Outcomes of labours augmented with oxytocin

To highlight the differences in mode of delivery between women augmented with intravenous oxytocin because of failure to progress in labour with those who labour without the need for augmentation.

An incidence study over a 5-year-period in a tertiary referral hospital comparing 1097 nulliparous women who were augmented in labour with 2745 nulliparous women who did not need augmentation. Only labours of spontaneous onset in the pregnancies of women at term were studied. The incidence of pregnancy outcomes were assessed by presenting estimates of relative risk (RR) and their 95% confidence intervals (CI).

Only 51.1% of women who received augmentation achieved a normal vaginal delivery compared with 76.5% of women who did not need augmentation (RR 0.67; CI 0.63-0.71). Contributory factors to this disparity included a greater number of Caesarean sections (14.4% versus 6.6%; RR 2.18 CI 1.74-2.67), forcep deliveries (12.8% versus 5.3%; RR 2.41 CI 1.93-3.01) and ventouse deliveries (21.7% versus 11.5%; RR 1.89 CI 1.62-2.21) being performed among augmented labours as compared to normal progressive labours.

Significant improvements in the management of labours which fail to progress are needed if normal vaginal delivery rates are to approach those seen in labours which progress without the need for augmentation.