Effectiveness and safety of high dose oxytocin for augmentation of labour in nulliparous women

Objective: To compare high and low starting dose of oxytocin infusion for effectiveness and safety in augmentation of labour in nulliparous women. Design: An open randomised controlled clinical trial. Setting: Harare Maternity Hospital, Zimbabwe. Subjects: 258 nulliparous women, with spontaneous onset of labour, who required augmentation. Main Outcomes Measures: Duration of augmentation, mode of delivery, maternal and neonatal complications. Interventions: Women were randomly allocated to either low dose (starting at 4 mIU/minute) or high dose (starting at 10mIU/minute) oxytocin group. Results: Of the 258 women enrolled, 133 were randomized to the low and 125 to the high starting oxytocin dose groups. The groups were comparable for maternal and gestational age. There was no difference in mean cervical dilatation before augmentation of labour; six cm in both groups (p=0.167). The mean augmentation to delivery interval was shorter in the high dose group, 218 versus 326 minutes (p< 0.001). There was no difference in the mode of delivery and fetal outcome in terms of birthweight, five minute Apgar score, admission to neonatal unit and perinatal death. Conclusion: A high starting dose of oxytocin infusion is as safe but more effective for augmentation of labour in nulliparous women, compared to a low starting dose.