Randomised trial of one versus two doses of prostaglandin E2 for induction of labour: 1. Clinical outcome

Abstract

Objective: To compare the outcome of induction of labour using a single versus two doses of prostaglandin E2 vaginal gel.

Design: Prospective randomised trial comparing a single dose of prostaglandin E2 2 mg vaginal gel in the evening with two doses of prostaglandin E2 (2 mg), the second being given after six hours if labour had not started or the cervix was still unripe. Amniotomy and oxytocin titration were performed when necessary for both protocols. Nulliparae and multiparae were analysed separately by treatment intention.

Setting: A maternity unit in a district general hospital annually delivering > 6000 women.

Participants: Nine-hundred and ninety-five women with viable singleton pregnancies and cephalic presentation at term without previous history of caesarean section who were advised to have labour induced with prostaglandins.

Main outcome measures: Need for formal amniotomy and oxytocin augmentation, use of epidural analgesia, rate of intrapartum interventions, mode of delivery and neonatal condition at birth.

Results: For multiparae two prostaglandin doses resulted in a significant reduction in the need for formal amniotomy (15% vs 30%) and oxytocin augmentation (28% vs 38%) compared with those receiving a single dose; there was no significant difference for nulliparae. Other interventions during labour, length of labour, and mode of delivery were similar in both protocols. Failed induction occurred only in nulliparae and was similar in both protocols (1%). There was no discernible difference in fetal or neonatal outcome although passage of meconium was more common in labour if two doses had been given, as was neonatal admission to the special care baby unit.

Conclusions: There was little clinical benefit from inducing labour with two doses of prostaglandin E2 at a six-hour interval, compared with a single dose. There may be financial advantages with a two-dose regimen.