Maternal complications associated with second trimester medical abortion using mifepristone priming and subsequent misoprostol

OBJECTIVE: To assess the frequency of maternal adverse events associated with second trimester medical abortion using sequential mifepristone and misoprostol.

STUDY DESIGN: Retrospective analysis of medical abortions 13-28 weeks gestation using sequential mifepristone and misoprostol in a single center from 1/2008-12/2018. The main outcomes evaluated were the nature and incidence of adverse procedural events and the impact of gestation upon these outcomes.

RESULTS: During the study period, 1393 people underwent a medical abortion with sequential mifepristone and misoprostol. The median maternal age was 31 years (IQR 27-36 years) and 21.8% had at least one prior cesarean delivery. The median gestational age at abortion commencement was 19 weeks (IQR 17,21). The main adverse maternal events were complete or partial placental retention greater than 60 minutes triggering removal in the operating room (19%), maternal hemorrhage >1000 cc (4.3%), blood transfusion (1.7%), hospital readmission (1.4%), uterine rupture (0.29%) and hysterectomy (0.07%). There were significant reductions in placental retention rates with increasing gestational age (23.3% at 13-16 weeks gestation declining to 10.1% at >23 weeks gestation, p < 0.001).

CONCLUSION: Serious adverse maternal events associated with second trimester medical abortion with sequential mifepristone-misoprostol are uncommon.

IMPLICATIONS: Second trimester medical abortion with mifepristone and misoprostol is generally safe, however on occasions serious complications may occur. All health care units providing a medical abortion service require the facilities and expertise to deal with these adverse events in a timely manner.