Present status of the infant of very low birth weight treated in a referral neonatal intensive care unit in 1974.

In 1974, 250 infants with birth weights of 1500 g or less were referred to the Intensive Care Unit at the Hospital for Sick Children, Toronto. Sixty-six per cent survived. Prospective follow-up studies of the survivors have been completed over a minimum of two years. Infants at highest risk for handicapping defects (about 85%) are those who survived intracranial haemorrhage during the neonatal period. Neurological defects encountered in these children were severe--hydrocephalus, spastic quadriplegia, hemiplegia or microcephalus--and were usually associated with low psychometric scoring. The second highest risk group were small for gestational age infants. Of these, 53% were significantly handicapped at two years of age, and 43% had developmental quotients of less than 80. These defects could not be related to postnatal events. The third category at high risk were infants with birth weights of 1000 g or less. Among these, 30% had a significant handicap by two years of age. The outcome in the remainder of the sample was generally good. These results suggest that the decreased mortality of the very premature infant is associated with an increased number of relatively normal survivors and that the infants at highest risk for subsequent defects can be identified at or shortly after birth.