Background: The effect of human milk intake on neurodevelopment in preterm infants is uncertain.
Methods: We analyzed data from 611 participants in the DHA for Improvement of Neurodevelopmental Outcomes study, enrolled at ≤33 wk gestation from five Australian perinatal centers. The main exposures were (i) average daily human milk intake during the neonatal hospitalization and (ii) total duration of human milk intake before and after discharge. Outcomes were Bayley Scales of Infant Development, 2nd Edition Mental (MDI), and Psychomotor (PDI) Development Indexes.
Results: Adjusting for confounders in linear regression, human milk intake was not associated with higher MDI (0.2 points per 25 ml/kg/d; 95% confidence interval (CI): -0.6, 1.0) or PDI (-0.3 points; 95% CI: -1.1, 0.4). Longer duration of human milk intake was also not associated with MDI (0.1 points per month; 95% CI: -0.2, 0.3) or PDI (-0.2 points per month; 95% CI: -0.5, 0.01) scores, except in infants born 29-33 wk gestation (n = 364, MDI 0.3 points higher per additional month, 95% CI: 0.1, 0.6).
Conclusions: We found no associations of human milk intake during the neonatal hospitalization with neurodevelopment at 18 mo corrected age.