(1125) Is the etiology of fetal death associated with adverse health outcomes during second-trimester medication abortion?

Objective: Induction of fetal asystole (IFA) is commonly used before second-trimester medication abortion (MAB). Data suggest a higher risk for adverse health outcomes when compared to MAB without IFA. Yet there is a poor understanding of whether the etiology of fetal death (IFA or intrauterine fetal demise [IUFD]) is associated with adverse health outcomes.

Study Design: We analyzed a retrospective cohort of people undergoing second-trimester MAB of a singleton at 4 centers from 2009-2019. Eligible individuals underwent IFA or had IUFD and did not have rupture of membranes, preterm labor, or cervical insufficiency. The primary exposure was etiology of fetal death. Fetal asystole was induced with potassium chloride. The primary outcome was duration of labor. The secondary outcomes were composite morbidity (i.e. uterine rupture, need for blood transfusion, clinical chorioamnionitis, intensive care unit admission, or need or readmission) and its components. Bivariate and multivariate analyses were performed. For the primary outcome, a survival curve was generated, censoring at the time of delivery, and a hazard ratio (HR) was computed. A sensitivity analysis was performed, matching participants based on gestational age and history of uterine scarring.

Results: 399 participants were analyzed. 83 (20.8%) underwent IFA and 316 (79.2%) had IUFD (Table). For the primary outcome, IFA was associated with a longer duration of labor, which was nonsignificant after adjusting for race/ethnicity and receipt of mifepristone (Figure). For the secondary outcomes, there was no difference in composite morbidity between the groups. However, IFA was associated with a higher frequency of uterine rupture and need for blood transfusion on bivariate analyses (Table). On sensitivity analysis, there was only a significant difference in frequency of blood transfusion.

Conclusion: The etiology of fetal death is not consistently associated with an increased length of labor or increased risk of most adverse health outcomes. IFA may be associated with the need for blood transfusion when compared to IUFD, which requires further investigation.