Early medical abortion before missed menses: a prospective observational study of outcomes of abortion at less than 30 days from last menstrual period.

Abstract

Introduction: High-sensitivity urine pregnancy tests can detect pregnancy before missed menses. The widespread availability of these tests, alongside improvements in abortion access in many settings, may mean more women present for abortion at a very early stage of pregnancy. We aimed to examine the outcome of early medical abortion (EMA) in pregnancies less than 30 days from last menstrual period (LMP).

Methods: This study analysed prospectively collected data on patients at less than 30 days from LMP seeking abortion at a single service in Edinburgh, UK between March 2020 and December 2023. We determined the effectiveness, outcomes of the pregnancy (complete abortion, ongoing pregnancy, incomplete abortion) and serious complications among those seeking EMA at this gestation.

Results: Of 13 565 patients seeking abortion, 78 (0.6%) presented with a self-reported positive home pregnancy test and less than 30 days from LMP. Some 63/78 patients (81%) proceeded to EMA with mifepristone followed by misoprostol. Of this group, 31/63 (49%) had a pre-abortion ultrasound. Complete abortion occurred in 58/63 (92%, 95% CI 82% to 97%), 4/63 (6%) had an ongoing pregnancy and 1 (1%) had a surgical evacuation for incomplete abortion. There were no serious complications.

Conclusions: Only a very small percentage of patients present for abortion before a missed period. Nevertheless, EMA at this stage is safe and effective. There may be a higher rate of ongoing pregnancy, and so those patients wishing to proceed to EMA should be advised of the importance of confirming success in line with local protocols.