Association between risk-adjusted mortality and severe morbidity in very low birth weight infants: a multicenter study from the NEOCOSUR network

Marshall G.; Tapia J.L.; Dominguez A.; Fabres J.; González A.; D’Apremont I.; Mariani G.; Herbozo C.; Silvera F.; Vaz C. · Journal of Perinatology (2026) · DOI: 10.1038/s41372-026-02604-1

Resumen

Background: Very low birth weight infants (VLBWI) are at high risk of mortality and severe morbidities. While many neonatal networks monitor risk-adjusted outcomes separately, the relationship between mortality and major morbidities across centers remains unclear. Objective: To evaluate the association between risk-adjusted in-hospital mortality and six major morbidities in VLBWI across 20 South American NICUs participating in the NEOCOSUR Network between 2011 and 2023. Methods: Retrospective cohort study including 14,100 VLBWI (500–1500 g) from 20 NICUs in Argentina, Chile, Paraguay, Peru, and Uruguay. Observed-to-expected (O/E) ratios for mortality and for each morbidity—late-onset sepsis, bronchopulmonary dysplasia at 36 weeks (BPD), severe intraventricular hemorrhage (IVH grade III–IV), retinopathy of prematurity (ROP ≥ stage III), necrotizing enterocolitis (NEC ≥ stage II), and periventricular leukomalacia (PVL)—were calculated using logistic regression models adjusted for perinatal risk factors. Center-level associations were evaluated using Poisson regression models. Results: O/E mortality varied widely across centers (range from 0.62 to 1.48), with 7 centers showing significantly lower-than-expected mortality and 4 with higher-than-expected values. Significant positive associations were found between mortality O/E and O/E of late-onset sepsis (χ² = 53.6, p < 0.01), severe IVH (χ² = 18.0, p < 0.01), ROP (χ² = 38.0, p < 0.01), and PVL (χ² = 23.4, p < 0.01). An inverse association was observed between mortality and BPD (χ² = 36.2, p < 0.01). No significant association was found for NEC. Conclusions: Centers with higher-than-expected mortality also showed excess rates of several severe morbidities, suggesting that shared care practices may be associated with multiple outcomes. The inverse association with BPD may reflect a survival bias. These findings support the integration of multiple adjusted outcomes in quality benchmarking across NICUs. © The Author(s), under exclusive licence to Springer Nature America, Inc. 2026.

Instituciones: Universidad Peruana Cayetano Heredia