First- and fifth-minute Apgar scores of 0-3 and infant mortality: a population-based study in São Paulo State of Brazil.

Abstract

To determine the infant mortality of newborns with 1- and 5-min Apgar scores of 0-3. Population cohort study with neonates with birth weight ≥400 g, gestational age ≥22 weeks and 1- and 5-min Apgar scores of 0-3, without malformations, born in São Paulo State (Brazil) from January 2006 to December 2007. Apgar scores were confirmed in the original certificates of live births and/or medical records. During this period, among 1,027,132 live births, 1640 met the study criteria, with an incidence of 1.6 per 1000 live births. When the 5-min Apgar score was 0, 1, 2 and 3, the infant mortality rate was 97%, 94%, 64% and 47%, respectively. Risk factors associated with infant deaths were 5-min Apgar score of 0 or 1 [odds ratio (OR) 16.6, 95% confidence interval (CI) 11.1-24.8], birth weight <2500 g (OR 7.5, 95% CI 5.7-9.8), birth at hospitals outside the state capital (OR 1.7, 95% CI 1.3-2.3), in private or charitable hospitals (OR 1.6, 95% CI 1.2-2.0), and during the night shift (OR 1.3, 95% CI 1.0-1.7). For infants with 1- and 5-min Apgar scores of 0-3, the infant mortality is high. Besides the biological variables associated with the chance of dying, the organization of the perinatal care influences the outcome.