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What happens to the corpus luteum when pregnancy does not occur?
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menstruation
Cyclical changes during a woman's normal ovulatory menstrual cycle.
When pregnancy does not occur, the corpus luteum undergoes a process of degeneration known as luteolysis.1
Approximately 10 to 14 days after ovulation, the corpus luteum becomes inactive and involutes, meaning it shrinks in size. It eventually transforms into a whitish scar mass called a corpus albicans.23
As the corpus luteum degenerates, the production of estrogen and progesterone decreases significantly. This drop in hormone levels causes the constriction of uterine arteries, which interrupts the supply of oxygen and nutrients to the uterine lining (endometrium). Consequently, the endometrium is sloughed off, resulting in the vaginal bleeding characteristic of menstruation.13