What hormone does the corpus luteum secrete to support pregnancy?

The corpus luteum plays a crucial role in the early stages of pregnancy by secreting progesterone. This hormone is essential for maintaining the uterine lining, providing a suitable environment for the implantation and growth of a fertilized egg. Progesterone helps to thicken the endometrium (the lining of the uterus), which is necessary to support the developing embryo.

In addition to supporting the uterine lining, progesterone also inhibits the contraction of the uterine muscles, reducing the risk of miscarriage during the early stages of gestation. It also plays a role in suppressing the immune response to prevent the mother's body from rejecting the embryo.

While estrogen is also produced by the corpus luteum and contributes to pregnancy maintenance, it is primarily progesterone that is vital for the initial stages. Testosterone and luteinizing hormone are involved in other processes within the reproductive system but do not play a direct role in supporting pregnancy initiated by the corpus luteum.