Oral and intravaginal prostaglandin E2 for cervical ripening and induction of labour.

The effect of prostaglandin E2 (PGE2) in 'ripening' the cervix was studied in 33 patients who required surgical induction of labour. Patients included primigravidas and parous subjects between 36 and 42 weeks of gestation. Sixteen patients received a total oral dose of 5 mg PGE2 and 17 received 4 - 6 mg PGE2 intravaginally in the form of a gel. There was significant improvement in 'ripeness' of the cervix in all groups, the intravaginal route giving slightly better results than the oral route. Ten patients remained unsuitable for induction because of inadequate dilatation of the cervix or a high fetal head. Four patients on oral therapy developed late decelerations of the fetal heart and 3 of these were delivered by immediate caesarean section. The implications of this and the reasons for the inability to perform inductions after 'ripening' are discussed.