Extra-amniotic misoprostol as a cervical ripening agent - abstract

ABSTRACT

There are many indications for induction of labour. When the cervix is ripe, induction of labour with oxytocin is easy. When the cervix is unripe, induction can fail, leading to prolonged labour and an increased Caesarean Section rate. Dinoprostone (Prostin, Upjohn) is the drug of choice used to ripen the cervix prior to induction. This drug is, however, very expensive and is sometimes not readily available. We have used a cheaper prostaglandin, misoprostol (Cytotec, Searle) as an extra-amniotic preparation in two studies, to test its efficacy in cervical ripening and achieving a safe vaginal delivery. In a double-blind controlled trial in 23 women with post-dates pregnancy, misoprostol was better than placebo in ripening the cervix (mean change in Bishop score 5.8 vs 1.9, p = 0.002) and fewer patients had no change in the Bishop score (1/12 vs 6/11, p = 0.03). Almost all of the patients given misoprostol went into spontaneous labour (10/12 vs 1/11, p = 0.002) and the mean time from insertion to delivery was shorter (34.1 hours vs 54.0 hours, p = 0.01). In a prospective randomised trial in 26 pre-eclamptic women, misoprostol was better than dinoprostone in ripening the cervix (mean change in Bishop score 5.1 vs 2.8, p = 0.015.). The mean time from insertion to delivery was also shorter (16.4 hours vs 39.3 hours, p = 0.48). In both studies, there were no significant differences between misoprostol and the other drugs in route of delivery. Maternal complications were slightly more than with placebo but of a minor nature. Maternal and foetal outcomes were not significantly different from dinoprostone (AU)