Gonadotropin (also designated choriogonadotropin) is a hormone produced by the placenta in the first trimester of pregnancy and exists as a heterodimer formed from a common α chain and a unique β chain. The unique β chain confers biological specificity to thyrotropin, Lutropin, follitropin and gonadotropin. The secreted α subunit maps to human chromosome 6 and the β subunit maps to human chromosome 19. Gonadotropin stimulates the ovaries to produce and maintain normal levels of the steroids essential for maintaining pregnancy, including estrogen and progesterone.
