Changes in mortality in very preterm neonates in a single institution in Dallas, Texas, 1977–2024: a cohort study

BACKGROUND: Neonatal mortality has decreased during the last 50 yrs. To determine associations between changes in in-hospital mortality with race/ethnicity, gestational age (GA) and medical interventions, we studied very preterm neonates ( < 33wks GA, VPT). METHODS: This retrospective cohort study includes neonates born 22-32wks GA at Parkland Hospital, Dallas, TX January 1977-June 2024 and included in a validated, prospectively collected database. Neonates with congenital anomalies or absolute birthweight Z-score >5 were excluded. RESULTS: Overall, in-hospital mortality among 10,882 inborn VPT neonates decreased from 47.8% in 1977-1981 to 15.5% in 1987-1991 and 8.2% in 2023-2024. Mortality decreased 97-98% by 1986 in neonates 30-32wks GA and 92-93% by 1991 in neonates 27-30wks GA. Mortality in neonates 22-23wks GA remained >95% until 2010 and decreased 50% 2016-2024. Decreased mortality was associated with changes in prenatal and neonatal care. Although racial disparities in GA-specific mortality disappeared in 2009, higher mortality with male sex continued in 2024. CONCLUSIONS: Using a 47 yr database we documented serial decreases in in-hospital mortality in VPT neonates that are GA-dependent and occurred earliest in neonates 30-32wks GA, but not until after 2010 in those 22-23wks GA, paralleling changes in processes of maternal and neonatal care. Racial disparities in GA-specific mortality disappeared in 2009. IMPACT: Maintenance of a well-validated NICU database permits continuous assessment of local changes in care, their impact on local mortality/morbidity, and permits comparisons with national/international trends. In-hospital mortality decreased in association with changes in clinical care, first in neonates 32-33wks gestational age (GA) and last in those 22-23wks GA. Although racial disparity in mortality disappeared in 2009, higher mortality persisted in males. Long-term assessment of local changes in clinical care permits annual analysis of their impact on mortality/morbidity in comparison with neonatal/perinatal trends.