Randomized trial of administration of prostaglandin E₂ gel for induction of labor in the morning or the evening

Objective: To compare the outcome of induction of labor and patient's preferences using a protocol with the first dose of prostaglandin E₂ endocervical gel in the evening versus a protocol with the first dose in the morning. Design: We performed a randomized trial comparing administration of prostaglandin E₂ endocervical gel in the morning with administration of prostaglandin E₂ gel in the evening, followed if necessary by a second dose being given after six hours if labor had not started or the cervix was still unripe. Formal induction of labor by amniotomy and oxytocin infusion was performed the morning after the initial prostaglandin E₂ dose. Patients' preferences were assessed using a questionnaire that was completed after delivery. Setting: Tertiary care hospital in the Netherlands with 1600 deliveries per year. PARTICIPANTS: One-hundred and twenty-six women with viable singleton pregnancies at term who had induction of labor with prostaglandins. Main outcome measures: Time of delivery (daytime, evening or night) and patient's satisfaction. Results: Fifty-eight women were allocated for administration of gel in the morning, whereas 68 had their gel in the evening. Administration of gel in the evening did not significantly reduce delivery between 23.00 hours and 08.00 hours, although there was a reduction in delivery between 23.00 hours and 08.00 hours in nulliparae. None of the multiparous women delivered between 18.00 hours and 23.00 hours after induction of labor in the evening. The relative risk for delivery by vacuum or forceps was increased after allocation of gel in the evening (4.2; 95% confidence limits 1.4 to 13). Patients' preferences favored administration of gel in the morning. Conclusions: There was no benefit in starting induction of labor with prostaglandin E₂ in the evening, compared with starting in the morning.