We aimed to identify risk factors for cesarean section (C-section) in women with obesity undergoing induction of labor (IoL) with unfavorable cervix and develop a predictive score for the risk of C-section.

We conducted a single-center retrospective cohort study including all women with a body body mass index (BMI) ≥ 30 kg/m2), undergoing IoL with a Bishop score <6 between January 2013 and December 2019. Risk factors for C-section were identified using multivariate logistic regression analyses and a predictive score was derived from the regression coefficients. The performance of the score was assessed using area under the curve (AUC) and validated using k-fold cross-validation.

Among 863 included women, the C-section rate was 24.4% (n=211). Factors significantly associated with an increased risk of C-section were BMI ≥40 kg/m² (vs. 30–35 kg/m²: adjusted odds ratio [aOR]=1.9, 95% CI 1.0–3.7), height <160 cm (aOR=1.6, 95% CI 1.0–2.5), pre-existing diabetes (aOR=2.9, 95% CI 1.2–7.0), previous cesarean (aOR=4.2, 95% CI 1.9–8.9), and Bishop score (0–1 vs. 4–5: aOR=2.2, 95% CI 1.3–3.7). Lower risk of C-section was associated with parity (primiparous vs. nulliparous women: aOR=0.3, 95% CI 0.2–0.5) and term premature rupture of membranes (aOR=0.6, 95% CI 0.3–1.0). The predictive score demonstrated fair performance (AUC=0.77, 95% CI 0.73–0.81).

This predictive score enables estimation of the individual risk of cesarean section in women with obesity undergoing IOL. Its performance should be validated in an external cohort, and its clinical impact prospectively assessed.