Prevention of pregnancy occurs with the use of hormonal therapy found in prescribed oral medications named oral contraceptives or "the pill." These medications cause changes in the female's body to prevent conception. While they offer some of the most effective contraception available, they do not prevent sexually transmitted diseases from spreading. Birth control pills generally exist as progestin-only medications or as combinations of progestin and estrogen.
Ethinyl Estradiol and Levonorgestrel
Physicians and gynecologists prescribe the combination oral contraceptive of ethinyl estradiol and levonorgestrel to help prevent pregnancy, Drugs.com reports. They work by prevention of ovulation in women. These medications also work by causing changes in the uterine lining, making it increasingly difficult for sperm to reach the egg, stopping pregnancy from occurring.
Ethinyl Estradiol and Desogestrel
Ethinyl estradiol and desogestrel birth control pills combine progestin and estrogen. These medications include the female hormones that prevent monthly ovulation. The combination drug also alters the lining of the uterus, making it difficult for the sperm to reach the egg.
Norethindrone Acetate and Ethinyl Estradiol
The oral generic combination of norethindrone acetate and ethinyl estradiol prevents pregnancies from occurring. This form of birth control medication also functions by the prevention of ovulation in a woman, RxList.com reports. Changes in the uterine lining also occur to prevent pregnancy.
Progestin
Doctors typically prescribe progestin contraceptives in low doses. Drugs.com reports names for these kinds of oral contraceptives include POPs, which stands for progestin-only pills and minipills. Apart from retarding the growth of ovarian eggs, progestin thickens mucus in the cervix that decreases the likelihood of fertilization by sperm. Drugs.com states pregnancy still can happen. A further action of POPs, the prevention of attachment to the uterus of the egg after fertilization, can also help prevent pregnancy.
