Similarly to LH, FSH and TSH, human chorionic gonadotropin (hCG) is a member of the glycoprotein family and consists of 2 subunits (α‐ and β‐chains) which are associated to the intact hormone. The α‐chains in all four of these glycoprotein hormones are virtually identical, whereas the β‐chains have greatly differing structures and are responsible for the respective specific hormonal functions.. HCG stimulates the corpus luteum which produces progesterone in the first week of pregnancy. Progesterone: Prevents menses. It supports pregnancy. The alpha subunit is the same for all the glycoprotein Like LH, FSH, and TSH while the beta unit is unique for HCG. Therefore the beta(β) subunit is specific for HCG.. Human chorionic gonadotropin (hCG) conversion to mIU/mL, IU/L. Online conversion calculator for many types of measurement units in laboratory and medicine Human chorionic gonadotropin (hCG) ,.