Which hormone is primarily responsible for the development of the corpus luteum in pregnancy?

The hormone primarily responsible for the development of the corpus luteum in pregnancy is human chorionic gonadotropin (hCG). After fertilization and implantation of the embryo, hCG is secreted by the developing placenta. This hormone plays a crucial role in maintaining the corpus luteum, which is vital for the production of progesterone in early pregnancy. The corpus luteum produces progesterone to support the uterine lining and maintain the pregnancy until the placenta is fully developed and can take over hormone production.

In the early stages of pregnancy, the presence of hCG is what signals the corpus luteum to continue functioning instead of degenerating. This is essential because progesterone is critical for preventing uterine contractions and ensuring a stable environment for the developing embryo. As the pregnancy progresses, the placenta eventually takes over the role of hormone production, but hCG is key to the initial maintenance of the corpus luteum and the hormonal support needed during the early stages of pregnancy.