A multicentre randomised trial of amniotomy in spontaneous first labour at term. The UK Amniotomy Group

Abstract

Objective: To measure the effect of a policy of routine amniotomy on nulliparous labour.

Design: A multicentre randomised controlled trial.

Subjects: One thousand four hundred and sixty-three nulliparous women in spontaneous labour at term with intact membranes and a single cephalic fetus.

Interventions: To have the membranes ruptured routinely early in labour or left intact for as long as possible.

Main outcome measures: Duration of labour, operative and instrumental delivery rates, use of analgesia, perinatal death, neonatal convulsions and admission to special care.

Results: Median duration of labour was 8.4 h in the early rupture group and 9.4 h in the late group. There was no difference in caesarean section, typical odds ratio (OR) 1.1, 95% CI 0.65-1.8; operative vaginal delivery, OR 1.1, 95% CI 0.83-1.5; use of epidural/spinal, OR 0.92 95% CI 0.72-1.2; use of pethidine, OR 1.0, 95% CI 0.79-1.4; neither method of analgesia, OR 0.96, 95% CI 0.68-1.3; blood transfusion, OR 0.71, 95% CI 0.28-1.8. There was no effect on fetal intubation, OR 1.40 (95% CI 0.78-2.5); admission special care, OR 1.28 (95% CI 0.65-2.5). One fetus in the early amniotomy group had neonatal convulsions, but there were no perinatal deaths.