(166) Intrapartum Cesarean Delivery in PPROM: Identifying Key Risk Factors and Developing a Predictive Model

We conducted a retrospective cohort study at a university-affiliated tertiary medical center with approximately 12,500 deliveries annually (2012-2023). The study included women with P-PROM who planned a trial of labor, excluding those opting for elective CD or with non-viable fetuses.  We compared maternal and neonatal characteristics between those who delivered vaginally and those who underwent intrapartum CD. Risk factors were identified using univariate and multivariate logistic regression analyses. A predictive risk score was developed based on the relative risk of each factor, with model performance assessed using the ROC curve. 

Results:

1. During the study period, 145,833 women delivered at our center. Of these, 1,494 (1%) were admitted with P-PROM and were eligible for analysis.

2. Among these, 470 (31.5%) underwent intrapartum CD, with a median gestational age of 34.5 weeks (IQR 32.3, 36.0) compared to 35.4 weeks (IQR 33.5, 36.4) in women who delivered vaginally.

3. Multivariate analysis revealed that maternal age > 40 years, multiple gestations, and previous CD are independent risk factors for intrapartum CD. Conversely, BMI > 30, use of oxytocin or antibiotics during labor, and spontaneous onset of labor were protective factors. We assigned risk scores to each factor and incorporated them into our model. [Table 2].

4. The developed risk score model, with a cut-off of 7, predicted intrapartum CD with an area under the curve of 0.85 (95% CI [0.80-0.88], p< 0.001), demonstrating 70% sensitivity and 80% specificity.

Conclusion:

Utilizing our risk score to assess factors before and during labor can aid clinicians in making more informed decisions regarding the risk for intrapartum CS in women with P-PROM.