A comparison of PGE2 and PGF2 alpha vaginal gel for ripening the cervix before induction of labour.

The efficacy of a vaginal gel containing either 5 mg prostaglandin E2 (PGE2) or 25 mg prostaglandin F2 alpha (PGF2 alpha) to ripen the unfavourable cervix for labour induction was assessed in a double blind trial. PGF2 alpha, compared with PGE2, had little effect upon the clinical state of the cervix, but the resultant duration of labour in each of the two groups was shorter than in a control group. While the numbers of patients requiring oxytocin stimulation of labour and regional analgesia were reduced in both groups compared with the controls, PGF2 alpha was much less effective than PGE2. Uterine hypertonus was observed using both prostaglandins during an experimental study and the implications are discussed.