“…Maternal, sociodemographic, neonatal clinical, and NICU-related data were obtained through CPQCC records, using definitions as described in previous publications. 18,19 For the purposes of this analysis, prenatal care was defined categorically, maternal age was grouped as #19 years, 20-29 years, and subsequent 10 year intervals to 40+ years, and maternal race/ethnicity was categorized according to CCS guidelines (African American, Hispanic, white, Asian/Pacific Islander, native American, other). Other factors included morbidities that may have contributed to severity of illness, such as necrotizing enterocolitis (NEC), late sepsis, or meningitis (culture-proven sepsis and/or meningitis after day 3), surgery for retinopathy of prematurity, patent ductus arteriosus, or NEC, presence of congenital anomalies, oxygen use at 36 weeks postmenstrual age (PMA) (continuous or intermittent), and severe intraventricular hemorrhage (IVH).…”