Similar time to delivery with 25 µg, 50 µg misoprostol for women with obesity

Key takeaways:

• Women with obesity who received vaginal misoprostol 25 µg and 50 µg had no difference in time to delivery.
• Multiparous women had significantly reduced time to delivery with vaginal misoprostol 50 µg.

Among women with obesity, 50 µg and 25 µg vaginal misoprostol were associated with similar time to delivery, but multiparous women had significantly reduced time to delivery with 50 µg, according to data presented at The Pregnancy Meeting.

“Clinically, patients with obesity experience an increased duration of labor with significantly increased risks for perinatal morbidity, such as maternal hemorrhage, infection and cesarean delivery,” Alexander M. Saucedo, MD, an obstetrician and gynecologist at Dell Medical School at the University of Texas at Austin, told Healio. “However, there is a paucity of research and professional guidelines detailing effective labor management regimens in this population. It is unclear whether the same dose of misoprostol should be used for induction of labor in obese compared to non-obese patients.”

Saucedo and colleagues conducted a double-blind, pragmatic randomized controlled trial with data from 179 women from June 2022 to July 2023. All women had a BMI of 30 kg/m² or higher and were undergoing labor induction at 36 weeks or more with singleton gestations with a cervical dilation of 3 cm or more on hospital admission. The women were randomly assigned to vaginal misoprostol 25 µg (n = 88) or 50 µg (n = 91) every 4 hours until delivery. In total, 106 women were nulliparous and 73 were multiparous.

The primary outcome was time from induction to delivery. Secondary outcomes included time to active labor, delivery within 12 and 24 hours and cesarean delivery rate.

Researchers observed no difference in time from induction to delivery between women with obesity who received vaginal misoprostol 25 µg or 50 µg. Overall mean time to delivery was 18 hours. In a subgroup analysis, multiparous women with obesity had faster time to delivery with vaginal misoprostol 50 µg (11.97 vs. 15.19 hours; P = .03) compared with 25 µg.

For secondary outcomes, women in the 25 µg group had longer time to active labor compared with the 50 µg group, but this was not significant. Overall, 26.1% of women in the 25 µg group and 30.8% of women in the 50 µg group had delivery within 12 hours, and 61.1% of women in the 25 µg group and 71.4% of women in the 50 µg group delivered within 24 hours. Cesarean delivery rates were similar across both groups.

In addition, tachysystole occurred for 10.2% of women in the 25 µg group and 22% in the 50 µg group. Researchers observed no differences in maternal or neonatal adverse effects.

“Future research should move toward studies evaluating optimal labor management strategies in patients with obesity. It is well known that patients with obesity face an increased risk during labor and delivery, but there is a ‘one-size-fits-all’ model applied to obstetrics currently that does not take into account the individual aspects of the patient such as their BMI,” Saucedo told Healio. “There should be national multicenter collaboration to perform large studies to evaluate strategies aimed to reduce cesarean deliveries, time to vaginal delivery and improve delivery outcomes in patients with obesity.”

For more information:

Alexander M. Saucedo, MD, can be reached at alexander.saucedo@ascension.org.

Reference:

• Saucedo AM, et al. Am J Obstet Gynecol. 2024;doi:10.1016/j.ajog.2023.11.025.