Abstract
Purpose: To compare two starting doses (50 µg vs. 100 µg) of a titrated low-dose misoprostol regimen after mifepristone for second-trimester abortion in women with one prior cesarean and premature rupture of membranes (PROM).
Materials and methods: We retrospectively analyzed 271 eligible women at 13-26 weeks from 6,636 undergoing second-trimester abortion. All received 200 mg mifepristone, followed at 36 h by titrated misoprostol (initial 50 or 100 µg every 3 h, maximum 4 doses per day, escalated to 400 µg based on uterine response). Induction-to-abortion time, total dose, success rates and complications were compared between gestational age groups (13-16 and 16+1-26 weeks) and initial doses using t-tests, chi-square tests, and multivariable regression.
Results: Induction-to-abortion time was similar across groups (15.4-18.6 h). Total misoprostol dose was significantly lower with 50 µg (372-518 µg) than 100 µg (778-878 µg). No uterine rupture or severe hemorrhage occurred. Success rates within 48 h were high (95.7%-97%) and comparable.
Conclusions: The 50 µg starting dose significantly reduced total drug exposure, with similarly high success rates and no observed uterine ruptures. These findings suggest a potentially safe, individualized approach, but require confirmation in prospective randomized trials against standard higher-dose regimens.