The Electrical Conductivity and Chloride Content of Women's Milk: Part 2: The Effect of Factors Relating to Lactation

Abstract

In Part I it was shown that the electrical conductivity of human milk is positively correlated with its chloride content. It was thought desirable to investigate in some detail the effect on both conductivity and chloride content of various factors connected with the time and mode of obtaining milk. Comparisons have been made between (1) fore-milk (milk taken just before a child is fed) and after-milk (milk taken just after a breast feed), (2) milk samples taken in the early morning, at mid-day, and in the evening, (3) milk samples taken at various stages of lactation, i.e., in the first, second, third, fourth, and fifth months of lactation, and (4) milk samples taken from right and left breasts respectively.Comparison of Fore-milk and After-milk From each of 62 women a specimen of milk was taken before and another taken after a breast feed, and the electrical conductivity and chloride content of each of 124 specimens was determined as soon as possible after taking the sample. Of the 62 women, some had an adequate milk supply, but in others there were signs that the lactation was inadequate. Their infants failed to gain weight and received less than 2 oz. of breast milk per lb. body weight each day. The average of the values for electrical conductivity of the 62 specimens of after-milk was 231-1x10-5+7 38x10-5 ohm-1 cm. -1, whilst the corresponding figure for fore-milk was219-4xl -5+ 8-29x10--5ohm-1cm.-1. The average chloride contents for the two series of milks were67-7+5 -12 mg.and 75 -2+6-13 mg.per 100 ml.respectively. It will be seen that the values are lower in the fore-milk than in the after-milk. Using the standard errors, we find that the differences are not significant. This method of comparison, however, does not allow for the fact that the fore-milk and after-milk observations have been made on the same series of women. We have, therefore, taken the differences between the values of the two samples of milk obtained from each woman and applied tests to ascertain whether the mean of these differences differs significantly from zero. The result is that the average of the differences of the conductivity values between fore-milk and after-milk does differ significantly from zero (t= 3 1), but for the chloride content the result is just significant (t=2-1). Hence, it may be concluded that the tendency for after-milk to have higher electrical conductivity and chloride values than fore-milk is a real one. Similar observations were made by Sisson and Denis (1921), Macy, Nims, Brown, and Hunscher (1931) and Ishii (1937), but their results were not statistically analysed.These authors were agreed that the values for after-milk could be either greater or smaller than those for fore-milk. Thus, when making investigations into either the electrical conductivity or chloride content of milk, all milk samples should be taken either before a breast-feed or after a breastfeed, unless the daily milk yield can be obtained for examination.Comparison of Morning, Mid-day, and Evening Milk Samples of milk from two series of ...

Lactation mastitis: Promising alternative indicators for early diagnosis

“…Similar to the pathological response in animals with LM[ 62 , 63 ], when a woman is diagnosed with LM, inflammatory factors, such as procalcitonin, IL-1, IL-6, IL-8, and TNF-α[ 36 ], cause disruption of the tight junctions between cells. Furthermore, as a result of both the decrease in available glucose, particularly during severe symptoms, and the damage or death of lactocytes due to inflammation, lactose synthesis decreases[ 20 ].…”