Background: Misoprostol, a cheap, stable, orally active prostaglandin analogue, is effective for labour induction when administered either vaginally or orally, but uterine hyperstimulation and rupture have been reported. Previous studies of oral misoprostol for labour induction have used fixed dosages 3-6-hourly.
Objectives: To develop a new method of misoprostol use for labour induction using very small, frequent, titrated oral dosages, and to pilot effectiveness.
Study design: Open clinical pilot study.
Setting: Coronation Hospital, an academic hospital in Johannesburg, South Africa.
Methods: We developed a method using 2-hourly titrated misoprostol doses commencing with 20 micrograms, increased after three doses to 40 micrograms. To administer such small doses we dissolved one misoprostol tablet in 200 ml water. A pilot study of this method was undertaken in 25 women with various indications for induction of labour.
Results: Eighteen women (72%) delivered vaginally within 32 hours of induction and two women developed uterine hyperstimulation. The caesarean section rate was 20%.
Conclusions: Women may respond to much smaller dosages of misoprostol than are currently in use. A multicentre randomised trial of this method is underway. We emphasise the dangers inherent in the current unregistered use of misoprostol in clinical practice.