Cloning and Expression of Biologically Active Human Fertility Hormones

The three human gonadotropins, choriogonadotropin (hCG), luteinizing hormone (hLH) and follicle stimulating hormone (hFSH), are glycoproteins playing a major role in ovulation, spermatogenesis and conception. hCG is secreted by the developing placenta during the first trimester of pregnancy. Both hLH and hFSH are secreted by the pituitary and together play a central role in regulating menstrual cycle and ovulation.