Effect of misoprostol with and without evening primrose (Oenothera biennis) on induction of missed abortion.

Objective: To determine whether addition of evening primrose to a misoprostol-based abortion regimen can increase the success of abortion.

Materials and methods: In this randomized clinical trial., 148 women referring to Niknafas Hospital in Rafsanajn with diagnosis of missed abortion were randomly allocated into two 74-subject groups. The intervention group used 2000 mg vaginal evening primrose capsules the night before the hospitalization, while the control group did not receive any medication. Both groups received an initial dose of 800 μg of vaginal misoprostol after admission and the next dose was given three hours later if necessary.

Results: The two groups had significant differences in terms of full abortion, consistency and dilatation of cervix, duration between the first dose of misoprostol until the ejection of fetus, the misoprostol dose administered, and the level of vaginal bleeding during the hospitalization. They had no significant differences regarding curettage, duration of hospitalization, or side effects. The mean pain score had no significant difference between the two groups, though the score was lower in the intervention group (p>0.05).

Conclusion: Administration of vaginal evening primrose before vaginal misoprostol was found to be more effective compared to misoprostol alone in missed abortion.