A randomised controlled trial of early versus delayed oxytocin augmentation to treat primary dysfunctional labour in nulliparous women

Abstract

Background: Oxytocin is widely used to speed up slow labour, especially in nulliparous women, but randomised trials, apart from one reported only in abstract, have been too small to exclude important effects.

Objective: To test the hypothesis that early use of oxytocin reduces the need for caesarean delivery.

Design: A randomised controlled trial.

Setting: Twelve obstetric units within the Northern and Yorkshire regions in the North East of England.

Participants: A total of 412 low-risk nulliparous women in spontaneous labour at term, who had been diagnosed with primary dysfunctional labour were recruited from January 1999 to December 2001.

Intervention: Immediate oxytocin administration (active group) or oxytocin withheld for up to 8 hours (conservative group).

Main outcome measures: Caesarean section and operative vaginal delivery rates. The length of labour measured from the time of randomisation to delivery. The rate of maternal Edinburgh Postnatal Depression Scale (EPDS) greater than 12 (major depression) within 48 hours of delivery.

Results: The caesarean section rates were 13.5% active versus 13.7% controls (OR 0.98, 95% CI 0.6-1.7). Operative delivery, 24.5% versus 30.9% (OR 0.73, 95% CI 0.5-1.1). The median (interquartile range) randomisation to delivery interval in the active group was 5 hours 52 minutes (3:57-8:28) and in the conservative group 9 hours 8 minutes (5:06-13:16) (P < 0.001). The rate of EPDS >12 was 20% in the active arm versus 15% among controls (OR 1.26, 95% CI 0.7-2.2). There was one perinatal death in each group and no major differences in perinatal outcomes.

Conclusions: Among nulliparous women with primary dysfunctional labour, early use of oxytocin does not reduce caesarean section or short-term postnatal depression. However, it shortens labour considerably and may reduce operative vaginal deliveries.