Colostrum TGF-β-1 associates with the duration of breast-feeding

Background Several stressful environmental factors are associated with short-term breast-feeding. A high concentration of sodium in colostrum has predicted early failure. Aim of the study We studied the association of growth factors in colostrum and the length of breast-feeding (BF). Methods We measured concentrations of TGF-beta 1 and -beta 2; epidermal growth factor, total protein, and sodium and compared their concentrations in colostral samples from mothers who either breast-fed their infants exclusively less than 0.5 months (n = 109) or longer than 3.5 months (n = 119). Results In the short BF group more mothers smoked and were primiparous more frequently and had less often a university education. They also provided the colostral samples significantly later than did those with long BF. Geometric mean concentration for TGF-beta 1 was 1.9 times as high in the samples from short BF mothers as in those with long BF; sinificant difference remained in comparisons of samples taken equally long postpartum. Samples from the short BF group showed higher levels for sodium, TGF-beta 2 and total protein, whereas concentrations of epidermal growth factor were similar between groups. Conclusions We thus infer that concentrations of factors in breast milk with an effect on the development and involution of the mammary gland, like TGF-beta 1 in milk, may be one of many biological factors having an impact on the successful initiation of breast-feeding.