Outcomes of children of extremely low birthweight and gestational age in the 1990's

Advances in perinatal care have improved the chances for survival of extrem ely low birthweight (< 800 g) and gestational age (< 26 weeks) infants. A r eview of the world literature and our own experience reveals that at 23 wee ks gestation survival ranges from 2% to 35%. At 24 weeks gestation the rang e is 17% to 58%, and at 25 weeks gestation 35% to 85%. Differences in popul ation descriptors, in the initiation and withdrawal of treatment and the du ration of survival considered may account for the wide variations in the re ported ranges of survival. Major neonatal morbidity increases with decreasi ng gestational age and birthweight. The rates of severe cerebral ultrasound abnormality range at 23 weeks gestation from 10% to 83%, at 24 weeks from 17% to 64% and at 25 weeks gestation from 10% to 22%. At 23 weeks gestation , chronic lung disease occurs in 57% to 70% of survivors, at 24 weeks in 33 % to 89%, and at 25 weeks gestation in 16% to 71% of survivors, When compar ed to children born prior to the 1990's, the rates of neurodevelopmental di sability have, in general, remained unchanged. Of 30 survivors reported at 23 weeks gestation nine (30%) are severely disabled. At 24 weeks gestation the rates of severe neurodevelopmental disability (including subnormal cogn itive function, cerebral palsy, blindness and deafness) range from 17% to 4 5%, and at 25 weeks gestation 12% to 35% are similarly affected. In Clevela nd, Ohio, we compared the outcomes of 114 children with birthweight 500-749 g born 1990-1992 to 112 infants born 1993-1995. Twenty month survival was similar (43% vs 38%). The use of antenatal and postnatal steroids increased (10% vs 54% and 43% vs 84%, respectively, P < 0.001), however the rates of chronic lung disease increased from 41% to 63% (P = 0.06), There was a sig nificant increase in the rate of subnormal cognitive function at 20 months corrected age (20% vs 48%, P < 0.02) and a trend to an increase in the rate of cerebral palsy (10% vs 16%) and neurodevelopmental impairment. We concl ude that, with current methods of care, the limits of viability have been r eached. The continuing toll of major neonatal morbidity and neurodevelopmen tal handicap are of serious concern. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.