During pregnancy, which hormone is primarily responsible for maintaining the corpus luteum?

The hormone that is primarily responsible for maintaining the corpus luteum during pregnancy is human chorionic gonadotropin (hCG). After fertilization and implantation, the developing placenta produces hCG, which signals the corpus luteum to continue producing progesterone. This is crucial because progesterone plays a significant role in maintaining the uterine lining, supporting the early stages of pregnancy, and preventing menstruation.

While estrogen and progesterone are essential for various aspects of pregnancy, it is hCG that directly maintains the corpus luteum during the initial phase following conception. Its role is vital in the early weeks of pregnancy until the placenta is sufficiently developed to take over hormone production. Oxytocin, on the other hand, is more associated with triggering labor and nursing rather than with early pregnancy maintenance. Therefore, hCG's specific function in sustaining the corpus luteum distinguishes it as the key hormone in this context.