Summary: Many babies born preterm have underdeveloped cerebral cortices, the brain region crucial for learning and cognition. A new study finds that preterm infants who received larger volumes of breast milk during their stay in neonatal intensive care showed cortical development that more closely resembled that of term-born infants. Researchers suggest that increased exposure to breast milk may help reduce the learning and behavioral problems commonly associated with preterm birth.
Source: University of Edinburgh
Feeding more breast milk to premature infants in neonatal care is linked with better brain development, new research indicates.
The cerebral cortex—the outer layer of the brain responsible for higher cognitive functions such as thinking, learning and memory—tends to be less mature in babies born preterm. The study reports that preterm infants who received higher amounts of breast milk, whether from their own mothers or from donors, displayed cortical features at term-equivalent age that more closely matched those of babies born at full term.
Researchers say that supporting and facilitating breast milk feeding in neonatal intensive care units could be an effective strategy to help reduce the developmental, cognitive and behavioral difficulties that often follow preterm birth.
Globally, about 15 million babies are born before 37 weeks of gestation each year, and prematurity remains a leading cause of neonatal death and long-term disability. Children born preterm face increased risk of lifelong challenges, including learning difficulties, sensory impairments, behavioral disorders and cerebral palsy.
This study scanned the brains of 212 infants who took part in the Theirworld Edinburgh Birth Cohort, a long-term project that follows babies born prematurely from birth into later life. The cohort included 135 infants born before 32 weeks’ gestation and 77 infants born at term. Feeding records documented the extent of breast milk exposure during each preterm infant’s stay in neonatal intensive care, and MRI scans were performed for all infants at around 40 weeks post-conception (term-equivalent age).
Analysis of the MRI data revealed that preterm infants with higher cumulative exposure to breast milk had cortical measures—such as volume, thickness and diffusion characteristics—more similar to term-born controls than preterm infants who received less breast milk. These imaging features are consistent with more mature cortical development.
Supporting development
Breast milk contains a balanced mix of fats, proteins and minerals, along with numerous bioactive factors that support immune function and may influence neural development. While the precise biological mechanisms remain to be established, these nutritional and immunological components are plausible contributors to the observed association between breast milk exposure and cortical maturation in preterm infants.
The research team emphasizes the need for further studies to identify which elements in breast milk drive these effects and to understand how nutritional interventions could best support brain growth after preterm birth.
“Our findings suggest that brain development in the weeks following preterm birth is improved in infants who receive greater amounts of breast milk,” says Dr. Gemma Sullivan. “Mothers of preterm babies should be supported to express breast milk when possible while their infants are in neonatal care, as this may offer the best chance for healthy brain development.”
The Jennifer Brown Research Laboratory, established in 2004 at the University of Edinburgh as a collaboration with Theirworld, focuses on identifying women at risk of preterm birth, developing strategies to prevent early labor, and improving care for newborns in the critical hours and days after delivery.
Sarah Brown, chair of Theirworld, adds: “The research and discoveries coming from the Theirworld Edinburgh Birth Cohort are exceptional. This pioneering study provides clinicians and scientists with valuable insights that are expanding medical knowledge and improving outcomes for babies born prematurely. We are deeply grateful to the families who contribute their time and information to help give other premature babies a better start in life.”
About this breastfeeding and neurodevelopment research news
Author: Press Office
Source: University of Edinburgh
Contact: Press Office – University of Edinburgh
Image: The image is in the public domain
Original Research: Open access. “Breast Milk Exposure is Associated With Cortical Maturation in Preterm Infants” by Gemma Sullivan et al., Annals of Neurology.
Abstract
Breast Milk Exposure is Associated With Cortical Maturation in Preterm Infants
Objective
Previous studies associate breast milk exposure with better neurocognitive outcomes after preterm birth, but the neural pathways linking breast milk to these outcomes remain unclear. This study tested whether higher versus lower exposure to breast milk in preterm infants produces cortical morphology at term-equivalent age that more closely resembles that of term-born infants.
Methods
The study included 135 preterm infants (<32 weeks’ gestation) and 77 term infants. Detailed feeding records were obtained from birth until hospital discharge, and brain magnetic resonance imaging (MRI) was performed at term-equivalent age. Researchers compared cortical measures—volume, thickness, surface area, gyrification index, sulcal depth and curvature—and diffusion parameters, including fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), axial diffusivity (AD), neurite density index (NDI) and orientation dispersion index (ODI). Preterm infants were grouped by breast milk exposure: exclusive breast milk for less than 75% of inpatient days versus exclusive breast milk for 75% or more of inpatient days, and compared with term-born controls. The team also examined dose–response relationships using breast milk exposure quartiles weighted by propensity scores.
Results
Among preterm infants, higher breast milk exposure was linked to cortical measures that indicated more advanced maturation. Specifically, high exposure was associated with reduced cortical gray matter volume and thickness differences relative to lower exposure, and with altered diffusion measures (reduced RD and increased FA) after adjusting for age at MRI—changes that resembled the cortical phenotype seen in term-born infants. Dose–response analysis using exposure quartiles, adjusted for age at birth and MRI and weighted by propensity scores, showed associations between greater breast milk exposure and cortical volume, FA and RD, supporting a graded effect.
Interpretation
High exposure to breast milk following preterm birth is associated with a cortical imaging profile at term-equivalent age that more closely mirrors the brain morphology of term-born infants. The findings appear to be dose-dependent, suggesting that greater volumes of breast milk during neonatal care may support cortical maturation in preterm infants.