The Use of Castor Oil as a Labor Initiator in Post-date Pregnancies

Castor oil is traditionally given by midwives in order to induce labor. Its efficacy as an initiator of labor was previously tested only in one clinical trial. Unfortunately this study (by Garry et al.) was not sufficiently controlled. We intent to recruit 84 healthy pregnant women with no contraindication to vaginal delivery that had past their due date. Women will be randomly and blindly divided into equal sized intervention group and control group. Intervention group will be given 60 mL of castor oil in 140 mL of orange juice, while control group will be given a placebo with similar texture. Primary outcome to be tested is the percentage of women entering active labor within 24 hours of administration.

Inclusion Criteria: Pregnant women at 40-42 weeks gestation Good obstetrical dating Singleton Intact membranes Preinterventional Bishop score less than or equals 4 No evidence of effective uterine contractions by external tocography Living close to hospital Exclusion Criteria: Multiple gestation Oligohydramnios or Polyhydramnios Abnormal FHR tracing Obstetric complication (hypertension, bleeding) Ruptured membranes Suspected intrauterine growth restriction Biophysical score < 8 Previous cesarean section / myomectomy / Other uterine operation Fever, malaise at recruitment Chronic illness (renal, hepatic, endocrine)

Garry D, Figueroa R, Guillaume J, Cucco V. Use of castor oil in pregnancies at term. Altern Ther Health Med. 2000 Jan;6(1):77-9.