Placenta Hormones: Roles in Pregnancy - Progesterone, Estrogen, hCG

Progesterone

* Maintains the uterine lining during pregnancy

* Prevents the uterus from contracting

* Relaxes the muscles of the cervix and vagina

* Increases blood flow to the uterus and placenta

Estrogen

* Thickens the uterine lining

* Stimulates the growth of the breasts and uterus

* Increases blood flow to the uterus and placenta

Human chorionic gonadotropin (hCG)

* Stimulates the ovaries to produce progesterone

* Maintains the corpus luteum, a gland that produces progesterone

* Prevents the menstrual cycle from occurring

Placental lactogen

* Stimulates the growth and development of the breasts

* Increases the production of milk

* Regulates the metabolism of glucose and amino acids

Relaxin

* Relaxes the muscles of the uterus, cervix, and vagina

* Helps the baby to move down the birth canal during labor