<unk>  interacts with the LHCG receptor of the ovary and promotes the maintenance of the corpus luteum for the maternal recognition of pregnancy at the beginning of pregnancy. This allows the corpus luteum to secrete the hormone progesterone during the first trimester. Progesterone enriches the uterus with a thick lining of blood vessels and capillaries so that it can sustain the growing fetus. It has been hypothesized that<unk>  may be a placental link for the development of local maternal immunotolerance. For example,<unk> -treated endometrial cells induce an increase in T cell apoptosis (dissolution of T cells). These results suggest that<unk>  may be a link in the development of peritrophoblastic immune tolerance, and may facilitate the trophoblast invasion, which is known to expedite fetal development in the endometrium. It has also been suggested that<unk>  levels are linked to the severity of morning sickness or Hyperemesis gravidarum in pregnant women. Because of its similarity to LH,<unk>  can also be used clinically to induce ovulation in the ovaries as well as testosterone production in the testes. As the most abundant biological source is in women who are presently pregnant, some organizations collect urine from pregnant women to extract<unk>  for use in fertility treatment.<unk>  also plays a role in cellular differentiation/proliferation and may activate apoptosis.
Human chorionic gonadotropin
Gonadotropin
Progonadotropin
Menotropin
Estradiol
Estradiol 
Prolene
Sex hormone