Induction of Labour: Does Internal Tocography Result in Better Obstetric Outcome than External Tocography

A prospective randomized study was undertaken to evaluate the benefit of intrauterine catheters in induced labour. Two hundred and thirty nine women who had induced labour were studied. The patients in one group had intrauterine catheters inserted and oxytocin was titrated to achieve the 75th percentile of uterine activity observed in spontaneous normal labour according to parity. Contractions were assessed by external tocography in the other group and oxytocin was titrated to achieve 6 to 7 contractions per 15 minutes each lasting > 40 seconds. Mean maximum dose of oxytocin, mode of delivery, Apgar score < 7 at 5 minutes, cord arterial blood pH < 7.15 and admission to neonatal intensive care unit did not differ significantly in the 2 groups. In conclusion, women who had intrauterine catheters did not have a shorter duration of labour, lower dose of oxytocin, fewer operative deliveries or fewer babies in poor condition at birth compared with those who had external tocography in induced labour.