Prematurely born babies who feed on breast milk have greater brain development, study finds

Prematurely born babies that feed on breast milk have greater brain development, according to a study published online this July in The Journal of Pediatrics. The findings highlighted greater deep nuclear gray matter and hippocampal volume as babies, as well as better performance on IQ, mathematics, working memory, and motor function tests at 7 years of age.

A pregnancy typically lasts 39-40 weeks (full-term), however, many babies are born prematurely (preterm). Preterm babies are classed as being born before 37 weeks into the pregnancy.

For full-term infants, breastfeeding seems to be beneficial to brain development. It has been proposed that this could be based on the specifics nutrients in breast milk or that infants receive greater sensitivity from the mother that provides breast milk.

Brain imaging research has attempted to shed light on the link between breast milk and brain development. For example, magnetic resonance imaging (MRI) has shown that early breastfeeding exposure leads to greater white matter development in full-term infants, as well as greater cortical thickness when they reached adolescence. However, the effects of breast milk and breastfeeding on brain development may be quite different in preterm infants.

The study, led by Mandy Belfort of Brigham and Women’s Hospital, looked at the potential benefits of breast milk intake on the brain development of very preterm infants. They studied 180 babies born at less than 30 weeks, or less than 1250 grams birth weight, and recorded the number of days on which babies received more than 50% of enteral intake (tube feeding) as breast milk in their first 28 days of life.

Brain volumes were measured by MRI after term equivalent (the age at which they would have been born had they not been premature) and 7 years of age. Further measures of cognitive (IQ, reading, mathematics, attention, working memory, language, visual perception) and motor testing were taken at 7 years of age.

The results revealed that breast milk intake in the preterm infants was associated with greater brain development (deep nuclear gray matter volume and hippocampal volume) at term age equivalent. Breast milk intake was also associated with better performance at 7 years of age on IQ, mathematics, working memory, and motor function tests – but there were no brain volume differences at 7 years of age.

The researchers concluded, “These results provide support for national and international recommendations to provide breast milk as the primary diet for preterm infants.”