[Lactation regulation and the content of thyroid hormones in the milk of parturients and components of infant food formulas].

The content of folliculostimulating (FSH), luteinizing (LH), thyrotropic (TTH) hormones and prolactin was studied in the blood serum of pregnant women and puerperants; also the thyroxin (T4), triiodthyronin (T3), thyroxin-binding globulin (TBG) levels, and the thyroxin-binding capacity of proteins and free T4 index were determined in the blood serum and milk of puerperants during the first week of lactation. The blood serum FSH, LH, TTH and prolactin concentrations underwent definite changes connected with physiological reconstruction of the organism at these periods. The milk T4 and T3 levels showed a sharp elevation by the 6th day of lactation, this correlating with the changes in the blood serum. The milk TSH concentration was much lower than in the serum; the same regularity was revealed for the protein thyroxin-binding capacity. The free T4 index is exceedingly high in milk, being much greater than that in the blood serum. Of the 10 food products for supplementary feeding of children an insignificant amount of T4 was revealed in two only. No T4 was found in cow milk.