Moving beyond overall cesarean rates: Evaluating associations of delivery mode and adverse outcomes by Robson Group among the PRISMA Maternal and Newborn Health Study cohort in sub-Saharan Africa and South Asia

Objective: Rising cesarean section (CS) rates in low- and middle-income countries may mask a triple burden of unmet need, overuse, and unsafe provision. Using the Robson Ten-Group Classification, a global standard for monitoring and comparing institutional deliveries, we examine CS incidence and associations with adverse outcomes. Methods: Data were drawn from the Pregnancy Risk, Infant Surveillance, and Measurement Alliance Maternal and Newborn Health Study, an open cohort study conducted from 2022 to 2025 in Kenya, Zambia, India, and Pakistan. We generated descriptive statistics for Robson Groups and within-group relative risks of adverse events for CS versus vaginal delivery using multivariable adjusted log Poisson models. Results: Among 10,996 women, 29% delivered by CS. Group 5 (prior CS) and Group 10 (preterm) were the largest contributors to CS, accounting for 28% and 17% of all CS deliveries, respectively. Between-site differences in CS incidence were most pronounced for Groups 2 and 4 (induced labor/pre-labor CS), ranging from 20-60% for nullipara and 7-44% for multipara. Compared to vaginal delivery, CS was associated with increased risk of maternal near-miss, prolonged hospitalization, hemorrhage, and newborn intensive care unit admission. These associations differed in magnitude when stratified by Robson Group, with the greatest risk among lower-risk groups. Conclusion: Repeat CS, preterm deliveries, labor induction, and pre-labor CS were key drivers of CS, with considerable differences between sites. Equipping facilities to safely manage labor induction, trials of labor after cesarean, and preterm deliveries is critical to improving quality of care.