It has well been accepted that breastfeeding is the best method for feeding healthy, full term infants and is beneficial to neurodevelopment, either because of specific nutrients found in breast milk that are not found in formula, or because of increased maternal sensitivity shown by mothers who breastfeed. However, these effects may be quite different in extremely premature infants, as these infants require fortification to match nutrient accretion rates of the third trimester. This study therefore aimed to investigate the relationship between breast milk consumption during the neonatal hospitalization period and brain magnetic resonance imaging (MRI) characteristics at term equivalent age (the age at which they would have been born had they not been premature) and 7 years of age, along with neurodevelopmental outcomes at 2 and 7 years of age.

To investigate this, infants born at <30 weeks’ gestation or <1250 grams birth weight were recruited from the Royal Women’s Hospital in Melbourne, Australia. The daily volume of breast milk and formula intake was taken from medical records for the first 28 days of life and the number of days on which the infant received breast milk as >50% of their feedings was calculated. Participants underwent brain MRI at term equivalent age and 7 years of age to get imaging of their brain. Neurodevelopmental assessments were also administered at 2 years of age to measure cognition and motor skills and at 7 years of age to measure general intelligence, academic achievement, attention, working memory, language, visual perception and motor function.

It was found that for each additional day on which breast milk was >50% of intake, there was a proportional increase in the deep nuclear grey matter volume and hippocampal volume of the brain at term equivalent age and 7 years of age. These areas of the brain are involved in effective neural functioning and in memory and learning, respectively. These results were confirmed with the neurodevelopmental assessments given at 7 years of age, as it was also found that increased breast milk consumption was associated with verbal and performance IQ, math computation and working memory at age 7.

These findings about the associations of breast milk and increased deep nuclear grey matter and hippocampal volume may help to distinguish the mechanisms by which breastfeeding influence later neurodevelopment. These results also provide support for the national and international recommendations that breast milk should be offered as the primary diet for preterm infants.

Source:

Belfort, M.B., Anderson, P.J., Nowak, V.A., Lee, K.J., Molesworth, C., Thompson, D.K., … Inder, T.E. (2016). Breast milk       feeding, brain development, and neurocognitive outcomes: A 7-year longitudinal study in infants born at less than 30 weeks’ gestation. The Journal of Paediatrics, 177, 133-139.