What is the role of hCG during early pregnancy?

Human chorionic gonadotropin (hCG) plays a crucial role during early pregnancy primarily by maintaining the corpus luteum. The corpus luteum is a temporary endocrine structure that forms in the ovary after ovulation and produces progesterone, which is essential for maintaining the uterine lining and supporting the early stages of pregnancy. After conception, hCG is secreted by the developing embryo (specifically, the trophoblasts) and signals the corpus luteum to continue producing progesterone until the placenta is sufficiently developed to take over hormone production. This process is vital to ensure that the uterine environment remains suitable for the developing embryo and prevents menstruation.

The other options focus on roles that do not align with hCG's primary functions. For example, hCG does not initiate menstruation, trigger ovulation, or induce uterine contractions, which are controlled by other hormones or factors in the reproductive process.