In this first case, the main reason for a woman to no longer have any eggs available is a situation known as early menopause. It appears before the normal age and involves the menopause arriving between 15 and 20 years early. That is, a woman can start the menopause when she is still young and if she has not yet had any children she will now not be able to have them without resorting to a donation from a fertile woman.
Thanks to epidemiological studies, it is known that approximately 5% of women develop this pathology, a greater number than most people who are not familiar with this problem would imagine.
On other occasions, the causes are medical, like the cases of those women who have had to have their ovaries removed because of a tumour, for example. Once re-stabilised, these women would not be able to have their own children if it were not for the donation of eggs from other women.