Improvement of outcome for infants of birth weight under 1000 g. The Victorian Infant Collaborative Study Group.

The two year outcome of extremely low birth-weight (ELBW) infants (birth weight 500 to 999 g), born in the state of Victoria over two distinct eras, 1979-80 and 1985-7, were compared. In the 1979-80 era, 25.4% of the ELBW infants survived to 2 years of age; only 12.5% of liveborn ELBW infants survived to 2 years with no neurological disabilities. In the 1979-80 era, ELBW infants born outside the level III centres in the state were significantly disadvantaged in both mortality and neurological morbidity. By 1985-7, the two year survival rate of ELBW infants rose significantly from 25.4% to 37.9%. By 1985-7, the proportion of ELBW infants who survived to 2 years free of neurological disabilities increased from 12.5% to 26.2%. Despite the improved survival, the absolute number of 2 year old children survivors with severe neurological disabilities remained constant at 8/year in both eras. By 1985-7, fewer ELBW infants were born outside the level III centres, their survival rate remained lower, but the severe neurological disability rate in survivors was no longer significantly higher. There has been a concomitant improvement in both survival and reduction in neurological morbidity.