A Woman's Journey : Pregnancy : Women's health : Your Changing Body
Hormones During Pregnancy
What is the role of hormones during pregnancy?
Many hormone levels are affected in the body during pregnancy, with several hormones playing major roles during pregnancy. These include:
Human chorionic gonadotropin hormone (hCG). This hormone is only made during pregnancy — almost exclusively in the placenta. HCG hormone levels found in maternal blood and urine increase dramatically during the first trimester. They may contribute to causing nausea and vomiting often associated with pregnancy.
Human placental lactogen (hPL). This hormone, also known as human chorionic somatomammotropin, is made by the placenta. It provides nutrition for the fetus and stimulates milk glands in the breasts in anticipation of breastfeeding.
Estrogen. This group of hormones is responsible for the development of the female sexual characteristics. Normally formed in the ovaries, estrogen is also made by the placenta during pregnancy to help maintain a healthy pregnancy.
Progesterone. This hormone is made by the ovaries and by the placenta during pregnancy. Progesterone stimulates the thickening of the uterine lining in anticipation of implantation of a fertilized egg.