Association of body mass index on time to fetal expulsion for individuals undergoing medication abortion over 13...

This study aimed to examine the association of body mass index (BMI, kg/m²) with time to fetal expulsion for individuals undergoing medication abortion over 13 weeks.

This is a retrospective cohort study of singleton pregnancies undergoing medication abortion >13 weeks at a single academic medical center between 2020 and 2024. Our primary outcome was time to fetal expulsion. We categorized BMI into three groups (>25, 25-29.9, and ≥30) and compared median time to fetal expulsion. We used multivariable logistic regression models to assess the association of BMI with time to delivery ≥24hours.

Of the 428 charts reviewed, 382 patients met the inclusion criteria with an average gestational duration of 25.0 weeks. Of these, 162 (42.4%) had a BMI >30 kg/m²; 120 individuals fell into the BMI 25 to 29.9 group (31.4%), and the remaining 100 individuals made up the BMI <25 group (26.2%). The median time to expulsion differed significantly among BMI categories (12 hours for BMI <25 [IQR 8-18], 14 hours for BMI 25-29.9 [IQR 8-22], 20 hours for BMI ≥30 [IQR 12-28], p < 0.001). After adjusting for gestational duration, history of cesarean section, or prior vaginal deliveries, individuals with a BMI ≥30 had 6.62 times the odds (95% CI 3.27-13.44) of having a time to expulsion ≥24 hours compared to BMI <25.

Individuals with a BMI >30 had significantly longer second and third trimester time to fetal expulsion. Induction protocols and counseling may need to be adjusted based on body size.

Individuals with a BMI >30 undergoing a medication abortion >13 weeks have longer time to fetal expulsion than those with a BMI <25. More research is needed to optimize induction protocols and abortion care for high BMI individuals.