COMPLICATIONS ASSOCIATED WITH MIFEPRISTONE USE FOR DILATION AND EVACUATION ABORTION PROCEDURES BETWEEN 22 AND 24 WEEKS’ GESTATION

Objectives

Dilation and evacuation is the most common method of procedural abortion after 20 weeks’ gestation. Adequate cervical dilation is essential for safe dilation and evacuation. In 2017, the British Pregnancy Advisory Service (BPAS) added mifepristone to their regimen of osmotic dilators for cervical ripening before dilation and evacuation. This retrospective study analyzed the risk for complications associated with the use of mifepristone for cervical ripening.

Methods

BPAS provided data which included dilation and evacuation procedures that occurred between 22 weeks’ and 23 weeks and 6 days’ gestation, between February 2012 and February 2017 (osmotic dilators only), and November 2017 to November 2022 (mifepristone and osmotic dilators). Using time as a proxy for mifepristone use, the association between mifepristone use and dilation and evacuation complications was established. Multivariate logistic regression was used to calculate the odds for complications with and without mifepristone use while controlling for potential confounders.

Results

There were 6,516 dilation and evacuation procedures at BPAS during this time. Those who received mifepristone were more likely to experience any complication (OR: 2.40, 95% CI: 1.62, 3.54). They also had higher odds of bleeding (OR: 3.08, 95% CI: 1.12, 8.48). Odds for cervical injury (OR: 2.21, 95% CI: 0.84, 5.80) and infection (OR: 1.89, 95% CI: 0.46, 7.69) were not different between those who did and did not receive mifepristone.

Conclusions

The addition of mifepristone to osmotic dilators was associated with an increase in the odds of complications of dilation and evacuation, without attenuating the risk of complications related to cervical dilation.