Misoprostol in Abortion Care: Review and Update

We seek to update readers on misoprostol use in abortion care. We discuss literature on misoprostol use in first trimester medication abortion, second trimester induction abortion, management of early pregnancy loss, and first and second trimester surgical abortion. We review publications investigating efficacy, acceptability, and safety of misoprostol doses, routes of administration, use with mifepristone and osmotic dilators, and timing in relation to mifepristone or surgery.

In 2016, the Food and Drug Administration approved updated labeling for medication abortion: mifepristone 200 mg oral followed in 24–48 h by misoprostol 800 mcg buccal through 70 days gestation. Intervals less than 24 h decrease efficacy. The addition of mifepristone to misoprostol for second trimester induction abortion decreases time from misoprostol to complete uterine evacuation. Misoprostol may be used alone or in combination with osmotic dilators or mifepristone for cervical preparation for surgical abortion. Routine cervical priming with misoprostol is not recommended in the first trimester. Same-day cervical preparation with misoprostol may be used from the late first trimester through 18–20 weeks, although additional mechanical dilation may be required. After 18–20 weeks, misoprostol may be used with overnight osmotic dilators, although mifepristone may be preferred to avoid misoprostol side effects and enhance ease of the surgical procedure.

Misoprostol plays an indispensable role in abortion care and may be administered in doses of 400–800 mcg by oral, buccal, vaginal, and sublingual routes. More studies are needed to assess variations in dose and timing and to determine upper gestational age limits for same-day preparation.