BACKGROUND: Pre-induction of labor cervical ripening increases success of labor induction when there is unfavorable cervix. Evening primrose oil soft gel capsule contains linoleic and gamma-linolenic acid, which are precursors of prostaglandins E1 andE2.
OBJECTIVE: To measure the effectiveness of evening primrose oil capsule as a cervical ripening agent by measuring the Bishop score before and 4 hours after intravaginal insertion of six capsules.
METHODS: A quasi-experimental cross-sectional study was conducted from the period of May to July 2016 involving labor induction patients with a Bishop score ?4, an intact amniotic sac and a Biophysical profile score of 10/10 or 8/8.
RESULTS: Thirteen patients had an average age of 27±6 years, and a mean age of gestation of 40±1 weeks. Seven patients (54%) were nulliparous, 2 (15%) were primiparous and 4 (31%) were multiparous. Seven patients (54%) had hypertension, 1 (8%) had diabetes mellitus, 5 (38%) had post-term pregnancies. A paired t-test was done to check for statistically significant changes in the Bishop score. Change in the Bishop score from baseline to 4 hours after insertion of evening primrose oil capsules was statistically significant (p=0.001). Eleven patients (85%) had improvement in the Bishop score after 4 hours, 4 (31%) of which had a clinically significant change in the Bishop score (?4). Specifically, there were statistically significant changes in the dilatation (p=0.027), effacement (p=0.006) and consistency (p=0.002). The mean birth weight of deliveries was 3192±351 grams. Nine patients (69%) underwent primary low segment cesarean section, six (46%) of which for nonreassuring fetal status, 2 (15%) for arrest in cervical dilatation, and 1 (8%) for intraamnionic infection. Four patients (31%) successfully delivered vaginally.
CONCLUSION: Results showed a positive effect on the Bishop score during cervical ripening although further studies are needed to establish direct correlation.