53: Comparison of three regimens using mifepristone and misoprostol for second trimester pregnancy termination

To compare the efficacy of 3 regimens for the administration of misoprostol after mifepristone priming in second trimester pregnancy termination. Prospective randomized trial of pregnancy termination with misoprostol following mifepristone priming at 14-24 weeks gestation. Women received 200mg of mifepristone orally followed 24-48 hours later by 800 mcg misoprostol vaginally. Three regimens for the subsequent misoprostol dosing were compared: 400 mcg oral misoprostol 3-hourly (Group 1), 400 mcg vaginal misoprostol 4-hourly (Group 2), and 400 mcg sublingual misoprostol 3-hourly (Group 3). The primary study outcome was the percentage of women undelivered 12 hours after the administration of the misoprostol loading dose in the 3 groups. 302 women were randomized: 100 to Group 1, 100 to Group 2 and 102 to Group 3. There was no difference in maternal age, race, parity or prior uterine surgery between groups. The median gestation at recruitment was: Group 1 19.1 weeks (interquartile range [IQR] 17.2-20.8), Group 2 19.4 weeks (IQR 17.3-20.4), Group 3 19.7 weeks (IQR 17.6-21.0); p=0.577. The duration from mifepristone administration until misoprostol commencement did not differ: Group 1 37.4 hours (IQR 27.8-42.8), Group 2 31.9 hours (IQR 26.8-41.7), Group 3 29.7 (IQR 26.1-41.6); p=0.177. Duration of termination differed significantly: Group 1 9.5 hours (IQR 6.6-15.4), Group 2 7.8 hours (IQR 5.8-11.5) and Group 3 7.0 hours (IQR 5.8-11.1); p=0.005, with 38% (n=38) of women in Group 1, 23% (n=23) in Group 2 and 22.5% (n=23) in Group 3 undelivered at 12 hours, and 13% (n=13) of women in Group 1, 4% (n=4) in Group 2 and 5.9% (n=6) in Group 3 undelivered at 24 hours. There was no difference in the occurrence of complications between the groups. Vaginal or sublingual misoprostol administered after a vaginal loading dose in second trimester pregnancy termination with mifepristone priming significantly decreases the procedural duration compared with an oral misoprostol regimen.