(239) Maternal and Infant Morbidity in Relation to Caesarean Section in a Large Commercially Insured Population in The US in 2019 and 2020

Publication Number: 570

Background: Approximately one third of deliveries in the US are by Caesarean section (CS), and usage of the procedure varies greatly in the US and globally. Whether medically indicated or elective, a CS delivery poses potential risks to mothers and infants, and characterization of these risks using more recent data is needed to inform families, clinicians, and policy makers of the current risks and benefits of the procedure.

Objectives: Investigate maternal and infant morbidity up to one year in relation to delivery mode (CS, vaginal) in a large population of commercially insured US patients with births in 2019 and 2020.

Methods: Within a healthcare claims database of patients commercially insured by Anthem, Inc. affiliated health plans, we compared measures of maternal and infant morbidity by delivery mode. We extracted claims for delivery mode, outcomes, and supporting variables from the patients’ claims data in 2019 and 2020. Maternal morbidity measures included 20 CDC Severe Maternal Morbidity (SMM) outcomes, plus depression, postpartum depression, and hemorrhage. Infant morbidity measures included select outcomes previously reported to be associated with delivery mode, including eight outcomes related to respiratory health, digestive health, atopy, and birth trauma. Infant outcomes were analyzed overall and stratified by gestational age at birth. Time periods of interest included delivery through 42 days and 360 days . Statistical analyses included comparisons of the incidence and odds ratio (OR) of the outcome measures adjusted for select covariates, which included baseline risk factors. Analyses for 2019 and 2020 cohorts were conducted separately to account for variable follow-up and potential influence of the COVID-19 pandemic.

Results: A total of 434,544 deliveries were identified in the study period (2019: 73,106 CS, 147,372 vaginal; 2020: 71,242 CS, 142,824 vaginal). In covariate-adjusted models in the 2019 cohort, the incidence of SMM was higher among CS than vaginal deliveries at both 42 days (5.6% vs 2.4%; OR 2.02, 95% CI: 1.93, 2.13) and 360 days (6.5% vs 3.0%; OR 1.86, 95% CI 1.78, 1.95). Remaining outcomes were similarly more common among CS deliveries at both time points, except for hemorrhage. Risk of 1-year infant morbidity in the 2019 cohort was higher among CS vs vaginal deliveries (27.7% vs. 23.6%; OR 1.20, 95% CI: 1.17-1.22). Incidence of morbidity was higher in CS vs vaginal delivers for both full-term (27.7% vs. 23.6%) and preterm infants (56.7% vs 41.8%). Similar trends were observed in the 2020 cohorts.

Conclusions: Our study, performed using recent data obtained from a large US healthcare claims database, provides contemporary evidence of potential risks to mothers and infants of CS delivery relative to vaginal delivery.