Every woman is born with a fixed number of eggs. The number decreases with age, and the egg reserve becomes smaller. In addition, the quality of the eggs decreases as the woman gets older. In addition, with increasing age, other risk factors can affect fertility: Diseases, stress, being overweight or underweight, mental stress, excessive exercise or alcohol or nicotine consumption, and a diet low in vitamins. Nevertheless, women over 40 have a chance of becoming pregnant.