When is the corpus luteum formed?

The formation of the corpus luteum occurs following ovulation, which is when an ovary releases a mature egg. This process typically takes place in the menstrual cycle, specifically during the luteal phase. After the egg is released, the empty follicle transforms into the corpus luteum, which produces hormones such as progesterone. This hormone is vital for preparing the endometrium for a potential implantation of a fertilized egg.

While it is true that the corpus luteum forms during every menstrual cycle in response to ovulation, the correct and more precise context is that it specifically forms after ovulation. Therefore, while the corpus luteum does indeed form in each cycle, its formation is directly linked to the occurrence of ovulation. The other options do not accurately align with the biological process of corpus luteum formation. For instance, it does not form during menstruation, nor is it exclusive to pregnancy, as its main role is related to the menstrual cycle.