Association between neonatal morbidities and head growth from birth until discharge in very-low-birthweight infants born preterm: a population-based study

Aim: To evaluate the possible association between major neonatal morbidities and poor head growth from birth to discharge home in very-low-birthweight (VLBW) infants born preterm. Method: Population-based observational study comprising 12 992 infants (6340 male, 6652 female) of 24 to 32 weeks' gestation, and birthweight ≤1500g. Severe head growth failure (HGF) was defined as a decrease in head circumference z-score >2 z-scores, and moderate HGF as a decrease of 1 to 2 z-scores. Multinomial logistic regression analysis was applied to determine morbidities associated with HGF. Results: Severe HGF occurred in 4.5% and moderate HGF in 20.9% of infants. Each unit increase in head circumference z-score at birth was associated with increased odds for severe and moderate HGF (odds ratios [OR] 5.29, 95% confidence intervals [CI] 4.67–6.00, and OR 2.38, 95% CI 2.23–2.54 respectively). Both severe and moderate HGF were associated with respiratory distress syndrome (OR 2.03, 95% CI 1.58–2.62, and OR 1.66, 95% CI 1.48–1.85 respectively); bronchopulmonary dysplasia (OR 3.38, 95% CI 2.33–4.91, and OR 1.87, 95% CI 1.52–2.30 respectively); necrotizing enterocolitis (OR 2.89, 95% CI 2.04–4.09, and OR 1.72, 95% CI 1.38–2.16 respectively), and sepsis (OR 2.06, 95% CI 1.69–2.50, and OR 1.38, 95% CI 1.24–1.53 respectively). Interpretation: Major neonatal morbidities were associated with HGF in VLBW infants born preterm. Identification of whether this is a direct effect of these morbidities or mediated through nutritional or growth factors may enable interventions to improve postnatal head growth of infants born preterm.