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
Thank you for your
enthusiasm about the new edition.
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
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.