. (BTW, Amy has a new blog for Lamaze, Science and Sensibility, that might interest you.) I finished the VBAC chapter a few months ago, and I have five studies reporting on scar rupture rates according to either interpregnancy or interdelivery interval. Studies differed in which measure they chose and the length of the shorter interval. Nonetheless, the scar rupture rate with the shorter interval ranged from 1.1% to 2.8%, or a 97% to 99% likelihood of an intact uterus. Interestingly, the studies at the two extremes both measured the same interval: an interdelivery interval of less than or equal to 24 months vs. greater than 24 months. This tells you that something else is affecting rates. That something is likely to be single- uterine suturing, induction of labor, or the two together.

-- Henci

Bujold E, Mehta SH, Bujold C, et al. Interdelivery interval and uterine rupture. Am J Obstet Gynecol 2002;187(5):1199-202.

Huang WH, Nakashima DK, Rumney PJ, et al. Interdelivery interval and the success of vaginal birth after cesarean delivery. Obstet Gynecol 2002;99(1):41-4.

Landon MB, Spong CY, Thom E, et al. Risk of uterine rupture with a trial of labor in women with multiple and single prior cesarean delivery. Obstet Gynecol 2006;108(1):12-20.

Shipp TD, Zelop CM, Repke JT, et al. Interdelivery interval and risk of symptomatic uterine rupture. Obstet Gynecol 2001;97(2):175-7.

Stamilio DM, DeFranco E, Pare E, et al. Short interpregnancy interval: risk of uterine rupture and complications of vaginal birth after cesarean delivery. Obstet Gynecol 2007;110(5):1075-82.

Thanks Henci.

I eagerly await your new version of your book, I lend my copy out to women who question the protocols that I must bring up with them even if I don't agree. I have to obey protocol but the women know they don't have to follow protocol themselves.

Have you got around to comparing the statistical risk of uterine rupture in a woman in spontaneous labour, one previouse CS with double layer closure and no other risk factors, to the risks of booked CS to eliminate the risk of rupture?

Cheers

Judy

I have four studies of truly elective repeat cesarean in which the cumulative scar rupture rate was 0.2 per 1000. I can't quite nail down the rate in your optimal-for-VBAC population, but it should be 4 per 1000 or less. Four per 1000 was the rate in the big Landon 2004 study in women with spontaneous labor onset who labored without oxytocin augmentation. In the birth center VBAC study, the rate in women with one prior cesarean who had not reached 42 weeks gestation was 2 per 1000. These women, too, would have had spontaneous onset and no augmentation. Put positively, the women you describe should have a 99.6% to 99.8% odds of an intact uterus. Moreover, in the few women who had the scar give way, except for rare cases, the only adverse outcome would be an urgent repeat cesarean. Against this, must be considered the potential harms of accumulating cesareans for the mother, baby, and future pregnancies. 

Thank you for your enthusiasm about the new edition.

-- Henci 

Blanchette H, Blanchette M, McCabe J, et al. Is vaginal birth after cesarean safe? Experience at a community hospital. Am J Obstet Gynecol 2001;184(7):1478-84; discussion 84-7.

Landon MB, Hauth JC, Leveno KJ, et al. Maternal and perinatal outcomes associated with a trial of labor after prior cesarean delivery. N Engl J Med 2004;351(25):2581-9.

Lieberman E, Ernst EK, Rooks JP, et al. Results of the national study of vaginal birth after cesarean in birth centers. Obstet Gynecol 2004;104(5 Pt 1):933-42.

Loebel G, Zelop CM, Egan JF, et al. Maternal and neonatal morbidity after elective repeat Cesarean delivery versus a trial of labor after previous Cesarean delivery in a community teaching hospital. J Matern Fetal Neonatal Med 2004;15(4):243-6.

McMahon MJ, Luther ER, Bowes WA, Jr., et al. Comparison of a trial of labor with an elective second cesarean section. N Engl J Med 1996;335(10):689-95.

Spong CY, Landon MB, Gilbert S, et al. Risk of uterine rupture and adverse perinatal outcome at term after cesarean delivery. Obstet Gynecol 2007;110(4):801-7.

Henci,

The specific woman I was after the info for had an empowering VBAC a couple of days ago. As well as the books I have, I downloaded as many of the above articles as I could and gave them to the couple to read. The reading they did and the support I gave had such a great outcome, her grin is a mile wide.

Cheers

Judy

I love happy endings! :-D

-- Henci