This study examined the extent to which caregiving nurturance expressed in mothers' working models of infant feeding changed during the infant's first year and explored the influence of the infant's biologic development on this caregiving nurturance. Three methodologies were used: (1) 59 mothers of very-low-birth-weight (VLBW) infants with a history of lung disease and 53 mothers of healthy infants born at term were interviewed for dimensions of a working model of infant feeding; (2) the intensity of the infants' illness was assessed from a record of illness signs; and (3) the infants' weight compared to that of other infants was assessed in terms of weight-for-age. The results show that the caregiving nurturance of mothers' working models of infant feeding, on the whole, was not stable through the infant's first year. The results indicate that the mother's characteristics and personal experiences in feeding, environmental circumstances, and the meaning of infant behavior and characteristics are factors that potentially shape a mother's working model of infant feeding and are in need of exploration. (Contains 15 references.) (AP)