Evaluating Breast Pumping Protocol Efficiency and Elucidating Molecular and Cellular Mechanisms of Enhanced Milk Production - Human milk provides optimal nutrition for infants; however, only 25% of U.S. mothers achieve the breastfeeding targets recommended by the Centers for Disease Control, which emphasize six months of exclusive breastfeeding. Suboptimal breastfeeding practices have profound public health consequences, costing the U.S. an estimated $13 billion annually and resulting in the preventable deaths of over 900 infants. These outcomes are often attributed to early breastfeeding cessation or the inability to sustain exclusive breastfeeding, with low milk production being the most frequently cited reason. Additional challenges include concerns about milk composition and quality. Insufficient milk production negatively impacts infant growth, maternal mental health, and maternal experiences overall, yet the physiological mechanisms underlying these issues remain poorly understood, and treatment options are very limited. The proposed research seeks to address these critical issues by employing a randomized clinical trial design alongside molecular insights into mammary gland biology. This study will include three intervention arms: (1) instructions to pump after breastfeeding session 6-8 times per day, (2) instructions to pump following breastfeeding sessions only 3-4 times per day, and (3) no specific instructions to add pumping sessions. The trial will span 14 days, during which maternal milk production, mammary gland transcriptomic changes, and milk composition alterations will be tracked and analyzed. Participants will provide milk and blood samples, detailed records of expressed milk volume, and daily questionnaires tracking breastfeeding and pumping schedules. This research combines a robust randomized trial design with innovative molecular analyses, such as RNA-seq of milk-derived transcripts profiling, to elucidate changes in mammary gland function and secretory processes resulting from these clinical interventions. This interdisciplinary strategy directly aligns with the mission of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) to advance knowledge of maternal and infant health. By integrating clinical and molecular approaches, this project seeks to generate evidence-based strategies to improve breastfeeding outcomes, providing crucial insights into both the physiological and clinical factors underlying low milk production and lactation challenges.