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 produced during pregnancy - first by the ovaries and later by the placenta. HCG hormone levels found in maternal plasma and urine increase dramatically during the first trimester and may contribute to causing nausea and vomiting often associated with pregnancy. 

• human placental lactogen (HPL)
  This hormone, produced by the placenta, ensures proper fetal development and plays a role in stimulating 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 produced by the placenta during pregnancy, to help maintain a healthy pregnancy.

• progesterone
  This hormone is produced 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.