Sex-specific relationships between early nutrition and neurodevelopment in preterm infants

Although early nutrition is associated with neurodevelopmental outcome at 2 years’ corrected age in children born very preterm, it is not clear if these associations are different in girls and boys. Retrospective cohort study of infants born <30 weeks’ gestational age or <1500 g birth weight in Auckland, NZ. Macronutrient, energy and fluid volumes per kg per day were calculated from daily nutritional intakes and averaged over days 1–7 (week 1) and 1–28 (month 1). Primary outcome was survival without neurodevelopmental impairment at 2 years corrected age. More girls (215/478) survived without neurodevelopmental impairment at 2 years (82% vs. 72%, P = 0.02). Overall, survival without neurodevelopmental impairment was positively associated with more energy, fat, and enteral feeds in week 1, and more energy and enteral feeds in month 1 (P = 0.005–0.03), but all with sex interactions (P = 0.008–0.02). In girls but not boys, survival without neurodevelopmental impairment was positively associated with week 1 total intakes of fat (OR(95% CI) for highest vs. lowest intake quartile 62.6(6.6–1618.1), P < 0.001), energy (22.9(2.6–542.0), P = 0.03) and enteral feeds (1.9 × 109(9.5–not estimable), P < 0.001). Higher early fat and enteral feed intakes are associated with improved outcome in girls, but not boys. Future research should determine sex-specific neonatal nutritional requirements.