Induction of labour in nulliparous women with an unfavourable cervix: a randomised controlled trial comparing double and single balloon catheters and PGE2 gel.

OBJECTIVE: To compare the efficacy and patient satisfaction of three methods of labour induction (double balloon catheters, single balloon catheters and prostaglandin gel) in term nulliparous women with unfavourable cervices.

DESIGN: Randomised controlled trial.

POPULATION: A total of 330 nulliparous women with unfavourable cervices induced at term.

METHODS: Three cervical ripening study arms were used: double balloon catheter (107 women); 16F Foley catheter (110 women) and PGE(2) gel (2 mg) (113 women).

MAIN OUTCOME MEASURES: Caesarean section, induction to delivery interval, adverse reactions and patient satisfaction.

RESULTS: There was no difference in caesarean delivery rates between groups (double balloon 43%, single balloon 36%, PGE(2) 37%, P = 0.567). The induction to delivery interval was longer in the double balloon group (median 24.5; 95% CI 23.7, 30.6 hours) than the single balloon (23.2; 20.8, 25.8 hours) or PGE(2) (23.8; 21.7, 26.8 hours) (P = 0.043). Uterine hyperstimulation occurred in 14% of the PGE(2) group with none occurring with mechanical cervical ripening. Cord blood gases were worse in the PGE(2) group: median arterial pH double balloon 7.26 (range 7.03-7.40); single balloon 7.26 (7.05-7.44); PGE(2) 7.25 (6.91-7.41) (P = 0.050). Cervical ripening with the single balloon catheter was associated with significantly less pain (pain score > or =4: double balloon 55%, single balloon 36%, PGE(2) 63%, P < 0.001).

CONCLUSIONS: Labour induction in nullipara with unfavourable cervices results in high caesarean delivery rates. Although all methods in this study had similar efficacy, the single balloon catheter offers the best combination of safety and patient comfort.