Oxytocin vs Prostaglandins for Labor Induction of Women With an Unfavorable Cervix After 24h of Cervical Ripening

Twenty-two percent of deliveries in France are induced. In cases where labor is induced and cervix is unfavorable, cervical ripening prior oxytocin administration is advised in order to reduce the risk of cesarean delivery. Cervical ripening agents, pharmacological (prostaglandins) or mechanical are administered during 24 hours. After 24 hours, most women will be either delivered or in labor but 25% of women will require further induction of labor. For 16% of women who undergo cervical ripening, whatever the cervical ripening method, the cervix remains unchanged after 24 hours. The management of these women is not consensual and depends on the maternity unit where women are cared for. In some units, women are admitted into labor ward for induction of labor with oxytocin. Elsewhere cervical ripening is repeated in order to obtain a favorable cervix and to reduce the risk of caesarean delivery.

This study seeks to identify the most appropriate strategy for the management of women with an unfavorable cervix after 24 hours of cervical ripening, a strategy which would be associated with the lowest maternal and perinatal morbidity but also with the best maternal satisfaction. Because both strategies are practiced in France, the trial would compare: induction of labor with oxytocin and repeated cervical ripening. The policy of induction of labor with oxytocin, being the simpler strategy, would be acceptable if it did not lead to a substantially proportion of women with caesarean deliveries compared with a second cervical ripening. This multicenter non inferiority randomized trial will recruit women with an unfavorable cervix (bishop score ≤ 6) after 24 hours of cervical ripening (pharmacological or mechanical) and randomize them to either induction of labor with oxytocin or to a second cervical ripening with prostaglandins. The aim is to show that repeating cervical ripening is an unnecessary procedure. And more specifically that oxytocin administration is not associated with a higher caesarean delivery rate and that it reduces the time to delivery in comparison with cervical ripening with prostaglandins.

Inclusion criteria

• Pregnant woman
• ≥ 18 years old
• With a singleton cephalic pregnancy
• ≥37+0 weeks of gestation
• Gestational age estimated from the first trimester ultrasound (realized between 11+0 and 13+6 weeks of gestation)
• With a medical indication of labor with a previous pharmacological or mechanical cervical ripening of 24 hours
• Bishop score ≤ 6 at inclusion (unfavorable cervix)
• French health insurance policy holder
• Written informed consent

Exclusion criteria

• Any measures of legal protection
• Prior caesarean section or uterine scar
• Contra-indications to a vaginal delivery
• Foetus with suspected severe congenital abnormalities
• Pathological foetal heart rate
• Contra-indications to ANGUSTA® (oral misoprostol, cervical ripening agent)
• Contra-indications to PROPESS® (vaginal slow releasing system of dinoprostone, cervical ripening agent)
• Contra-indications to PROSTINE® (vaginal gel of dinoprostone, cervical ripening agent)
• Contra-indications for using oxytocin
• Woman in labor