List the four major hormones produced in early pregnancy. Describe what each one does.

California Institute of Technology| Nursing | California Institute of Technology

Human Chorionic Gonadotropin, Estrogen and Progesterone are the four main hormones that occur in pregnancy. Human Chorionic Gonadotropin is produced by the placenta. It helps maintain the lining in the uterus to prepare for the fertilized egg’s implantation. Estrogen increases blood flow in the uterus, breasts and stimulates ovarian growth. It also promotes fetal development. The progesterone hormone also increases the thickness of uterine tissue and promotes mammary gland growth in preparation for breast-feeding. Last but not least, Relaxin helps to increase joint flexibility which is necessary for a dilation of cervix in labor.