Medical Student University of Washington School of Medicine Boise, Idaho, United States
Disclosure(s):
Amanda E. Lee: No financial relationships to disclose
Introduction/Rationale: Human milk contains bioactive immune mediators that shape early development. The postpartum period is a sensitive window; maternal anxiety, common globally, has been linked to altered inflammatory cytokine signaling. We conducted this study to assess associations between maternal inflammatory status and cytokine profiles in breast milk and maternal/infant serum, and to relate these measures to infant growth and behavior to inform strategies that support maternal and infant health.
Methods: We enrolled 20 breastfeeding dyads in rural Idaho/Washington. Participants self-collected breast milk at infant ages 6, 8, 12, 16, and 18 weeks; maternal and infant serum were collected at 8 and 16 weeks. Maternal anxiety was assessed with the State–Trait Anxiety Inventory (STAI), infant behavior with the Infant Behavior Questionnaire (IBQ), and infant growth was measured across the study. Select cytokines and growth factors were quantified in human milk, maternal serum, and infant serum by ELISA.
Results: Bioactive concentrations in milk varied among women and over time. Milk immune mediators showed greater between-dyad than within-dyad variability across lactation. In mixed-effects models, higher maternal STAI scores were associated with differences in cytokine profiles in milk and maternal serum. Exploratory lagged analyses indicated that immune mediator levels in prior milk samples related to subsequent infant growth trajectories and IBQ behavior scores.
Conclusion: In this rural cohort, maternal anxiety tracked with distinct milk and serum cytokine signatures, and these immune patterns prospectively related to infant growth and temperament—suggesting maternal mental health may shape early immune-nutritional signaling.
