Patients undergoing a second trimester surgical abortion procedure require cervical preparation prior to surgery to allow for a safer, more efficient procedure. Patient preference for medications in place of osmotic dilators as cervical preparation is well known. Optimization of the timing interval for medication use prior to second trimester procedures would follow patient preference, could allow for same-day preparation and procedure and eliminate the need for osmotic dilator placement.
This study evaluated women desiring abortion between gestational ages 14 weeks 0 days and 19 weeks 6 days. 100 women received either 200-mg mifepristone or identical placebo with 400-mcg misoprostol vaginally 4-6 hours prior to a second trimester surgical abortion. The largest Hegar dilator accepted without resistance assessed cervical dilation. Total procedure time and patient and provider perceptions were also evaluated.
Of 100 women enrolled, 96 were randomized and completed the study. Age, race, gestational age (mean 17.4 weeks, SD 1.3), parity, and anesthesia did not significantly differ. Mean initial Hegar dilation was 11.7 and 10.9 mm in the mifepristone and placebo groups, respectively, with difference of 0.8 (95%CI -0.4, 2.0). Total procedure times were 11.8 and 13.0 minutes in the mifepristone and placebo groups, respectively, with difference of 1.2 minutes (95%CI -2.4, 4.8). Each additional 1 mm of dilation was associated with a procedure time reduction of 0.6 minutes (p<0.05). Patient and provider perceptions did not differ. All 96 procedures were completed without hemorrhage, cervical laceration, or other observed complications. Vaginal misoprostol is safe and effective as cervical preparation 4-6 hours prior to dilation and evacuation at 14 weeks through 19 weeks 6 days, with or without concurrent oral mifepristone. Greater initial dilation is associated with shorter procedure times.