A study on the Safety and Efficacy of Castor Oil for Cervical Ripening and Labour Induction

Castor oil was first noted to have oxytocic properties by ancient Egyptians. Derived from the castor plant Ricinus communis, castor oil may possess properties that are useful in post term pregnancies. The purpose of this study was to determine the safety and efficacy of castor oil for cervical ripening and labour induction.Subjects and This study was performed at Khatam-Al-Anbia hospital, Shoushtar, in 1381. In this clinical trial 80 pregnant women, were randomly assigned to the study group (n = 40), to whom a single 60 ml, diluted in orange juice, oral dose of castor oil, or assigned to a placebo group (n = 40). Inclusion criteria were post-term pregnancy, singleton with vertex presentation, Intact membranes, Bishop score of 4 or less, no evidence of regular uterine contractions and gravity 1 – 2. Exclusion criteria were placenta previa, previous caesarean section or hysterectomy and maternal medical complications. After the initial 12 hours of castor oil administration a repeated Bishop score assessment was made by the same initial examiner. All patients were observed for labour onset for 12 hours after castor oil administration. If labour did not occur during this time, the patients were placed on a standardized oxytocin induction regimen. Both groups of women did not differ in maternal age, parity, initial Bishop score or gestation age. Following the administration of castor oil, 25 out of 40 woman (62.5 %) on caster oil regimen began active labour, compared to 3 of the 40 woman (7.5%) receiving placebo (p< 0. 001). The mean change in the Bishop score was significantly higher in those receiving castor oil (2 vs. 0.5, p < 0.001). Fewer patients on the castor oil group required oxytocin augmentation (37.5% vs 92.5%, p = 0). There were nearly three times as many caesarean section in the control group (22.5%) compared to the castor oil group (7.5%), but the difference was not significant. The incidence of meconium - stained amniotic fluid, Apgar scores, and birth weights was similar in both groups. All newborn neonates had a 5- minute Apgar score greater than 7. In the castor oil group, there was a case of uterine hypertonicity, but this was not problematic. The expected maternal side effects of castor oil, which includes liquid stools and nausea, did occur in almost patient. Woman who receive castor oil have an increased likelihood of initiation of early labour within 12 hours compared to woman who receive placebo.