What causes infertility in women?

The most common cause of female infertility is ovulation disorders. Problems with ovulation affect about 25% of all infertility situations. Other causes of female infertility include blocked fallopian tubes, which can happen when a woman has had pelvic inflammatory disease or endometriosis; Congenital anomalies (birth defects) involving the structure of the uterus, and uterine fibroids which are associated with repeated miscarriages; and aging, since the ability for ovaries to produce eggs tends to decline with age, especially after the age of 35.