Thyrotropin hormone is a glycoprotein with a molecular weight of 28,000 Daltons which is secreted by anterior lobe of pituitary cells. This hormone has been formed by two chains, namely alpha and beta. Despite beta chain which is exclusive and specific for immunologic features of TSH molecule, alpha chain is similar to those of LH, FSH and HCG hormones. Secretion of TSH is stimulated by Thyrotropin-Releasing Hormone (TRH) which is secreted by hypothalamus. Increased levels of T4, FT3 in a negative mechanism results in secretion. According to international statistics, one baby out of every 3,000 to 4,000 babies suffers... More...