Birth Control Pills
There are two types of birth control pills: combination pills, which contain both estrogen and a progestin (a natural or synthetic progesterone), and “mini-pills,” which contain only progestin. The combination pill prevents ovulation, while the mini-pill reduces cervical mucus and causes it to thicken. This prevents the sperm from reaching the egg. Also, progestin’s keep the endometrium (uterine lining) from thickening. This prevents the fertilized egg from implanting in the uterus. The failure rate for the mini-pill is 1% to 3%; for the combination pill it is 1% to 2%.Combination oral contraceptives offer significant protection against ovarian cancer, endometrial cancer, iron-deficiency anemia, pelvic inflammatory disease (PID), and fibrocystic breast disease. Women who take combination pills have a lower risk of functional ovarian cysts. The decision about whether to take an oral contraceptive should be made only after consultation with a health professional. Smokers and women with certain medical conditions should not take the pill. These conditions include: a history of blood clots in the legs, eyes, or deep veins of the legs; heart attacks, strokes, or angina; cancer of the breast, vagina, cervix, or uterus; any undiagnosed, abnormal vaginal bleeding; liver tumors; or jaundice due to pregnancy or use of birth control pills.
Women with the following conditions should discuss with a health professional whether the benefits of the pill outweigh its risks for them:
- High blood pressure,
- Heart, kidney, or gallbladder disease
- A family history of heart attack or stroke
- Severe headaches or depression
- Elevated cholesterol or triglycerides
Serious side effects of the pill include blood clots that can lead to stroke, heart attack, pulmonary embolism, or death. A clot may, on rare occasions, occur in the blood vessel of the eye, causing impaired vision or even blindness. The pills may also cause high blood pressure that returns to normal after oral contraceptives are stopped. Minor side effects, which usually subside after a few months’ use, include: nausea, headaches, breast swelling, fluid retention, weight gain, irregular bleeding, and depression. Sometimes taking a pill with a lower dose of hormones can reduce these effects. The effectiveness of birth control pills may be reduced by a few other medications, including some antibiotics, barbiturates, and antifungal medications. On the other hand, birth control pills may prolong the effects of theophylline and caffeine. They also may prolong the effects of benzodiazepines such as Librium (chlordiazepoxide), Valium (diazepam), and Xanax (alprazolam). Because of the variety of these drug interactions, women should always tell their health professionals when they are taking birth control pills.