A titrated low-dose misoprostol protocol for second-trimester abortion (13–26 weeks) in women with one prior cesarean and preterm premature rupture of membranes: a clinical practice report

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.