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Oral Concurrent Session 8 - Labor & Delivery

Oral Concurrent Sessions

(82) Obesity remains associated with cesarean delivery despite a standardized protocol for labor induction

Wednesday, February 14, 2024
4:45 PM – 5:00 PM  
Location: Potomac Ballroom C, Ballroom Level
Foundation Awardee
Objective:

Patients with obesity are at increased risk for cesarean delivery (CD), with failed induction of labor (IOL) as a leading indication. Possible explanations for differences in CD include physiologic differences and variation in provider care. We aimed to evaluate CD for patients with obesity before and after implementation of a standardized protocol for IOL. We hypothesized that if differences in CD remained after standardizing labor induction, this would support factors other than variations in care contributing to the risk, such as underlying biological factors.

Study Design:

This is a secondary analysis of a prospective cohort study conducted at 2 sites comparing 2 years before (PRE) to 2 years after (POST) implementation of an IOL protocol from 2018-2022. This analysis included term, nulliparous, singleton gestations undergoing IOL with unfavorable cervices, intact membranes, and BMI ≥30 kg/m2 at delivery. The standardized IOL protocol recommended active labor management, including frequent cervical exams, amniotomy by first exam ≥4cm, and intervention when no cervical change was made after two hours (e.g. oxytocin and IUPC). Patients were stratified by obesity class: 30-34.9; 35-39.9; ≥40. The primary outcome was CD. Poisson regression with robust error variance was used to calculate adjusted relative risks (aRR).

Results:

5131 patients were included (PRE: n=2480, POST: n=2651). While patients in the POST group had increased maternal age, less favorable cervical exams, differences in IOL indication, and cervical ripening agent used, there was no difference in BMI class. There were no differences in risk of CD in any obesity class from PRE to POST implementation, even when controlling for confounders (Table). There were also no differences in labor length, maternal, or neonatal morbidity in any obesity class from PRE to POST-implementation.

Conclusion:

In this work, minimizing variation in IOL management did not impact the relationship between obesity and CD, supporting underlying physiologic explanations.