Head Growth Trajectory and Neurodevelopmental Outcomes in Preterm Neonates.

Abstract

To evaluate the association between head growth (HG) during neonatal and postdischarge periods and neurodevelopmental outcomes of preterm neonates of <29 weeks gestational age. We conducted a retrospective cohort study of infants <29 weeks gestational
age admitted between 2009 and 2011 to participating Canadian Neonatal Network
units and followed by Canadian Neonatal Follow-Up Network clinics. Differences in head circumference (ΔHC) z score were calculated for 3 time periods, which include admission to discharge, discharge to follow-up at 16-36 months, and admission to follow-up. These were categorized in 1 reference group (ΔHC z score between -1 and +1) and 4 study groups (ΔHC z score of <-2, between -2 to -1, +1 to +2, and >+2). Neurodevelopmental outcomes were compared with the reference group. 1973 infants met the inclusion criteria. Poor HG occurred frequently during the NICU admission (ΔHC z score <-2 in 24% infants versus 2% infants post-discharge) with a period of "catch-up" growth postdischarge. Significant neurodevelopmental impairment was higher in infants with the poorest HG from admission to follow-up (adjusted odds ratio 2.18, 95% confidence interval 1.50-3.15), specifically cognitive and motor delays. Infants with poor initial HG and catch-up postdischarge have a lower adjusted odds ratio of significant neurodevelopmental impairment (0.35, 95% CI 0.16-0.74). Infants with poor HG received a longer duration of parenteral nutrition and mechanical ventilation and had poor weight gain. Poor HG during the neonatal and postdischarge periods was associated with motor and cognitive delays at 16 to 36 months.