Neonatal asphyxia. I. Relationship of obstetric and neonatal complications to neonatal mortality in 38,405 consecutive deliveries.

The requirement of greater than one minute of positive pressure ventilation was prospectively used to identify infants suffering from asphyxia at birth in 38,405 consecutive deliveries. Multivariate analysis of high-risk factors associated with increased risk of asphyxia showed the prematurity was the most significant predictor of asphyxia. Asphyxia occurred in 62.3% of infants less than 27 weeks' gestation and decreased to 0.4% in infants greater than 38 weeks' gestation. Presence of asphyxia was associated with significant increase in neonatal mortality of infants greater than 36 weeks' gestation. Of the asphyxiated neonates, growth retardation, hypothermia, hyaline membrane disease, and seizures were significantly associated with an increased risk of death.