The efficacy of mifepristone-misoprostol regimen versus misoprostol-only for medication abortion at 22 + 0/7 to 30 + 0/7 weeks’ gestation

Abstract

Objective: This study aimed to compare duration of medication abortion after pretreatment with mifepristone versus misoprostol-only regimens at 22 + 0/7 to 30 + 0/7 weeks. Methods: This retrospective cohort study included patients admitted for medication abortion from 2014 to 2022. Patients underwent feticide due to genetic or anatomical abnormalities at gestational age of 22 + 0/7 to 30 + 0/7 weeks. Excluded from this study were patients admitted at gestational age < 22 + 0/7 or > 30 + 0/7 weeks, with multiple gestation, with diagnosis of intrauterine fetal demise before feticide, with contraindication for vaginal delivery, and who were administered a medical regimen other than the mifepristone-misoprostol or misoprostol-only protocol. Information collected included patients’ demographics, clinical outcomes, additional procedural interventions, and complications. Data of patients treated with mifepristone-misoprostol versus misoprostol-only were compared. Results: The study group included 46 patients in the mifepristone-misoprostol group and 35 in the misoprostol-only group. Median interval from first dose of misoprostol to fetal expulsion was shorter in the mifepristone-misoprostol group (10.6 vs. 15.3 h; p = 0.007) with shorter duration of hospitalization (3.5 ± 1.1 vs. 4.1 ± 1.2 days; p = 0.013). Study groups did not differ in terms of complications. Patients in the mifepristone-misoprostol group had a younger gestational age (23.8 ± 1.69 vs. 25.37 ± 2.4 weeks; p = 0.002). However, multivariable Cox regression found that mifepristone was independently associated with shorter abortion time (OR 1.7, 95% CI 1.03–2.9, p = 0.03). Conclusion: Medication abortion with mifepristone-misoprostol was associated with shorter time to fetal expulsion at gestational ages 22 + 0/7 to 30 + 0/7 weeks, compared with misoprostol-only regimen.