Effects of Stress on Lactation

Abstract

With the benefits of human milk well recognized, it is an opportune time to focus attention on how to optimize lactation for the benefit of newborns. Availability of mother's milk is conceivable only if lactation is sustained. To achieve this, mothers must be willing first to breastfeed or pump to initiate lactation, and their lactation must be reasonably adequate if they are to maintain an interest in breastfeeding or pumping. Therefore, to safeguard lactation, one must understand not only the physiology of lactation but also how to initiate and maintain maternal interest in breastfeeding or pumping, particularly in times of stress. Lactation insufficiency frequently is blamed on stresses, such as those imposed by preterm delivery, infant medical condition, or maternal lifestyle. To address these issues, information pertinent to the effect of stress on lactation, the mechanisms by which stress may hamper lactation, and the factors that may alter maternal willingness to breastfeed or pump are reviewed. The various interventions developed to help mothers with lactation difficulties also are presented. Proper glandular development of the breast may be presumed for mothers of full-term infants 69 ; however, the extent to which the degree of mammary development after a preterm delivery affects lactation performance is unclear. Nevertheless, the initiation and maintenance of lactation require appropriate hormonal changes and maternal behavior. Figure 1 outlines three major interplays between mother and infant that need to develop to preserve lactation. First, the primary function of lactation is to provide nutrition to the newborn. As such, lactation performance is a function of supply and demand, that is, the greater the infant's needs, the greater the milk production and the more prolonged the lactation. Second, lactation is affected by maternal interest in providing milk to infants. This can be reinforced positively or negatively depending on maternal perception of whether she meets her infant's nutritional needs. Third, maternal interest in initiating and maintaining breastfeeding or pumping also is a function of her relationship with her infant. A constructive interaction will influence positively her drive to provide milk for her child. A negative experience, on the other hand, quickly ends with the breakup of the nursing dyad and cessation of lactation.