Nulliparous with Class III Obesity at Term: Labor Induction or Cesarean Delivery without Labor.

Abstract

Objective:  This study aimed to compare maternal and neonatal outcomes between labor induction versus cesarean delivery (CD) without labor among nulliparous individuals with class III obesity (body mass index [BMI] ≥40 kg/m²).

Study design:  A retrospective cohort study of all nulliparous singleton deliveries at ≥37 weeks with a BMI of ≥40 kg/m² at delivery between March 2020 and February 2022. We excluded individuals with spontaneous labor, fetal malformations, and stillbirths. The primary outcome was a composite of maternal mortality and morbidity, including infectious and hemorrhagic morbidity. The secondary outcome was a neonatal composite. A subgroup analysis evaluated patients with a BMI of ≥50 kg/m². Another subgroup analysis compared outcomes between CD without labor and an indicated CD following induction. A multivariable logistic regression was applied. For adjustment, we used possible confounders identified in a univariate analysis.

Results:  Among 8,623 consecutive deliveries during the study period, 308 (4%) met the inclusion criteria. Among them, 250 (81%) underwent labor induction, and 58 (19%) had a CD without labor. The most common indications for CD without labor were fetal malpresentation (26; 45%), suspected macrosomia (8; 14%), and previous myomectomy (5; 9%). Indicated CD occurred in 140 (56%) of the induced individuals, with the two leading indications being labor arrest (87; 62%) and non-reassuring fetal heart rate tracing (51; 36%). The rates of composite maternal morbidity (adjusted odds ratio [aOR] = 2.14, 95% confidence interval [CI]: 0.64-7.13) and composite neonatal morbidity (aOR = 3.62, 95% CI: 0.42-31.19) did not differ following a CD without labor compared to labor induction. The subgroup analyses did not demonstrate different outcomes between groups.

Conclusion:  Among nulliparous individuals with class III obesity at term who underwent induction, more than 50% had indicated CD; the rate of short-term maternal and neonatal morbidity, however, did not differ between labor induction and CD without labor.

Key points: · The rate of unplanned CD among those who underwent labor induction was relatively high (56.0%).. · Outcomes did not differ between those who underwent CD without labor and those who were induced.. · Outcomes also did not differ between those who underwent CD without labor and those with CD in labor..