Last modified: 2018-09-09
Abstract
OBJECTIVES: (1) To determine the association of small HC at birth with neurodevelopmental outcomes in neonates born at 24-32 weeks gestation; (2) To compare HC growth and Total Cerebral Volume (TCV) growth as predictors of outcomes.
METHODS: 150 preterm neonates were studied prospectively with HC measurements from birth and MRIs early in life and at term equivalent age. TCV was calculated using a semi-automated method. HC and TCV growth rates were calculated as percentage change per week. Outcomes were assessed at 3 years using Bayley III motor and cognitive scores. Multiple linear regressions were used to assess the association of HC & TCV with neurodevelopmental outcomes, accounting for gestational age at birth, brain injury, maternal education and postnatal illness.
RESULTS: 150 neonates had small HC at birth (<10th percentile), which predicted poorer motor (-7 points, p=0.020) and cognitive (-10 points, p<0.001) outcomes. Neonates whose small HC persisted to term had dramatically lower motor (-19 points, p=0.002) and cognitive scores (-16 points, p=0.005); neonates with small HC at birth that normalized by term had improved motor but not cognitive outcomes (-9 points, p=0.001). HC growth rate was only weakly correlated with TCV growth rate (r=0.54, p<0.001). TCV growth rate but not HC growth rate predicted motor outcomes (B=124.8, p=0.023). Neither HC nor TCV predicted cognitive outcomes (p>0.05).
CONCLUSIONS: The relationship between small HC at birth and adverse motor outcomes may be attenuated with normalization of head size and optimal brain growth in the early postnatal period.