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. 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. This hormone is produced by
the ovaries and by the placenta durin