VBAC research
Vaginal Birth After Cesarean Predicts Success in Subsequent Vaginal Delivery
Reuters Health Information 2008. C 2008 Reuters Ltd.
NEW YORK (Reuters Health) Feb 05 - Women who have had one successful vaginal birth after cesarean delivery (VBAC) are even more likely to succeed during subsequent trials of VBAC, results of a prospective, multicenter trial indicate.
Dr. Brian M. Mercer, from Case Western Reserve University in Cleveland, Ohio, and colleagues previously reported an overall VBAC success rate of 73% and uterine rupture rate of 0.7% for women with a prior low transverse
uterine incision. However, the effect of a prior VBAC on the risk of uterine rupture has not been clear.
For their current report in the February issue of Obstetrics & Gynecology, Dr. Mercer’s group examined the impact of prior VBAC on outcomes of attempted VBAC in subsequent pregnancies in 13,532 women included in a
19-center registry.
For 9012 women (67%), this was their first VBAC; 2900 women (21%) had a history of one prior VBAC, 1058 (7.8%) had a history of two, 371 (2.7%) had a history of three, and 191 (1.4%) had a history of four or more VBACs.
The frequency of VBAC success rose with increasing number of prior VBACs, Dr. Mercer’s team reports, from 63% with no prior VBACs to 88% for those with one and 91% for those with two or more prior VBACs.
The corresponding incidence of uterine rupture declined from 0.87% to 0.45% and 0.43%.
The rates of other complications — uterine dehiscence, surgical complications, need for transfusions, endometritis, and hypoxic ischemic encephalopathy — followed similar patterns with increasing number of prior
VBACs.
In contrast, the investigators note, repeated cesarean deliveries are associated with higher risks of placenta accreta, trauma to maternal internal organs, and more frequent hysterectomies and transfusions.
"Women planning large families … should be reassured by the increasing success rates and decreasing risks associated with VBAC attempts in successive pregnancies," Dr. Mercer and his associates conclude.
Obstet Gynecol 2008;111:285-291.
