Asphyxia and gestational age.

Perinatal asphyxia at term is a major cause of mortality and morbidity. In many instances obstetric or maternal complications during pregnancy, labor, or delivery account for the asphyxia, but there is a group of infants in whom asphyxia occurs without any recognizable risk factors. The histories of 1602 infants were evaluated with these problems in mind. There were 547 infants without any complicating factors, 329 with obstetric complications, and 356 with miscellaneous maternal, fetal, and neonatal problems. The mean gestational age of these infants was 277.4 days. Fetal distress was noted in 183 cases without subsequent neonatal disease; the mean gestation of these infants was 282.7 days. Unexpected intrapartum asphyxia was observed in 187 instances with a mean gestation of 288.8 days. Those who died or had neurologic symptoms had the longest mean gestation, 291 days. Only 5% of the infants dying of unexpected perinatal asphyxia and less than 16% of those with neurologic symptoms were born before their due dates; approximately 64% of the infants with obstetric complications, miscellaneous problems, or no complications or morbidity were born before 280 days. The implications for management of pregnancy at or beyond 280 days are discussed.