Female Contraception

Description

Alternative Names

Oral Contraception

Oral contraceptives (OCs) are available only by prescription and come in either a combination of estrogen and progestin or progestin alone. Many brands of each form are available. Although both are equally effective with typical use, the combined pill is more effective with perfect use and most women choose this form.

Some women, however, experience severe headaches or high blood pressure from the estrogen in the combined pill and must take the progestin-only pill. Not all combined pills or progestin-only pills are alike, and brands differ in the amount of estrogen or progestin they contain. Many OC combined brands now use lower estrogen doses than previous brands and are proving to be safe and effective while providing a better quality of life than earlier OCs.

For all OC users, a check-up at least once a year is essential. It is also important for women to have their blood pressure checked three months after beginning the pill. Former pill users who want to bear children usually regain fertility in three to six months, but they may regain it even sooner.

Click the icon to see an image of a blood clot.

Combination Estrogen/Progestin Contraceptive Pills

Oral contraceptives that contain both estrogen and progestin are the more common type. At least 10 million American women and 100 million women worldwide use the combination OCs. When they were first marketed in the early 1960s, OCs contained as much five times the amount of estrogen and up to 10 times the amount of progestins currently used. After reports of severe complications (stroke, heart attack, and pulmonary embolisms) in young women, the hormone amounts were significantly reduced.

Many different progestins are used. The estrogen compound used in most oral contraceptives is ethinylestradiol, and current dose levels range from 20 to 50 micrograms. Fifty micrograms of estradiol are considered in this report to be high dose, 30 to 35 micrograms are considered to be low dose, and 20 microgram are very low-dose. (It should be noted that the high doses found in current OCs are still much lower than in previous forms.) Expert groups recommend using the lowest possible progestin and estrogen doses (no higher than 50 micrograms).

Brands include the following and their effects vary by estradiol dose level and by the progestin used:

• Desogestrel/estradiol: Desogen and Ortho-Cept are low-dose and Mircette is very low dose. Mircette has been associated with reduced menstrual cramps. According to major analyses, however, low-dose desogestrel poses a higher risk for blood clots than levonorgestrel.
• Drospirenone/estradiol: Yasmin is a low-dose contraceptive. Drospirenone has effects similar to natural progesterone. It is derived from a compound found in some diuretics (water pills) and has no male hormone effects. At this time, it may have fewer side effects than older OCs, including weight gain and emotional swings. It also reduces PMS symptoms and severe cramps and may reduce acne.
• Ethynodiol diacetate/estradiol: Demulen, Zovia are high-dose.
• Gestodene/estradiol: Minesse is a low-dose oral contraceptive approved in Europe. Gestodene is associated with a higher risk for blood clots than levonorgestrel.
• Levonorgestrel/estradiol: Levlen, Levora, Nordette, Portia, Triphasil, Seasonale, and Tri-Norinyl are low-dose and Alesse, Aviane, Levlite, and Lessina are very low-dose forms.
• Norethindrone acetate/estradiol: Estrostep, Loestrin, and Microgestin are all available in low to very low dose.
• Norethindrone/estradiol: Brevicon, ModiCon, Necon, Norethin Nortrel, Ortho-Novum are low dose. Ovcon is available in low and high doses.
• Norethindrone/mestrano: Necon, Norinyl, and Ortho-Novum are high-dose.
• Norgestimate/estradiol: Mononessa, Ortho-Cyclen, Ortho Tri-Cyclen, Sprintec are low dose.
• Norgestrel/estradiol: Cryselle is low-dose and Ovral and Ogestrel are available in low-dose and high-dose forms.
• Some of these brands are also available with iron. Of interest are injections and skin patches that are now available that contain both estrogen and progestin. Their side effects are similar to the combination OCs. Investigative progestins such as nestorone are being investigated in implants, gels, vaginal rings, and patches. [See Box Other Methods for Administering Combination Hormones.]

Types of Regimens. Combination pills are sold in 21-day or 28-day packs:

• Each pill in the 21-day pack contains the necessary estrogen and progestin.
• The 28-day pack adds seven differently colored reminder pills; they are inactive and do not contain hormones, but help the user maintain her daily routine during seven days between active pill use.

OCs may be taken in cycles that include pills of the same or different strengths. These are categorized as monophasic (one-phase), biphasic (two-phase), or triphasic (three-phase).

