Luteal phase
Appearance
The luteal phase is the latter phase of the estrous cycle in animals, and the menstrual cycle in humans and great apes. It begins with the formation of the corpus luteum and ends in either pregnancy or luteolysis. The main hormone controlling this stage is progesterone. [1]
Luteal phase defect
Luteal phase defect (LPD) is believed to interfere with the implantation of embryos [2]. The Lactational Amenorrhea Method of birth control works primarily by preventing ovulation, but is also known to cause LPD.