A pilot study to compare propranolol and misoprostol versus misoprostol and placebo for induction of labor in primigravidae; a randomized, single-blinded, placebo-controlled trial

BACKGROUND: The Induction of labor is the most common obstetric procedure in daily practice. Introducing propranolol as a new drug to augment the action of prostaglandins will help in the induction process and decrease CS rates. Several researchers have used propranolol in the augmentation of labor. AIM: This pilot study compares propranolol and misoprostol versus misoprostol alone for labor induction in primigravids. METHODS: This is a Randomized clinical trial, single-blinded, placebo-controlled trial at Ain Shams University Maternity hospital. This study included 128 pregnant full-term primigravid women candidates for labor induction, randomized into two groups. All candidates underwent labor induction with 25 µg of vaginal misoprostol. Group I received 20 mg of oral propranolol tablets, while group II received sugary pills as a placebo. Candidates who responded successfully to induction were assessed for possible augmentation of labor by amniotomy or oxytocin infusion. The Primary outcome was induction to delivery interval, while the secondary outcomes were the duration of the latent phase, mode of delivery, and APGAR score of the neonate. RESULTS: The induction-delivery time was (11.8 ± 8.1 h. vs. 12.6 ± 8.9 h., P value = 0.027) and the duration of the latent phase of labor (7.9 ± 5.6 h. vs. 9.2 ± 6.03 h., P value = 0.017) were significantly shorter in the group of misoprostol and propranolol compared to the group of misoprostol and placebo. There was no statistically significant difference between both groups’ mode of delivery, indications for cesarean section, misoprostol, and oxytocin doses, or neonatal outcome. (P value > 0.05). CONCLUSION: Propranolol, when used with misoprostol for induction of labor, results in augmentation of action of misoprostol and a significantly shorter induction-delivery interval. TRIAL REGISTRATION: We retrospectively registered this trial in clinicaltrial.gov on 01/09/2020 (NCT04533841). https://clinicaltrials.gov/ct2/show/NCT04533841