Association between gestational age and induction-to-abortion interval in mid-trimester pregnancy termination using misoprostol

Objective: The study was aimed to evaluate the effectiveness, outcome, and pain intensity of the vaginal administration of misoprostol for the induction of abortion between 13 and 24 gestational weeks. Study design: A retrospective study was conducted at our tertiary medical center from January 2006 to December 2009 on 122 consecutive women who underwent termination of pregnancy (TOP) in the mid-trimester. They were given 400 mcg of vaginal misoprostol every 6 h, up to four doses. The induction-to-abortion interval and the level of pain experienced during the process were assessed. Success was defined by the fetus being expelled within 48 h. Results: Vaginal misoprostol was effective in 84% (98/122) of patients. The median duration of the induction-to-abortion interval was 16 (5-48) h. The induction-to-abortion interval was correlated with gestational age, while inversely correlated with parity. A correlation was also found between gestational age and pain intensity at 12 h from induction. Conclusion: Misoprostol is safe and effective in mid-trimester abortion induction. The induction-to-abortion interval is shorter and abortion less painful with lower gestational age. Higher parity is also associated with shorter induction to abortion interval.