A prospective double blind trial investigating impact of vaginal pH on efficacy of prostaglandin gel for cervical ripening and course of labour.

This prospective, double blind investigation was carried out to see the effect of vaginal pH on the efficacy of prostaglandin gel (PGE2) for cervical ripening and course of labour. A total of 45 pregnant women with indications for induction of labour were allocated to two groups: a low vaginal pH (≤5.5, n = 20) and high vaginal pH (>5.5, n = 25) group. All women received prostaglandin E2 gel (0.5 mg in 2.5 ml) intravaginally with repeated dosing if needed, 6 h apart, maximum of three doses. Bishop's score change over 18 h differed significantly between the two groups (p = 0.037). There was no significant difference between the groups with respect to time to onset of labour (9.65±6.29 vs 6.76±3.94, p = 0.066), time to active labour (15.38±9.49 vs 14.30±5.85, p = 0.664), time to complete cervical dilation (18.27±13.85 vs 18.34±6.45; p = 0.984), and time to overall delivery (21.52±9.66 vs 19.39±6.45, p = 0.381).