Vaginal birth after cesarean delivery - Clinical Briefs

Author: Carrie Morantz, Brian Torrey
Date: March 1, 2004

The risk of uterine rupture from vaginal birth after cesarean delivery is relatively low, according to findings from the Agency for Healthcare Research and Quality (AHRQ). "Vaginal Birth After Cesarean" is available online at http://www.ahrq. gov/clinic/epcsums/vbacsum.htm.

Nearly 23 percent of births in the United States in 2000 occurred by cesarean delivery; this is the highest rate reported since data collection began in 1989. The rate of vaginal deliveries in women with previous cesarean deliveries decreased 27 percent from 1996 to 2000.

A meta-analysis by the AHRQ found that rates of vaginal delivery in women with a previous cesarean delivery who attempt a trial of labor range from 60 to 82 percent. Although data on the effects of labor induction and augmentation are limited, oxytocin use is associated with a 10 percent reduction in the likelihood of vaginal delivery.

A randomized controlled trial showed that radiographic pelvimetry is not able to reliably predict the route of delivery. Imaging studies that combine measurements of the pelvis and fetus show promising results but are limited by their failure to control for confounding factors.

Maternal mortality rates do not differ between women who attempt labor and women who choose to undergo a repeat cesarean delivery, and evidence suggests that hysterectomy rates also do not differ between the groups. Infection rates are higher in women who have cesarean deliveries; evidence is inconsistent about the effects of labor induction on infection rates. The risk of perinatal death in infants of women attempting labor is unclear, and there is insufficient evidence to make conclusions about the effect of route of delivery on Apgar score and respiratory comorbidity.

The rate of asymptomatic uterine rupture is equal in women attempting labor and women who choose a repeat cesarean delivery. However, symptomatic uterine rupture is significantly more common in women attempting labor. Based on severity and frequency of symptomatic uterine rupture, the risk of perinatal death from rupture of a uterine scar is 1.5 per 10,000; the risk of maternal hysterectomy is 4.8 per 10,000.

COPYRIGHT 2004 American Academy of Family PhysiciansCOPYRIGHT 2004 Gale Group

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