Medication abortion for pregnancy of unknown location a reasonable option

Reference

Goldberg AB, Fulcher IR, Fortin J, et al. Mifepristone and misoprostol for undesired pregnancy of unknown location. Obstet Gynecol 2022:139(5):771-180.

Synopsis

This study is a retrospective cohort of 452 patients with a positive pregnancy test result seeking medication abortion within 42 days of last menstrual period (LMP). The patients also had an initial ultrasound showing no gestational sac (intrauterine or ectopic). Those with major risk factors for ectopic pregnancy (intrauterine device in situ, prior tubal surgery, prior ectopic pregnancy) were not eligible for same-day treatment and were excluded from the study. Of this cohort, 55 (12%) received same-day start of medication abortion at the discretion of the treating provider using mifepristone (200 mg orally) followed by misoprostol (800 mcg self-administered orally within 48 hours), and serial quantitative human chorionic gonadotropin (hCG) testing. The remaining patients were not treated until intrauterine or ectopic pregnancy was determined (delay-for-diagnosis group). Initial hCG results were received after medication administration. If the hCG level was less than 2000, medication abortion could proceed as planned. An hCG level from 2000 to 2999 required repeat ultrasound on the same day as results were received. If the hCG level was 3000 or greater, the patient was referred to the emergency department for further evaluation to exclude ectopic pregnancy. The incidence of ectopic pregnancy was 31/452 (6.9%; 95% CI 4.7 - 9.6), of which 25 presented with symptoms of ectopic pregnancy at initial evaluation, all of which were in the delay-for-diagnosis group. Of the rest of the delay-for-diagnosis group, 161 (40.9%) eventually proceeded with medication abortion regimen and 62 (15.7%) switched to uterine aspiration. The primary outcome of median time to diagnosis of pregnancy location was 5 days in the same-day-treatment group and 9 days in the delay-for-diagnosis group (P = .005). In the delay-for-diagnosis group, there were 9 (2.4%) patients with adverse events (ruptured ectopic pregnancy, hemorrhage > 500 mL, blood transfusion, hospital admission) and none in the same-day treatment group. The analysis of medication abortion efficacy included only the 170 patients who received it and had known pregnancy outcomes. Successful abortion, defined as a serum hCG decrease by at least 50% 48 to 72 hours after mifepristone or by 80% by 1 week after misoprostol, was lower in the same-day treatment group (85% vs 97%; P = .013). Nonadherence to follow-up did not differ between groups.