For a study, researchers sought to assess the effects of immediate vs delayed medication abortion in patients who had an unwanted pregnancy with an uncertain location. Patients who requested medication abortion with a last menstrual period (LMP) of 42 days or less and pregnancy of unknown location (no gestational sac) on initial ultrasonogram were included in the retrospective cohort study, which used electronic medical records from the Planned Parenthood League of Massachusetts (2014–2019). Clinicians could use mifepristone followed by misoprostol to induce medication abortion while also excluding ectopic pregnancy with serial serum human chorionic gonadotropin (hCG) testing (same-day-start group) or establish a diagnosis with serial hCG tests and a repeat ultrasonogram before starting treatment (delay-for-diagnosis group). They evaluated primary safety outcomes across groups (time to diagnosis of pregnancy site [rule out ectopic], emergency department visits, adverse events, and nonadherence with follow-up). Secondary efficacy outcomes were time to complete abortion, effective medication abortion (no uterine aspiration), and continued pregnancy.

About 452 patients had an unknown location pregnancy out of 5,619 medication abortion visits for patients having an LMP of 42 days or less (8.0%). Just 3 patients experienced immediate uterine aspiration, 55 had a same-day start, and 394 had a diagnostic delay. Around 31 patients (7.9%), all from the delay-for-diagnosis group, were treated for ectopic pregnancy, four of whom ruptured. The same-day start had a shorter time to diagnosis (median 5.0 days vs 9.0 days; P=.005), with no significant difference in emergency department visits (aOR 0.90, 95% CI 0.43–1.88) or nonadherence with follow-up (aOR 0.92, 95% CI 0.39–2.15) among patients with no major ectopic pregnancy risk factors (n=432). Same-day abortion (median 5.0 days vs 19.0 days; P<.001) took less time to accomplish among patients who proceeded with abortion (n=270). The incidence of effective medication abortion was lower (85.4% vs 96.7%; P=.013) and the rate of continued pregnancy was greater (10.4% vs 2.5%; P=.041) among patients who had medication abortion with known results (n=170). In patients with an unwanted pregnancy of uncertain site, prompt commencement of pharmaceutical abortion was related to faster ectopic pregnancy exclusion and pregnancy termination but worse abortion effectiveness.