Perinatal and Environmental Factors in Late Neurogenic Sequelae

MANY STUDIES have shown that one third to one half of all infants with birth weights on the order of 1,500 gm or less either do not attain a normal intellectual level or have some neurologic defect or behavior difficulty.¹⁻¹⁰The results of these studies together with current birth rates suggest that approximately 10,000 children born in the United States each year in this low weight group are destined to be chronically handicapped. Considerable evidence exists from previous studies that the incidence of these late sequelae is inverse to birth weight and socioeconomic status. The role of perinatal factors is less well established. Some of the earlier studies omitted all reference to neonatal difficulties, especially those associated with hypoxia. In other investigations data on respiratory distress and oxygenation were obtained retrospectively. Furthermore, previous studies were carried out during the era when oxygen was used in unrestricted concentrations and there