Donor human milk and structural brain development in very preterm infants

We investigated the impact of donor milk on structural brain development, relative to maternal milk feeding, in very preterm infants at term-equivalent age (TEA).

Very preterm infants ( ≤32 weeks' gestation) were enrolled in an observational study. Infants categorized as receiving primarily maternal milk (MOM), donor human milk (DHM), or preterm formula (PTF) based on cumulative feed volume underwent TEA brain magnetic resonance imaging for volumetric (coronal T2) and white matter (diffusion tensor imaging) development.

In this cohort of 152 infants (67 MOM, 44 DHM, 41 PTF), there were no significant differences in brain volumes between MOM and DHM. PTF demonstrated lower deep gray matter (β = -1.2, p = 0.024), brainstem (β = -0.4, p = 0.002) and total brain volumes (β = -17.2, p = 0.016) than MOM. Relative to MOM, DHM showed decreased white matter mean diffusivity in the pons (right: β = -0.04, p = 0.008; left: β = -0.06, p < 0.001); PTF had increased mean diffusivity in the corpus callosum (genu: β = 0.11, p = 0.007; splenium: β = 0.13, p = 0.007) and posterior limb of internal capsule (PLIC) (right: β = 0.06, p = 0.002; left: β = 0.06, p = 0.001) and decreased fractional anisotropy in the right PLIC (β = -0.02, p = 0.019).

Brain volumes and overall white matter development were not significantly different between DHM and MOM, while PTF-fed infants demonstrated lower total and regional brain volumes and greater white matter microstructural alterations.

Feeding very preterm infants maternal milk is associated with improved ex-utero third trimester brain development compared to formula, but the implications of donor milk for structural brain development remain unknown. We performed brain magnetic resonance imaging at term-equivalent age to compare structural brain development between very preterm infants primarily fed either maternal milk, donor milk, or preterm formula. Brain volumes and white matter microstructure in primarily donor milk-fed very preterm infants more closely resembled that of maternal-milk fed infants than did infants fed formula, suggesting donor milk offers a potential advantage for structural brain development when maternal milk is unavailable.