What effect does the secretion of progesterone by the corpus luteum have?

The secretion of progesterone by the corpus luteum plays a crucial role in preparing the endometrium, or the lining of the uterus, for potential implantation of a fertilized egg. When progesterone levels rise, it causes the endometrial lining to thicken and become more vascularized, creating an optimal environment for implantation. This is essential for early pregnancy; without sufficient progesterone, the endometrium would not be adequately prepared, leading to failure of implantation.

The other choices address processes that are unrelated to the primary function of progesterone following ovulation. While progesterone does not stimulate ovulation—this process is triggered by a surge in luteinizing hormone—its main role post-ovulation is to facilitate the conditions necessary for embryo implantation. This differentiation is key in understanding the hormonal cycles in the female reproductive system and the specific actions prompted by progesterone.