Pregnancy

The endocrine glands and pregnancy

hCG

•First secreted by trophoblast cells before implantation and secreted later by the placenta

•hCG – binds to LH receptors on the luteal cells, preventing degeneration of the corpus luteum

•Thus maintains estrogen and progesterone

•This increased estrogen stimulates the secretion of prostagandins from the endometruim of the uterus, which then increases vascular permeability and swelling of the endometruim

Why is hCG so important?

•What happens when progesterone levels fall

–Corpus luteum degererates

–Necrosis of the endometrium

–Menstruation

•All prevented by secretion of hCG by the blastocyst