Abstract
Objectives: To assess efficacy and adverse outcomes of misoprostol 200mcg versus 400mcg every three hours buccal or vaginal for medication abortion (MAb) from 24-27 weeks' gestation.
Study design: This retrospective cohort study included MAbs from 24 0/7-27 0/7 weeks' gestation at Bellevue Hospital from 7/2022-6/2025. All patients received digoxin 2mg intraamniotic injection and mifepristone 200mg oral followed at 24-48hrs by misoprostol 200mcg or 400mcg every three hours buccal or vaginal based on hospital policy at time of admission. The primary outcome was time from first misoprostol dose to placental expulsion. Secondary outcomes were procedural complications. Primary statistical analysis was performed with Fisher's exact and Wilcox rank-sum tests.
Results: Of 55 patients, 27 (49%) received 200mcg doses of misoprostol and 28 (51%) received 400mcg doses of misoprostol. Median time to expulsion was 13hrs in the 200mcg group versus 9.5hrs in the 400mcg group (p=0.144). More patients in the 200mcg group versus the 400mcg group had blood loss ≥500mL (11.1% vs 0%, p=0.11) and retained placenta at four hours (3.7% vs 0%, p=0.49). No patients in either group had uterine rupture.
Conclusions: Misoprostol 200mcg versus 400mcg every three hours buccal or vaginal for MAb from 24-27 weeks' gestation had overall similar outcomes. Although this single site retrospective study is underpowered to significantly differentiate between the two regimens, we observe that 200mcg dosing may be associated with higher risk of complications. Larger studies are needed to clarify optimal misoprostol dosing for 24-27 week MAb.
Implications: For medication abortion from 24-27 weeks' gestation, serial doses of misoprostol 200mcg versus 400mcg every three hours have similar rates of complications, though there is a signal that 200mcg dosing may be associated with longer time to expulsion, higher blood loss, and more incidences of retained placenta.