Association of Active Postnatal Care With Infant Survival Among Periviable Infants in the US.

Importance: Active postnatal care has been associated with center differences in survival among periviable infants. Regional differences in outcomes among periviable infants in the US may be associated with differences in active postnatal care. Objective: To determine if regions with higher rates of active postnatal care will have higher gestational age-specific survival rates among periviable infants. Design, Setting, and Participants: This cohort study included live births from 22 to 25 weeks' gestation weighing 400 to 999 g in the US Centers for Disease Control and Prevention (CDC) WONDER 2017 to 2020 (expanded) database. Infants with congenital anomalies were excluded. Active postnatal care was defined using the CDC definition of abnormal conditions of newborn as presence of any of the following: neonatal intensive care unit (NICU) admission, surfactant, assisted ventilation, antibiotics, and seizures. Data were analyzed from August to November 2022. Main Outcomes and Measures: Regional gestational age-specific survival rates were compared with rates of active postnatal care in the 10 US Health and Human Services regions using Kendall τ test. Results: We included 41 707 periviable infants, of whom 32 674 (78%) were singletons and 19 467 (46.7%) were female. Among those studied 34 983 (83.9%) had evidence of active care, and 26 009 (62.6%) survived. Regional rates of active postnatal care were positively correlated with regional survival rates at 22 weeks' gestation (rτ[8] = 0.56; r2 = 0.31; P = .03) but the correlation was not significant at 23 weeks' gestation (rτ[8] = 0.47; r2 = 0.22; P = .07). There was no correlation between active care and survival at 24 or 25 weeks' gestation. Regional rates of both NICU admission and assisted ventilation following delivery were positively correlated with regional rates of survival at 22 weeks' gestation (both P < .05). Regional rates of antenatal corticosteroids exposure were also positively correlated with regional rates of survival at 22 weeks' gestation (rτ[8] = 0.60; r2 = 0.36; P = .02). Conclusions and Relevance: In this cohort study of 41 707 periviable infants, regional differences in rates of active postnatal care, neonatal intensive care unit admission, provision of assisted ventilation and antenatal corticosteroid exposure were moderately correlated with survival at 22 weeks' gestation. Further studies focused on individual-level factors associated with active periviable care are warranted.