A Predictive Model for Intrapartum Cesarean Delivery in Multiparous Women After Active Labor Onset

OBJECTIVE: Although prediction models for cesarean delivery have been established for nulliparous women, few have been developed for multiparous women, particularly for predicting intrapartum cesarean delivery after the onset of active labor. This study aimed to develop and validate a risk prediction model for intrapartum cesarean delivery in this population and evaluate its clinical utility. METHODS: We conducted a retrospective case-control study at a single tertiary center (Suining Central Hospital, China) from January 2019 to June 2025. The study included 58 multiparous women who required cesarean delivery after active labor onset (cases) and 116 who had successful vaginal deliveries (controls). Candidate predictors included maternal age, prenatal body mass index, gravidity, parity, interdelivery interval, induction of labor, amniotic fluid characteristics, and fetal abdominal circumference. Predictors were identified through univariate analyses (Mann-Whitney U test for continuous variables, chi-square tests for categorical variables) followed by multivariate logistic regression. Model performance was evaluated by assessing discrimination (area under the receiver operating characteristic curve [AUC]), calibration (Hosmer-Lemeshow goodness-of-fit test), and internal validity (bootstrapping with 1000 replicates). A clinical nomogram was developed using R software (version 4.2.3) to facilitate practical application of the prediction model. RESULTS: The final model incorporated five independent predictors: prenatal BMI, induction of labor, interdelivery interval, fetal abdominal circumference, and amniotic fluid characteristics. The model demonstrated good discrimination, with an AUC of 0.82 (95% CI: 0.76-0.89). The Hosmer-Lemeshow test showed good calibration (p = 0.91), and bootstrap validation yielded a calibration slope of 0.92, indicating minimal overfitting. CONCLUSIONS: This novel prediction model, using readily available intrapartum variables, shows promise for identifying multiparous women at high risk of intrapartum cesarean delivery after active labor onset, potentially aiding clinical decision-making. External validation is warranted before clinical implementation.