Higher BMI Linked to Longer Fetal Expulsion Times in Second and Third Trimester Medication Abortions: Study

The findings, published in the journal Contraception, suggest that individuals with a BMI over 30 experience significantly longer times for fetal expulsion compared to those with lower BMI. These insights may prompt adjustments to reproductive healthcare induction protocols and counseling practices.

"Among individuals undergoing medication abortion beyond 13 weeks, those with a BMI ≥30 were 6.62 times more likely to experience a time to expulsion exceeding 24 hours. The median expulsion time for individuals with a BMI ≥30 was 20 hours, compared to 12 hours for those with a BMI <25," the researchers reported.

Megan Fuerst, Oregon Health & Science University, Department of Family Planning, Portland Oregon, and colleagues aimed to investigate the relationship between BMI, kg/m², and the duration of fetal expulsion in individuals undergoing medication-induced abortion beyond 13 weeks of gestation.

For this purpose, the researchers conducted a retrospective cohort study focusing on singleton pregnancies undergoing medication-induced abortion beyond 13 weeks of gestation at a single academic medical center between 2020 and 2024.

The primary outcome measured was the time to fetal expulsion. Participants were grouped into three BMI categories: <25, 25–29.9, and ≥30. The researchers compared the median time to fetal expulsion across these groups and employed multivariable logistic regression models to analyze the association between BMI and prolonged time to delivery, defined as 24 hours or more.

The following were the key findings of the study:

• Four-hundred twenty eight charts were reviewed, and 382 patients met the inclusion criteria, with an average gestational duration of 25.0 weeks.
• Of these, 162 patients (42.4%) had a BMI greater than 30.
• The BMI 25–29.9 group included 120 individuals (31.4%), and the BMI <25 group comprised 100 individuals (26.2%).
• Median time to fetal expulsion varied significantly across BMI categories:
  • 12 hours for BMI <25.
  • 14 hours for BMI 25–29.9.
  • 20 hours for BMI ≥30.
• After adjusting for gestational duration, cesarean section history, and prior vaginal deliveries, individuals with a BMI ≥30 had 6.62 times the odds of experiencing a time to expulsion ≥24 hours compared to those with a BMI <25.

"Our findings indicate that individuals with a BMI >30 experience significantly longer times to fetal expulsion during the second and third trimesters. This suggests a need to tailor induction protocols and counseling practices to account for body size," the researchers concluded.

Reference:

Fuerst, M., Prewitt, K. C., Garg, B., Ramanadhan, S., & Han, L. (2024). Association of Body Mass Index on time to fetal expulsion for individuals undergoing medication abortion over 13 weeks gestational duration. Contraception, 110752. https://doi.org/10.1016/j.contraception.2024.110752