The effect of gestational age at delivery on lactation outcomes in pump-dependent mothers of critically ill infants - Research Abstract Mother own milk (MOM) provides personalized risk reduction for neonatal intensive care unit (NICU) infants, but little is known about insufficient MOM in 84% of NICU mothers with non-very low birthweight infants, leaving a major research gap that disproportionately impacts Black NICU mother-infant dyads. Insufficient MOM volume has its origins in late pregnancy and postpartum days 1-14. The goal of this research is to determine the effect of GA on lactation outcomes among pump-dependent mothers of critically ill infants admitted to the NICU. A major lack of knowledge exists about the effect of mammary gland maturation on MOM volume, secretory activation (SA), and if/how it is mediated by MOM removal (e.g., breast pump use) during the critical window (postpartum days 1-14) of transition from secretory differentiation (epithelial cell preparation) to SA (onset of copious MOM volume) and autocrine control of lactation (permanence of SA) to ensure continued production of adequate MOM volume. To fill this gap, this revised mentored patient-oriented research career development award (K23) proposed study will follow 188 racially and economically diverse mothers of infants admitted to the NICU for postpartum days 1-14 and assigned to 1 of 4 groups based on the infant's GA at delivery. Aim 1 will compare measures of MOM volume between the GA groups over postpartum days 1-14. Aim 2 will compare measures of onset and permanence of SA using MOM biomarkers between the GA groups. Aim 3 is exploratory to gain evidence to characterize the relationship between biomarkers and MOM volume for the 4 GA groups. Understanding of these mechanisms and the impact of GA is critical to translate findings into early identification and personalized interventions for this vulnerable population. To this end, I have assembled an interdisciplinary team of senior scientists with complementary expertise in nutritional support for critically ill infants, clinical and translational research, biostatistics, and lactation biology who will provide mentorship to achieve the proposed training goals and facilitate my transition to an independent research career. Essential primary training goals include: 1) Advance understanding of the biology of lactation, maternal, and infant factors; 2) Develop and apply knowledge of the application of clinical and experimental designs, data acquisition, data analysis, and interpretation of findings; and 3) Develop leadership, research management, academic faculty, and grant writing skills essential for a productive research faculty member. University of Florida (UF), Shands Children's Hospital, and UF Diary Science are ideal environments to provide unparalleled resources to support and extend the PI's emerging translational clinical research to become a productive faculty member and independent researcher in patient-oriented research. The revised research plan is directly responsive to the reviewer comments and to the National Institute of Nursing Research's priorities focused on research using multilevel approaches bridging biology to society reducing risk, improving health, and advancing health equity, as well as aligns with NIH initiatives to prioritize human milk research.