OBJECTIVE: The objective of this study was to evaluate the preterm birth rate in a subsequent pregnancy in women who had undergone term induction with a Foley catheter in comparison to induction with prostaglandins.
METHODS: This was a follow-up study of two large randomized controlled trials. In the original trials (PROBAAT-1 and PROBAAT-2), women with a term, singleton pregnancy in cephalic presentation with an indication for labor induction were randomized to either a 30cc Foley catheter or prostaglandins (i.e. vaginal prostaglandin E2 in PROBAAT 1 and oral misoprostol in PROBAAT 2). The main outcome measures were preterm birth <37 weeks gestation and preterm birth <34 weeks gestation. Data were collected from hospital charts on subsequent pregnancies from hospitals participating in this follow-up study.
RESULTS: 14 hospitals agreed to participate in this follow-up study. Of the 1142 eligible women, 162 women (14%) were lost to follow-up. Of the 572 women randomized to a Foley catheter, 251 women had a subsequent pregnancy beyond 16 weeks gestation, versus 258 women of the 570 women who received prostaglandins. There were no differences in baseline characteristics. The overall preterm birth rate was 9/251 (3.6%) in the Foley catheter group versus 10/258 (3.9%) in the prostaglandin group (RR 0.93; 95%CI 0.38-2.24), with spontaneous preterm birth rates of 5/251 (2.0%) versus 5/258 (1.9%) respectively (RR 1.03, 95%CI 0.30-3.51).
CONCLUSIONS: In women with a singleton term pregnancy, induction of labor with a 30cc Foley catheter is not associated with an increased risk of preterm birth in a subsequent pregnancy as compared to induction of labor with prostaglandins. This article is protected by copyright. All rights reserved.
- cervical ripening
- Foley catheter
- induction of labor
- preterm birth