Some aspects of milk synthesis and composition in relationship to the mother's ability to breast-feed her infant
Miller, R. A.
The problem of disordered lactation is a complex one and why some women should be unable to breast-feed their infants or only succeed in doing so for a limited period of time has never been fully understood. Many factors may account for inadequate lactation - factors concerning both mother and infant. Thus, where the mother is affected, her disability may arise from psychological or nutritional disturbances, endocrine dysfunction, or super-imposed systemic disorders. In the mammary gland itself, anatomical defect:, as well as disease, may sometimes be responsible for the mother's failure to breast - feed her infant. Although many cases of unsatisfactory lactation are probably due to these factors, the clinician is frequently satisfied in placing women in one or other category after a superficial examination and sometimes without completing a sufficient number of test -feeds. Thus, the aetiology and treatment of these cases is based merely on clinical impressions. Simple tests to determine the chemical composition of milk and its bacterial content are usually omitted, though it is hard to explain such neglect, because these lilies of investigation are frequently applied to cattle with sub-normal milk yields. Recently, however, the letting down of milk has been studied and thyroid and iodine therapy has been instituted it some cases to increase the milk yield, though the results so far have not been of outstanding practical value. The complete neglect of routine investigation of mothers with inadequate lactation is most unfortunate because a fuller understanding of such a disorder might result in mothers being judged more fairly and treated more efficiently by the physician. Moreover, a greater percentage of mothers woud be able to fulfil their ambition to breast-feed their infants, more mothers might enjoy better mental and physical health and more infants might pass unmolested through the hazards of the first year of life.In an attempt to find some investigation which would help the physician to assess a woman's ability to feed her infant, research has been carried out on certain tests which might give information as to the adequacy of lactation in women. These tests involve the estimation of the chloride content and electrical conductivity of milk and she protein and cholesterol in the blood, and have been made on samples of milk and blood taken from mothers who were breast -feeding their infants adequately and others who were breast-feeding them inadequately.The investigation on both chloride and electrical conductivity values of milk has been divided into four parts. The first part concerns the relationship of the test results to adequacy of lactation, the second is devoted to the effects of mammary disease upon various tests, including the milk chloride and conductivity tests, the third involves the assessment of the duration of lactation by means of the chloride and conductivity tests, while the fourth part is devoted to an assessment of the value of these tests for the detection of adulterated milk.Observations have been made on various constituents of' mothers' blood and a separate section has been devoted to each class of substance discussed. The first section consists of a review of the literature on the blood glucose of women and the relationship to the sugar content of milk and milk yield, the second is composed not only of a review, but also of investigations on blood protein in lactating women with varying milk yields, and the third section is devoted to a review of the literature correlating values of blood lipids with milk yield and to the correlation of a series of blood cholesterol values obtained for lactating women with the milk yield of these women.