Effect of antenatal breast milk expression or postnatal dietary intervention on breastfeeding outcomes and human milk composition in women with excess weight: protocol for the Ready, Set, Nourish study, a randomized controlled trial

Background Human milk is recommended as the ideal source of nutrients intake for infants. It provides optimal nutrition and critical health benefits for both infants and mothers. However, women with excess weight are less likely to initiate and sustain breastfeeding. This study aims to assess how a prenatal and a postnatal intervention can improve breastfeeding outcomes, human milk composition, and infant growth in women with excess weight. Methods This three-arm randomized controlled trial will include 180 pregnant women with pre-pregnancy BMI ≥ 25 kg/m 2 recruited from central Arkansas. The participants will be randomized to a standard of care group receiving standardized lactation support ( N = 60); a prenatal intervention group receiving standardized lactation support + antenatal breast milk expression (ABME) between 37 weeks of gestation until birth ( N = 60); or a postnatal intervention group receiving standardized lactation support + dietary meal plan designed to align with the Dietary Guidelines for Americans from 2 weeks to 6 months postpartum ( N = 60). Study assessments will include repeated measures of maternal and infant anthropometrics, body composition, dietary intake, and archiving of biospecimens (blood, human milk, stool, and urine) during infancy and until 6 months postpartum. The primary outcomes are breastfeeding outcomes (initiation, duration, exclusivity) and human milk composition (macronutrients, energy, and bioactive components). Questionnaires will assess maternal demographics and socioeconomic status, breastfeeding self-efficacy, maternal depression, stress, and quality of life as well as infant feeding intention, and medical lactation history. Discussion This randomized control trial will generate novel evidence on the safety, feasibility, and effectiveness of ABME and provision of a healthy postnatal meal plan in a population at elevated risk for breastfeeding challenges. By evaluating clinical and nutritional strategies, this study will advance the understanding of how maternal behavior and physiology influence breastfeeding outcomes, human milk composition and early life programming of infant growth and development. Findings will also address critical gaps identified by the Dietary Guidelines Advisory Committee by guiding nutritional recommendations for women with excess weight. The results will inform future strategies targeting short and long-term maternal-infant health outcomes. Clinical trial registration https://clinicaltrials.gov/study/NCT00616395 , identifier NCT00616395.