RANDOMIZED TRIAL COMPARING A POLICY OF EARLY WITH SELECTIVE AMNIOTOMYIN UNCOMPLICATED LABOR AT TERM

Objective To compare two management policies: rupture of the fetal mem branes when women are in normal labour or leave them intact as long as feasible. Setting The labour ward of a city university hospital. Desi gn Automated randomised clinical trial. Participants 1540 women in unc omplicated term labour. Data on labour duration, blood loss, oxytocin use and fetal condition were collected from 1132 women. Some data from nulliparous women has been presented earlier by the UK Amniotomy Grou p. Main outcome measures Duration of labour, Apgar score, fetal morbid ity and maternal morbidity including perineal injury, mode of delivery , epidural rates and the total number of vaginal examinations in the f irst stage of labour after amniotomy. Interventions Amniotomy at the n ext vaginal examination or amniotomy only if indicated. The median cer vical dilatation at membrane rupture was 2 cm greater in the first gro up. Results A policy of routine amniotomy in labour had no measurable advantage over selective amniotomy for parous women (difference = 4 mi n) but shortened labour in nulliparous women by 1 h (Mann-Whitney U te st: P < 0.05). There was a suggestion of a higher caesarean section ra te (OR 1.9; 95% CI 0.9-3.5), and there were more vaginal examinations after membrane rupture in the group allocated routine amniotomy. There were no measurable differences in oxytocin use, fetal condition at bi rth, retained placenta rates, blood loss, pain or analgesia requiremen ts. Conclusion Routine amniotomy may shorten the first labour but not subsequent ones. There is a suggestion that routine surgical interfere nce may be harmful by increasing the risk of caesarean section, and th is agrees with data from other trials (common odds ratio 1.2; 95% CI 0 .92-1.6).