Effects of early augmentation of labour with amniotomy and oxytocin in nulliparous women: a meta-analysis

Abstract

Objectives: To estimate the effects among nulliparae of early augmentation with amniotomy and oxytocin on caesarean delivery, and on other indicators of maternal and neonatal morbidity including transfusion. Apgar score < 7 at 5 minutes, and admission to the special care nursery.

Design: Meta-analysis.

Methods: Published studies were identified through manual and computerised searches. Two unpublished studies were identified through direct communication with the investigators. Twelve trials were identified which compared a policy of early labour augmentation including amniotomy followed by oxytocin with a less active form of management. Two methodologically unacceptable studies were excluded. Studies were grouped according to whether they admitted only women with abnormal progress (therapy trials: n = 3) or accepted women with normal labour (prevention trials: n = 7).

Results: Unstratified analysis did not provide support for the hypothesis that early augmentation reduces the risk of caesarean section (typical odds ratio [OR] 0.9; 95% CI 0.7-1.1). The typical odds ratio for prevention trials was similar to that obtained in the unstratified analysis (typical OR 0.9, 95% CI 0.7-1.2). Although only a small number of women have been randomised in therapy trials, a trend toward a reduction in the rate of caesarean section with early intervention was seen in this group (typical OR 0.6, 95% CI 0.2-1.4).

Conclusions: Early augmentation does not appear to provide benefit over a more conservative form of management in the context of care of nulliparous women with mild delays in the progress of labour. In the context of established delay in labour, an active policy of augmentation may reduce the risk of caesarean section. However, only three small trials have been performed in this context, and they do not have adequate power to allow firm conclusions to be drawn.