Infants born before 29 weeks gestation: survival and morbidity at 2 years of age.

In a collaborative study involving two hospitals with large maternity services, 166 liveborn infants of gestational age from 24 to 28 weeks were born in the calendar years 1977 and 1978. Of these infants, 75 (45.2%) died either in hospital or after discharge home. At the age of 2 years, 16 (9.6%) of the cohort had a major handicap [cerebral palsy, Mental Developmental Index (MDI) under 69, deafness or blindness]. An additional 20 children (12.0%) had significant developmental delay (MDI 69 to 84, -2 to -1 SD below mean) and 53 (31.9%) were considered to be free of these handicaps. Psychological assessments were not performed on two survivors (1.2%) but reliable reports indicated that they were free of major handicaps. Long-term survival increased in a stepwise fashion from 9.1% at 24 weeks to 68.5% at 28 weeks gestation, and there was a trend for major handicap and significant developmental delay to decrease in incidence with increasing maturity. Of the 58 children who had presented by the vertex 42 (72.4%) were free of significant handicap; however, of the 31 children in whom there had been either a breech presentation or a transverse lie, only 11 (35.5%) were free of significant handicap (chi 2 = 9.69, P less than 0.01). The mode of delivery (vaginal or caesarean section) did not significantly affect the handicap rate in the survivors.