Maternal and Neonatal Outcomes Associated With Cesarean Versus Vaginal Delivery in the United States: A Population-Based Retrospective Cross-Sectional Analysis of CDC Natality Public Use Data (2017-2020)

Background: Cesarean delivery is a common obstetric procedure in the United States, yet concerns remain regarding its association with maternal and neonatal outcomes at the population level. Understanding outcome patterns by mode of delivery is important for informing clinical practice and public health planning. Objective: To examine population-level associations between mode of delivery and severe maternal morbidity (blood transfusion, uterine rupture, unplanned hysterectomy, or maternal intensive care unit admission) and adverse neonatal outcomes (neonatal intensive care unit admission, assisted ventilation, or infant transfer) among live births in the United States. Methods: This retrospective cross-sectional study analyzed the Centers for Disease Control and Prevention (CDC) Natality public use microdata from 2017 to 2020, including all recorded live births during the study period. The mode of delivery was categorized as cesarean or vaginal. Severe maternal morbidity and adverse neonatal outcomes were defined using composite indicators derived from reported clinical variables. Multivariable logistic regression was used to estimate adjusted odds ratios (aORs) while controlling for maternal demographic characteristics, clinical comorbidities, obstetric factors, and year of delivery. Robust standard errors were applied. Results: Among the 15,035,328 births included in the analysis, severe maternal morbidity occurred in 32,630 (0.32%) vaginal deliveries compared with 55,463 (1.16%) cesarean deliveries (p < 0.001). The composite adverse neonatal outcome was observed in 770,413 (7.52%) vaginal deliveries and 903,895 (18.88%) cesarean deliveries (p < 0.001). In multivariable analyses adjusting for maternal demographic characteristics, clinical comorbidities, obstetric factors, and year of delivery, cesarean delivery was associated with higher odds of severe maternal morbidity compared with vaginal delivery (aOR, 2.99; 95% CI, 2.94-3.04). Cesarean delivery was also associated with higher odds of adverse neonatal outcomes (aOR, 2.19; 95% CI, 2.19-2.20). Preterm birth demonstrated a strong association with adverse neonatal outcomes (aOR, 13.87; 95% CI, 13.81-13.93). Conclusion: Cesarean delivery was associated with higher maternal and neonatal morbidity in this national analysis. These associations likely reflect, in part, underlying obstetric complexity and high-risk clinical conditions that contribute both to the decision for cesarean delivery and to adverse outcomes. These findings emphasize the importance of careful clinical decision-making and continued efforts to improve maternal and neonatal care in high-risk pregnancies.