A comparison of orally administered misoprostol and membrane sweeping for labour induction in uncomplicated, singleton post-term pregnancies

Abstract

Objectives. This study assessed the efficacy of the two outpatient processes of single-dose 50 μg oral misoprostol (OM) and membrane sweeping (MS) on the outcome of labour induction and the possibility of reducing the need for hospital admission for cervical ripening/labour induction in uncomplicated post-term singleton pregnancies at a tertiary health institution in south-western Nigeria.

Methods. A total of 100 patients were equally randomised into the two groups between April 2007 and March 2010. Primary outcome measures were delivery within 48 hours after the start of induction and route of delivery. Secondary outcome measures were time interval from induction to onset of labour (latency period), time interval from start of induction to delivery (duration of labour), need for oxytocin augmentation, labour complications, Apgar scores at 1 and 5 minutes, and need for neonatal intensive care unit (NICU) admission.

Results. Both groups were similar at the baseline with regard to age, parity and days beyond 40 weeks’ gestation. There was a significantly shorter induction to onset of labour (latency) interval in the OM group, with a mean of 17.0 hours compared with 31.9 hours in the MS group (p=0.005), with 82.0% of the patients in the OM group in spontaneous labour within the latency period of 18 hours as opposed to 32.6% of the MS group (p<0.005). Forty-two patients in the OM group and 40 in the MS group had a vaginal delivery (84.0% v. 87.0%,
p=0.361), with 12 and 20 patients in the OM and MS groups, respectively, requiring oxytocin augmentation (p=0.023). The duration of labour was significantly shorter in the OM group, in which 78.6% of those who had a vaginal delivery achieved it within 9 hours, compared with 57.5% in the MS group (p=0.036). Overall, neonatal outcomes and need for NICU admission were similar and comparable in the two groups. On a preference scale, 43% of the women in the MS group felt positive about the intervention, compared with 92% of the women in the OM group.

Conclusion. The study demonstrated a shorter latency period, less need for oxytocin augmentation and shorter duration of labour in patients who received OM. The two induction agents were similar with regard to neonatal outcomes and need for NICU admission. Both showed good safety profiles for outpatient care, although further assessment of the safety profile with larger studies will be needed. More patients felt positive about the intervention in the OM group than in the MS group.