Head Growth Trajectory and Neurodevelopmental Outcomes in Preterm Neonates.

Objectives: To evaluate the association between head growth (HG) during neonatal and postdischarge periods and neurodevelopmental outcomes of preterm neonates of <29 weeks gestational age.

Methods: 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.

Results: 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.

Conclusions: Poor HG during the neonatal and postdischarge periods was associated with motor and cognitive delays at 16 to 36 months.