"Luteal" refers to the phase in a woman's menstrual cycle when the lining of the uterus thickens in preparation for a possible pregnancy. Full definition
Low progesterone is one of the main causes of Luteal Phase Defect and Estrogen Dominance. (nicolejardim.com)
I am not sure of root cause my progesterone is slightly low during luteal phase or if low serotonin cause this issue or low blood sugar at night. (everywomanover29.com)
Cell death induced by serum deprivation in luteal cells involves the intrinsic pathway of apoptosis. (abcam.com)