Q: I've been on and off of some form of birth control for the past 20 years, but I keep hearing conflicting news on the dangers and benefits. I am a single woman and use it to prevent pregnancy. What should I believe?

Contraceptive techniques have been an integral part of women's health care for many years. Over time, contraceptives and women's attitudes regarding them have changed.  Many women now choose to delay or completely forego childbearing, and the prolonged prevention of pregnancy has become a very significant issue.

Oral contraceptives are the most commonly used method of birth control.  Since their introduction about 50 years ago, the formulations have changed significantly, using less hormones.  In the past, the Food and Drug Administration (FDA) set upper limits for a user's age.  In 1989 all upper age limits in healthy non-smokers were removed. These are very effective drugs and have more than a 90 percent success rate in the first year of use.  Failures are usually related to user non-compliance, such as forgetting to take the pills. 

They also have considerable non-contraceptive benefits.  These include menstrual cycle regulation, treatment of heavy or painful menses, menstrual migraines, PMS, endometriosis, pelvic pain, acne, and excessive hair growth.  They can also be used to manipulate menstrual periods for lifestyle considerations, such as a planned vacation.

Oral contraceptives significantly decrease a woman's risk of developing endometrial or ovarian cancer.  This protective effect seems to increase with duration of use and persists after discontinuation of therapy.  Studies have shown that the current or former use of oral contraceptives does not appear to increase the risk for developing breast cancer.

This data may not apply to women with breast cancer genetic mutations.

Risks that are associated with the pill include an increased risk of heart attack, stroke, and blood clots. The risk is greater in smokers who take the pill.  It should be noted that the incidence of these conditions is also increased with pregnancy.  Cervical cancer and oral contraceptive use has been linked, however this may be due to the association of cervical cancer with Human Papilloma Virus (HPV).  Further studies are ongoing.

Contraindications to the use of oral contraceptives include previous blood clots, stroke, heart attack, estrogen-dependent tumor, active liver disease, hypertriglyceridemia, undiagnosed uterine bleeding, inherited states of increased coagulation, migraine headaches with aura, diabetes or hypertension with vascular involvement.  Also anyone over 35 with migraines or who smokes should avoid them.

Another form of long-term contraception is intrauterine contraceptives (IUCs).  There are two products available in the U.S. The Mirena system releases an intrauterine dose of progestin and is effective for five years.  The Paragard is a copper-containing system, which is good for 10 years.  Both are approved for women of all ages.  They are both highly effective, and require an office procedure for insertion.  The Mirena is also approved for treatment of excessive menstruation. 

Depo Provera and Implanon are the two available long-acting progestin contraceptives.  Depo Provera is an injection given every 12 weeks.  It carries an FDA warning that bone loss may occur after long-term use.  It is associated with the cessation of menses in most users.  The Implanon system consists of a single implantable rod, which is placed in the user's arm under local anesthesia in the clinic.  It must be replaced every three years.  Its biggest side effect is irregular bleeding.

There are multiple options that are available to women for prolonged and consistent contraception. The choice an individual makes depends on her preferences, risk factors and history and should be thoroughly discussed with her health care provider.

Robert S. Goldfarb, M.D., is an obstetrician and gynecologist at Henry Ford West Bloomfield Hospital in West Bloomfield, Michigan.  His clinical interests include general obstetrics, menopause and minimally invasive surgery.  He is also an assistant clinical professor of obstetrics and gynecology at Wayne State University in Detroit.