Comparison of vaginal and buccal misoprostol after mifepristone for medication abortion through 70 days of gestation: A retrospective chart review

Abstract

Objective: To determine the proportion of complete abortion without surgical intervention for patients who chose medication abortion with vaginal compared to buccal misoprostol following oral mifepristone through 70 days of gestation.

Methods: We performed a retrospective cohort study. We reviewed charts via electronic medical record data abstraction of patients receiving medication abortion with mifepristone and buccal or vaginal misoprostol between September 1, 2017 and August 1, 2019. Primary outcome was complete abortion without surgical intervention for any indication. Secondary outcomes were ongoing pregnancy and uterine aspiration for indications other than ongoing pregnancy.

Results: There were 14,504 encounters included in the data set. Of the 4814 patients who took vaginal misoprostol and the 4011 patients who took buccal misoprostol for whom follow up data is available, 4640 (96.4%) and 3917 (97.7%) had a complete abortion without surgical intervention, respectively (p = 0.002). At <64 days of gestation, complete abortion was 96.6% for vaginal administration compared to 98.0% for buccal (p = 0.001). At 64 to 70 days of gestation, complete abortion was 92.7% for vaginal administration compared to 93.2% for buccal (p = 0.08). Of the 1128 patients who took vaginal misoprostol at less than 6 hours after mifepristone, 95.3% experienced a complete abortion.

Conclusion: Buccal administration of misoprostol is associated with a higher proportion of complete abortion before 64 days of gestation compared to vaginal misoprostol. Clinically, vaginal misoprostol is an effective route of administration through 70 days of gestation.

Implications: Medication abortion with vaginal misoprostol is effective when administered through 70 days of gestation and with shorter intervals between mifepristone and misoprostol. Prospective research to better estimate effectiveness is warranted. Expanding medication abortion options promotes patient autonomy amid increasing restrictions and bans on abortion.

Keywords: Continuing pregnancy; Medication abortion; Mifepristone; Vaginal misoprostol.