Effectiveness and Safety of 2-Hourly 20 MCG Oral Misoprostol Solution Compared to Standard Intravenous Oxytocin in Labour Induction Due to Pre-Labour Rupture of Membranes at Term: A Randomised Clinical Trial at Kenyatta National Hospital
AbstractBackground: Pre-labour rupture of membranes (PROM) at term is a common event whose management varies from centre to centre. The practice at the Kenyatta National Hospital (KNH) for patients with PROM at term is to initiate delivery of the patient soon on admission with intravenous oxytocin, if there are no contraindications to vaginal delivery. However, in PROM at term, if the cervix is not ripe,vaginal administration of prostaglandin pessaries for cervical ripening is not possible when there is active draining of liquor, thus use of intravenous oxytocin may take a very long time or fail all together. Oral misoprostol at low doses has been found to be a safe and effective agent for labour induction in numerous studies carried out in the developed world, where there are better resources for monitoring of labour. None of the studies has been carried out in Kenya,
a limited resource country. Therefore, there is a need to determine the effectiveness and safety of oral misoprostol solution at the KNH, a limited resource set up.
Objective: To determine the effectiveness and safety of 2-hourly 20 mcg oral misoprostol solution compared to the standard intravenous oxytocinin labour induction in mothers with pre-labour rupture of membranes at term at the Kenyatta National Hospital.
Design: An unblinded randomised clinical trial.
Setting: Kenyatta National Hospital Labour Ward Unit.
Participants: Eighty three pregnant women with pre-labour rupture of membranes at term without an indication for Caeserian section were consented and randomised for labour induction with either oral misoprostol at a dose of 20mcg 2-hourly up to a maximum of 4-doses, or with intravenous oxytocin according to the WHO protocol.
Main outcome measures: Induction to delivery interval; maternal complications and early neonatal outcomes.
Results: The overall induction success rates in the misoprostol arm was 81% versus 83% in the oxytocin arm (P=0.447). The mean induction to vaginal delivery interval in the misoprostol arm was 8.4 hours as compared to 9.45 hours in the oxytocin arm (P=0.116). The induction to active labour interval was similar in the two study arms. The mean induction to active labour in the misoprostol arm was 4.02 hours as versus 4.51 hours in the oxytocin arm (P=0.223 ). Two women who had failed induction with misoprostol were augmented with oxytocin and delivered vaginally. The Caesarean section rates were 19% in the misoprostol arm and 17% in the oxytocin arm (P=0.447), which was not statistically significant. The maternal outcomes were similar in the two study arms. Four women had tachysystole in the misoprostol arm, compared to three in the oxytocin arm (P=0.253). In the misoprostol arm two women had hypertonus compared to three in the oxytocin arm (P=0.322).There was one case of hyperstimulation in the misoprostol arm and two in in the oxytocin arm. There were no differences in the foetal/ neonatal outcomes. No baby had an Apgar score of less than seven at one or five minutes. No baby was admitted to the New Born Unit in either of the two arms. There was no case of a still birth in either of the study arms. There was no significant difference in the passage of meconium between the two arms, 39% in the misoprostol arm and 35.7% in the oxytocin arm (P=0.755). The passage of meconium did not impact on the neonatal outcomes.
Conclusion: Oral misoprostol solution 20mcg 2-hourly is as safe and effective as the standard intravenous oxytocin for labour induction in women presenting with prelabour rupture of membranes at term at the Kenyatta National Hospital.