Acute Prolactin and Oxytocin Responses and Milk Yield to Infant Suckling and Artificial Methods of Expression in Lactating Women

Abstract

Breast-feeding is today the major form of infant nutrition in the immediate postpartum period. Despite this, recent trends in modern life-styles have raised obstacles to successful lactation. These include infant illness and maternal responsibilities outside the home, both requiring separation from the mother. While the hormonal dynamics of infant suckling are understood, little is known about the effects of artificial methods of milk expression. A variety of breast pumps exist in the current US market which vary considerably in price and effectiveness. To understand better the ability of these pumps to assist women in the maintenance of lactation, the current study was undertaken to evaluate their effects on milk yield and prolactin and oxytocin release when compared to natural infant suckling. Twenty-three women who were exclusively breast-feeding their infants were randomly assigned to serially use several pumping methods, as well as infant suckling, with blood being taken at 10-minute intervals to determine the hormonal responses. The results reveal variability in the prolactin responses to the artificial pumping methods, with the greatest responses found with an electric pulsatile pump; these responses compare favorably with those of natural infant suckling. Other methods were less successful in causing prolactin elevations. No differences were seen among the methods in the oxytocin response. The results of this study demonstrate striking differences in the ability of breast-pumping methods to produce an acute and sustained prolactin rise in breast-feeding mothers. The large discrepancies found suggest the need for further studies in to enable women and health care providers to choose the most appropriate method for milk expression.(ABSTRACT TRUNCATED AT 250 WORDS)