the cognitive development at 2 and 5 years of a cohort of extremely low birthweight ( elbw ) children ( birthweight 500-999 g ) was compared with that of cohorts of larger very low birthweight ( vlbw ) children ( birthweight 1000-1500 g ) and normal birthweight ( nbw ) children ( birthweight greater than 2500 g ) to determine whether the improvements in cognitive function of elbw infants between 2 and 5 years are apparent or real .
C0282666
very low birthweight
C0005612
birthweight