Castor oil for labor initiation in women with a previous cesarean section: a double-blind randomized study.

To evaluate the efficacy of castor oil in initiation of labor in women who had one previous cesarean section. This study was conducted as a trial to increase the rate of vaginal birth after cesarean (VBAC) and decrease the rate of elective repeated cesarean section (ERCS). A double-blinded randomized controlled study was conducted in an Egyptian University Hospital from July 2019 to July 2020. The participants were 70 pregnant women who had one previous cesarean section, singleton pregnancy in cephalic presentation, with a Bishop score ≤6 attempting to perform a trial of labor. Sixty mL castor oil was administered to group A and 60 mL sunflower oil was administered to group B (as a placebo) for initiation of labor at the start of week 39. Primary outcomes were the percentage of women entering the active phase of labor within 24 h after receiving castor oil or placebo and the number of successful VBAC deliveries. Labor started in 16 patients (45.7%) within 24 h in the castor oil group and in 3 patients in the placebo group (8.5%), while the rate of successful VBAC was 65.7% (23 patients) in the castor oil group and 48.5% (17 patients) in the placebo group. Castor oil appears to be an effective, low-cost, and non-harmful method for the initiation of labor in patients with a previous cesarean section.