Insufficient milk supply (IMS) is the most common reason for early weaning by breastfeeding women in the United States and worldwide. IMS is a major reason why the Surgeon General's goals for 1990 related to breastfeeding are not being met. The specific goals of this project are to: 1)Identify the defining characteristics of early IMS as a nursing diagnosis for mothers of term infants, 2)Prevent early, unintended weaning of infants by evaluating selected interventions designed to alleviate early IMS, and 3)Develop a prevention model which proposes the relationships among the etiology, defining characteristics and nursing intervention strategies of IMS. The project is proposed in three sequential phases: Phase I: An observational phase to define characteristics of early IMS in mothers of healthy term infants. Phase II: A randomized field trial to test nursing interventions designed to prevent early IMS from proceeding to late IMS or weaning in mothers of healthy term infants. Phase III: A causal modeling and theory building phase to explore the prevention of early IMS and to link practice level theory with middle range theories of nursing. The long term objective is to reduce the incidence of early weaning of breastfeeding infants through prevention of IMS.