Limited data exists regarding the consequences of operative vaginal delivery(OVD) on subsequent pregnancies. Our aim was to assess pregnancy outcome and mode of delivery in women with a previous OVD.
A case control study of all nulliparous women who underwent OVD in a single tertiary center during 1993-2006 (N=4153). The control group included nulliparous women who underwent spontaneous vaginal delivery(SVD) during this time period in a 2:1 ratio, matched by maternal age and gestational age at delivery (N=8306). The outcome of subsequent delivery for women in the study and control groups was compared (N=1396 and N=2591,respectively). Women with multiple-gestations, non-vertex presentations, or any other contraindications for vaginal delivery were excluded.
1)Out of 83,351 deliveries during the study period, 5,120 (6.1%) were by OVD, of which 81% involved nulliparous women(N=4153). 2) Women with a previous OVD were at increased risk for recurrent OVD (OR=3.9, 95%-CI 2.5-5.9) and CS (OR=1.9, 95%-CI 1.5-2.5) on subsequent pregnancy. 2) Prolonged 2nd stage was the most common indication for recurrent OVD (80%)in women with a previous OVD, compared with only 34% in women with a previous SVD. 3)The risk of intrapartum-neonatal trauma(1.5% vs. 0.6%) and 3rd-4th-degree lacerations (0.7% vs. 0.2%) was significantly higher in the group of women with a previous OVD (p<0.01). 4)The following factors were associated with increased risk for recurrent OVD: failed vacuum extraction (OR=2.8, 95%-CI 1.4-5.8), prolonged 2nd-stage as the indication for OVD (OR=2.1, 95%-CI 1.2-3.6) on the index pregnancy, time from first pregnancy >3y (OR=3.8, 95%-CI 1.2-12.5), higher fetal-weight on subsequent pregnancy (OR=2.1, 95%-CI 1.2-3.3), and persistent occipito-posterior position (OR=13.8, 95%-CI 4.8-21.2) and the use of epidural (OR=1.8, 95%-CI 1.1-3.3) during subsequent pregnancy.
Nulliparous women undergoing OVD are at increased risk for recurrent OVD, cesarean section, perineal trauma and neonatal trauma upon their subsequent pregnancy.
© 2008 Mosby, Inc. Published by Elsevier Inc. All rights reserved.