What is the role of the hormone human chorionic gonadotropin (hCG) during early pregnancy?

The hormone human chorionic gonadotropin (hCG) plays a crucial role in early pregnancy by helping to maintain the corpus luteum. After fertilization, the developing embryo produces hCG, which signals the corpus luteum to continue producing progesterone. This hormone is vital for sustaining the endometrial lining and providing the necessary environment for the embryo to implant and grow. Without hCG, the corpus luteum would degenerate, leading to a drop in progesterone levels and resulting in the potential loss of the pregnancy.

Additionally, hCG is often the hormone detected by pregnancy tests, as its presence indicates that an embryo is developing. The maintenance of the corpus luteum by hCG is essential during the first trimester, until the placenta takes over the production of hormones necessary for continuing pregnancy. This crucial support allows for the proper conditions for the growth of the early embryo, thus underscoring the importance of hCG in early gestation.