(P27-032-25) Breast Milk Composition in the First Month for Health Dyads: Relationship to Infant Growth and Maternal Experience of Receiving Results

Objectives: Human milk is widely accepted as the optimal source of nutrition for infants, yet some infants do not gain weight as expected, leading to interventions that often result in early weaning or formula supplementation. This study aims to explore whether milk composition influences infant growth in the first 30 days of life, specifically investigating if insufficient weight gain in infants is associated with lower calorie intake from breast milk. Additionally, we examine maternal perspectives on receiving personalized milk macronutrient information and its impact on their breastfeeding experience.

Methods: Our study involved 75 participants, with milk samples and data collected on days 7, 14, 21 and 30 postpartum (pp). Milk macronutrient composition was analyzed using SpectraStar™ XT NIR Analyzer to determine correlation with infant weight gain. Furthermore, we conducted interviews with mothers who received their individual milk composition results to assess whether this information was perceived as beneficial and supportive during their breastfeeding journey. Two independent coders used thematic analysis and an iterative, line-by-line coding technique to identify major themes.

Results: Milk protein and lactose concentration changes between day 14 to 30 pp, but fat concentration and caloric content remain the same. We found no differences in milk macronutrients composition or total caloric content of mothers who reported concerns about their child’s weight gain upon enrollment compared with those who did not. Further analysis is ongoing to test if there is correlation between infant weight gain in the first 30 days pp and milk macronutrients composition. In addition, from the maternal interviews, our study identified four major themes related to maternal perspective on receiving their individual milk composition results.

Conclusions: Milk macronutrient composition varies over the first 30 days but does not appear to be a strong predictor of infant growth, although mothers are interested in receiving information about milk composition. This research will provide insights about the relationship between milk composition and infant growth and highlights the maternal experience and perceptions regarding personalized nutritional information, aiming to inform better support strategies for breastfeeding mothers.

Funding Sources: Mount Zion funds