Early neonatal deaths with perinatal asphyxia of newborns ≥ 37-weeks in Brazil, 2000‒2020

Objective  To evaluate temporal and geographical trends of early Neonatal Mortality Rate (NMR) associated with perinatal asphyxia in newborns ≥ 37-weeks’ gestation without congenital anomalies in Brazil, from 2000 to 2020.

Method  The database was built based on live birth and death certificates, according to the municipality where birth occurred. Perinatal asphyxia was considered if ICD-10 codes were present in any line of the death certificate: intrauterine hypoxia (P20), birth asphyxia (P21) or neonatal aspiration of meconium (P24.0). Prais-Winsten method tested the temporal trend of early NMR associated with perinatal asphyxia per thousand live births. The geographical distribution was analyzed by municipality.

Results  Over the 21 years, 55,204,633 live births were ≥ 37-weeks’ gestation without congenital anomalies, and 35,443 died with perinatal asphyxia up to day 7 of postnatal life. Early NMR associated with perinatal asphyxia decreased from 0.86 in 2000 to 0.45 in 2020 (annual change: -3.23%; 95% CI: -4.16% to -2.29%). This reduction was observed in all regions of the country, but North and Northeast showed, in 2020, rates above those found in 2000 in Southeast, South, and Midwest. The number of municipalities with early NMR associated with perinatal asphyxia >1.50 in Brazil decreased from 482 vs. 200 in 2000‒2005 vs. 2016‒2020.

Conclusion  Since 2000, there has been a significant decline in early neonatal mortality rates associated with perinatal asphyxia among infants born at ≥ 37-weeks’ gestation without congenital anomalies in Brazil. However, in 2020, 0.45 per 1,000 of these live births still resulted in death, with marked regional disparities persisting.

Keywords
Infant; Newborn; Neonatal mortality; Developing countries; Epidemiological studies; Asphyxia neonatorum