Slow-release vaginal insert of misoprostol versus orally administrated solution of misoprostol for the induction of labour in primiparous term pregnant women: a randomised controlled trial

Abstract

Objective: To compare the World Health Organization (WHO) recommended orally administrated dosage of misoprostol (25 μg) with a vaginal slow-release (7 μg/hour) insert of misoprostol regarding time from induction to delivery and safety of the method.

Design: Open label, Randomised controlled trial (RCT).

Setting: Delivery ward at a secondary referral hospital in Stockholm, Sweden, from 1 October 2016 to 21 February 2018.

Population: One hundred and ninety-six primiparous women with singletons in cephalic presentation at ≥37 weeks of gestation and with a Bishop score of ≤4.

Methods: Women were randomised to an oral solution of misoprostol (Cytotec^® n = 99) or vaginal slow-release misoprostol (Misodel^® [MVI] n = 97).

Main outcome measures: Primary outcome: time from induction to vaginal delivery.

Secondary outcomes: mode of delivery; proportion of vaginal deliveries within 24 hours (VD24); neonates with an Apgar score of <7 at 5 minutes; pH < 7.10; postpartum haemorrhage (PPH) of >1000 ml; hyperstimulation; and women's delivery experience (VAS).

Results: There was no difference in the time to delivery [corrected] (median 21.1 hours in the MVI group and 23.2 hours in the oral group; Kaplan-Mayer log rank P = 0.31). There was no difference regarding the proportion of VD24 (50.5 versus 55.7%, P = 0.16). Hyperstimulation with non-reassuring cardiotocography (CTG) was more common in the MVI group (14.4 versus 3.0%, P < 0.01). Terbutaline (Bricanyl^® ) was used more often for hyperstimulation in the MVI group (22.7 versus 4.0%, P < 0.01). There was no difference in the numbers of children admitted to the neonatal intensive care unit (NICU).

Conclusions: Vaginal delivery after induction of labour (IOL) with slow-release misoprostol did not result in a shorter time from induction to vaginal delivery, compared with oral misoprostol solution, but was associated with a higher risk for hyperstimulation and fetal distress. There were no differences in mode of delivery or neonatal outcome.

Tweetable abstract: IOL with MVI was similar to oral solution of misoprostol but hyperstimulation and fetal distress were more common.

Keywords: Caesarean section; VD24; induction of labour; oral solution of misoprostol; slow-release vaginal insert of misoprostol.