Associations among Human Milk Polyunsaturated Fatty Acids and Infant Sleep Patterns: A Cross-Sectional Study

Background: Infant sleep is critical for cognitive, emotional, and long-term health outcomes. Although diet–sleep relationships are established, limited research has explored how polyunsaturated fatty acids (PUFAs) in human milk (HM) relate to infant sleep. Objectives: This study aims to examine associations between PUFAs in HM and sleep patterns in 2-mo-old infants exclusively fed with HM. Methods: This cross-sectional secondary analysis used data from a lactation cookie trial involving 131 parents of healthy, term infants. Participants provided a fasting HM sample and completed sociodemographic and Brief Infant Sleep Questionnaire surveys. Multivariate linear models were adjusted for infant sex assigned at birth, weight-for-length z-scores, maternal prepregnancy body mass index, and daily feedings. Results: Participants self-identified as 81.7% White, 13.3% Hispanic, with 25.9% reporting an annual income