Background: In the United States, African American infants experience the highest mortality, and their mothers report the lowest breastfeeding rates. Science reports decreased infant mortality among breastfed infants and suggests that milk immune component (MIC) levels are associated with maternal stressors. Little is known about these relationships among African Americans; therefore the aim was to explore the relationships of African American mothers' stressors and MICs 1-14 days postdelivery.
Materials and methods: Mothers meeting eligibility requirements were approached for consent 48-72 hours postdelivery of a healthy term infant and given instructions to collect milk (Days 3, 9, and 14) and saliva (Day 9), as well as complete three Perceived Stress Scale questionnaires (Days 3, 9, and 14) and a survey of pregnancy stressors experiences. Pearson correlations and linear regressions were performed to assess the relationships of maternal stressors with MICs.
Results: There was at least one statistically significant correlation of a maternal stressor with nine of the 10 MICs (effect sizes ranging from r = 0.22 to 0.38) on Days 3 and 9. Of all MICs, epidermal growth factor had the most associations with maternal stress indicators. No mediational relationship of cortisol with MICs was observed.
Conclusions: Many of the MIC changes observed could potentially impact the health of term and preterm infants. Further research is warranted.