Care-mediated inequalities in neonatal vitality: a population-based record linkage study in southern Brazil

Background Persistent inequalities in neonatal outcomes in middle-income settings raise questions about the role of healthcare systems in shaping health disparities. Beyond population characteristics, differences in how obstetric care is delivered may contribute to unequal outcomes. Methods We conducted a population-based analytical study using deterministic record linkage between the Brazilian Live Birth Information System (SINASC) and the Mortality Information System (SIM) from 2017 to 2024 in a municipality in southern Brazil. Neonatal vitality was assessed using low Apgar score at 1 minute (≤ 7) and neonatal mortality. Maternal race (white vs. non-white), mode of delivery, and obstetric context (Robson classification aggregated into macro-groups) were analyzed. Logistic regression models estimated adjusted associations and tested interaction effects. Results The study included 32,650 live births and 157 neonatal deaths. Prematurity (OR ≈ 4.3) and low birth weight (OR ≈ 12.9) were the strongest predictors of adverse outcomes. Vaginal delivery was associated with higher odds of low Apgar score than cesarean section (OR ≈ 1.48; 95% CI 1.06–2.06). Maternal race showed a positive but non-significant association after adjustment. Significant interactions were observed between obstetric context and mode of delivery (p = 0.003), and between mode of delivery and maternal race (p < 0.001), indicating that disparities vary across care pathways. The three-way interaction was not statistically significant. Conclusions Neonatal inequalities are structured through care-mediated pathways in which clinical decisions interact with social position. These findings suggest that improving equity in perinatal health requires not only expanding access but also addressing how care is delivered and how decisions are made within obstetric settings.