And those who have taken the pill for 10 or more years have only one-third the risk. The pill also protects against cancer of the endometrium, the lining of the uterus, probably because there is less buildup of the lining while the pill is being taken. But taking the pill, which causes a thickening of the cervical mucus, seems to make it more difficult for sexually transmitted organisms to invade the pelvic organs. If undetected, it can be a life-threatening condition. And fibroids, benign growths in the uterus, can sometimes necessitate a hysterectomy.
Ovulation stimulates the growth of the endometrium.
Because the pill blocks ovulation, it also reduces the likelihood of this disorder. Women going through perimenopause and menopause often rely on the pill for these estrogen-induced benefits, among others. Many researchers believe that the estrogen in oral contraceptives may also help protect bone density and thus help prevent osteoporosis. But there's no concrete evidence. Despite these preventive health benefits, only about half of U.S. health insurance companies cover monthly birth control pill prescription costs.