Compelling evidence links more prolonged and exclusive breastfeeding in infancy with improved neurodevelopmental outcomes in childhood.
1,2 Postulated mechanisms include nutrients and nonnutrient bioactive factors in maternal milk that benefit the infant brain during a critical period in development.
3 Whether breastfeeding offers similar benefits to infants born very preterm (<32 weeks of gestation) is less certain. Findings from studies of full-term infants are not directly generalizable to the very preterm population given substantial differences in postnatal nutrient requirements
4 and neurodevelopmental risk profiles.
5 Furthermore, the very preterm infant is fed expressed maternal milk during the several-months-long period from preterm birth to term equivalent age, a period of susceptibility to brain injury
6 and one that coincides with an earlier stage of brain development than when the full-term infant is fed maternal milk. It is plausible that maternal milk may have different effects at different stages of brain development. Furthermore, within cohorts of preterm infants, the beneficial effect of maternal milk may vary by gestational age and fetal growth status as well as by infant sex.