Concurrent oxytocin with dinoprostone pessary versus dinoprostone pessary in labour induction of nulliparas with an unfavourable cervix: a randomised placebo-controlled trial

Abstract

Objective: To compare concurrent oxytocin with dinoprostone pessary versus dinoprostone pessary in labour induction for nulliparas with an unfavourable cervix.

Design: A randomised double-blind study.

Setting: University Malaya Medical Centre, Malaysia.

Population: Nulliparas at term with intact membranes, Bishop score < or = 6 and admitted for labour induction.

Methods: All women received 3 mg dinoprostone pessary for labour induction. Those randomised to the oxytocin arm received oxytocin infusion started at 1 micro/minute and doubled every 30 minutes to a maximum 16 micro/minute. Women assigned to placebo received identical volume of saline infusion. After 6 hours, infusion was stopped and vaginal reassessment performed to guide further management.

Main outcome measures: Primary outcome was vaginal delivery within 24 hours.

Results: Concurrent oxytocin infusion with dinoprostone pessary did not significantly increase vaginal delivery rate within 24 hours (48.6 versus 35.9%; P = 0.07, relative risk [RR] 1.4 [95% CI 1.0-1.9]). It reduced the requirement for repeat dinoprostone (37.1 versus 61.2%; P = 0.001, RR 0.61 [95% CI 0.45-0.81]) and improved maternal satisfaction with the birth process (median score of 3 versus 5 on a 10-point visual analogue scale, P = 0.007). Caesarean rates were not different (41.9 versus 44.7%, P = 0.52).

Conclusions: Labour induction with concurrent oxytocin infusion and vaginal dinoprostone could be considered for nulliparas with an unfavourable cervix. Larger studies are needed.