Vaginal acidity enhancement with a 3% acetic acid gel prior to misoprostol treatment for pregnancy termination in the midtrimester

Abstract

Objective: To investigate whether enhancing vaginal acidity improves the success of medical abortions in the midtrimester.

Methods: A double-blind, randomized, placebo-controlled trial was conducted with 48 women with missed midtrimester abortions. Twice daily, the study participants (n=24) were treated with a 3% acetic acid gel and the controls (n=24) with a placebo gel, starting 2 days prior to initiating the misoprostol treatment. The primary outcome measures were the rates of successful abortion within 24 and 48 hours. Secondary measures included gel tolerability and adverse effects of the misoprostol treatment.

Results: The success rates were higher in the study group, within both 24 hours (11/23 vs 3/24; P=0.011) and 48 hours (18/23 vs 6/24; P<0.001). Among the women with a vaginal pH of 5 or higher at baseline, acidic gel was also associated with higher success rates within 24 hours (8/13 vs 2/15; P<0.01) and 48 hours (13/13 vs 3/15; P<0,001). The vaginal gels were well tolerated and the misoprostol treatment produced no serious adverse effects.

Conclusion: A 3% acetic acid gel appears to be an effective and safe preparatory adjuvant to vaginal misoprostol treatment for midtrimester medical abortions, especially in women with a vaginal pH of 5 or higher. www.controlledtrials.com: ISRCTN75746444.