Induction of labour in nulliparas with poor cervical score: oxytocin or prostaglandin vaginal pessaries?

In a previous study nulliparas with poor cervical score (less than 5 out of 10) had a 43.5% Caesarean section (CS) rate of which 55% were for failed induction when labour was induced by artificial rupture of membranes and oxytocin infusion. In this study induction of labour by 2 doses of 3 mg prostaglandin E2 (PGE2) vaginal pessaries, 4 hours apart, and if necessary by artificial rupture of membranes and oxytocin infusion 24 hours later, resulted in a CS rate of 23.7% of which 38.9% were for failed induction. The latter regimen resulted in a significantly lower CS rate compared with labour induced by oxytocin infusion and rupture of membranes without the use of prostaglandins (p less than 0.001). In the prostaglandin group 53.3% were established in labour within 24 hours of inserting the pessary and in these patients the CS rate was 18.5%. In those who did not start labour and needed rupture of membranes and oxytocin infusion 24 hours after the first pessary, 34 (47.9%) had a good cervical score (greater than or equal to 6 out of 10) and 37 (52.1%) had a poor cervical score (less than or equal to 5 out of 10) at the time of amniotomy. The CS rates in these groups were 8.8% and 48.6% respectively (p less than 0.001). In nulliparas with poor cervical score induction is better performed with vaginal prostaglandin pessaries in order to reduce the high CS rate associated with artificial rupture of membranes and oxytocin infusion.