In a cohort of 1070 infants born between 23 and 27 weeks' gestation, we examined weight gain from 7-28 days of life (in quartiles) and weight
Weight gain in the lowest quartile from 7-28 days was not associated with higher risk of adverse outcomes. Children with a 12-month weight z-score <−2 were at increased risk for all adverse outcomes in girls, and for microcephaly and Gross Motor Function Classification System ≥1 in boys. However, excluding children with motor impairment attenuated all associations except that of weight z-score <−2 with microcephaly in girls. Similarly, most associations of low weight z-score at 24 months with adverse outcomes were attenuated with exclusion of children with motor impairment.
Excluding children who have gross motor impairment appears to eliminate the association of low weight status with neurodevelopmental impairments at 2 years in extremely preterm infants.