What is the role of HCG in early pregnancy?

Human chorionic gonadotropin (hCG) plays a crucial role during early pregnancy. Here's an overview of its functions:

1. Production and Detection: hCG is primarily produced by the developing embryo and later by the placenta. Its levels rise rapidly in early pregnancy, doubling approximately every 48-72 hours. This makes hCG a key marker for detecting and confirming pregnancy through urine or blood tests.

2. Corpus Luteum Maintenance: hCG is vital in maintaining the corpus luteum, a small gland that forms in the ovary after ovulation. The corpus luteum produces progesterone, which is necessary for supporting the uterine lining and preventing menstruation during early pregnancy.

3. Progesterone Stimulation: hCG stimulates the corpus luteum to increase progesterone production. Progesterone plays a crucial role in preparing the uterus for implantation and maintaining the pregnancy. It relaxes the uterine muscles, thickens the uterine lining, and promotes blood flow to the uterus.

4. Placental Development: As pregnancy progresses and the placenta develops, it takes over the production of progesterone and other essential hormones. hCG continues to be produced by the placenta throughout the pregnancy, albeit at lower levels than in early pregnancy.

5. Immunomodulation: hCG is also involved in immunomodulation, which plays a role in preventing the mother's immune system from attacking the developing embryo or fetus.

hCG levels typically peak around 10-12 weeks of pregnancy and gradually decline afterward. However, some pregnant individuals might experience higher hCG levels if they are expecting multiples, have certain medical conditions, or are pregnant with a molar pregnancy.

Regular monitoring of hCG levels is often performed during early pregnancy to assess its progression and ensure the well-being of the mother and the developing embryo or fetus.