Which hormone is responsible for maintaining the corpus luteum during early pregnancy?

The hormone responsible for maintaining the corpus luteum during early pregnancy is human chorionic gonadotropin hormone (hCG). After fertilization and implantation, hCG is produced by the developing placenta. This hormone has a crucial role in signaling the corpus luteum to continue producing progesterone, which is essential for maintaining the uterine lining and supporting the early stages of pregnancy.

Without the action of hCG, the corpus luteum would regress, leading to a decrease in progesterone levels. This drop in progesterone would result in the shedding of the uterine lining, similar to what occurs during the menstrual cycle, thereby jeopardizing the pregnancy. The presence of hCG is thus a key factor in ensuring that the pregnancy can be sustained in its early phases.

In the context of the other hormones mentioned, while estrogen and progesterone are vital for various functions in pregnancy, they do not maintain the corpus luteum directly in the early stages. Testosterone is not involved in this process at all; its primary roles are related to male reproductive functions.