• Monophasic regimen (e.g., Alesse, Brevicon, Demulen, Desogen, Genora, Levlen, Levlite, Loestrin, Lo/Ovral, ModiCon, Necon, Nordette, Norethin, Norinyl, Ortho-Cyclen, Ortho-Novum, Ovcon, Ovral, Yasmin, Zovia.) A 21-day pack uses tablets that are one strength and one color for 21 days. (A 28-day pack adds seven inactive tablets of a different color.)
• Biphasic regimen (e.g., Mircette, Necon, Nelova, Ortho-Novum). A 21-day pack consists of tablets of one strength and color taken for seven or 10 days, then a second tablet with a different strength and color for the next 11 or 14 days. (And a 28-day pack adds seven inactive tablets of a third color.)
• Triphasic regimen (e.g., Cyclessa, Estrostep-21, Ortho-Novum 7/7/7, Ortho Tri-Cyclen, Tri-Levlen, Tri-Norinyl, Triphasil, Trivora). This pack consists of tablets with three different colors and strengths. In the first phase, there are tablets of one color for five to seven days; for phase two, a second color and strength tablet is taken for five to seven days; and for phase three, a third color and strength tablet is taken for five to 10 days. The difference in duration of each phase depends on the brand. (And a 28-day pack includes a fourth color inactive tablet for the last seven days.)

In all cases, women continue to menstruate, but their periods are lighter, shorter, more regular, and less painful than in women who are not on the pill. It is not clear if the biphasic or triphasic regimens offer any advantage over the monophasic in controlling bleeding. The monophasic regimen is the most studied regimen, and a major analysis found no major differences in bleeding control between monophasic and biphasic systems. One analysis found better bleeding control with the triphasic than the biphasic, but this have been due to different progestins used in each regimen (levonorgestrel in the triphasic and norethindrone in the biphasic).

Some researchers are investigating continuous oral contraceptives, either by extending a monophasic regimen or by using specific agents (. e.g., Seasonale, which contains estrogen and levonorgestrel). This approach produces a period only about every three months. Continuous OCs have the potential for helping women with either heavy bleeding, painful periods, or both. Breakthrough bleeding is the most common side effect but decreases over time. This approach is not suitable for women who frequently miss taking their pills. Long-term effects of steady hormone use are not known, and continuous contraceptives are still in trials.

Taking the Pills. Typically, the user takes the first pill either on the Sunday after her period starts or during the first 24 hours of her period. (The first pill can be started at any time during the menstrual without affecting the bleeding patterns. Ovulation can occur that month, however.) The remaining pills are taken once a day, ideally at the same time of day, until the pack is used up. The user, if she has a 21-day pack, waits seven days before starting a new pack. If she is on the 28-day pack, she takes the seven inactive pills.

If a woman misses one or more pills, she should take the following precautions:

• Missing the first pill in a new cycle. Take a tablet as soon as she remembers and the next one at the usual time. Two tablets can be taken in one day. Use barrier contraception for seven days after the missed dose. [See Spermicidal and Barrier Contraception.]
• Missing a pill two days in a row. Take two pills as soon as she remembers and then two more the following day. Also use back-up barrier contraception until the next pill cycle.
• Missing more than two, she should discard the pack, use a back-up birth control method and begin a new cycle on the following Sunday, even if she has started bleeding. One study found that women who miss three pills will probably still not ovulate, but nevertheless, they should take all necessary the precautions to prevent pregnancy.

Progestin-Only Oral Contraceptives

Progestin-only pill brands including the following:

• Levonorgestrel (Plan B).
• Norethindrone (Micronor, Avgestin, Norlutin, Nor-QD). (This progestin is made from male hormones, so may cause more male side effects than others.)
• Norgestrel (Ovrette).

Progestin-only pills, which only contain progestins, are always sold in 28-day packs and all the pills are active. Progestin-only pills must be taken at precisely the same time each day to maintain top effectiveness. If a woman deviates from her pill schedule by even three hours, she should call her doctor about using back-up contraception for the next two days. Progestin-only pill users will experience even lighter periods than those taking combination pills; some may not have periods at all. These agents should not be used by premenopausal women in their 40s, since they pose a higher risk for adverse effects in this group.

Advantages of Oral Contraceptives

Oral contraceptives are the choice of between one-quarter and one-third of American women who use birth control, making them the most popular reversible contraceptives in the US. OCs are among the most effective contraceptives; failure rates are very low and are usually due to noncompliance. One study suggested that women who weigh more than their peers have a higher risk for failure. The reasons for this are unclear. The risk for these women is also still very low, however.

OCs also have the following advantages:

• More sexual freedom. OCs do not interfere with intercourse, and in fact, many women report that sex is more pleasurable because they no longer have to worry about pregnancy.
• Reduce menorrhagia (heavy bleeding) and, therefore, reduce the risk for anemia.
• Reduction in dysmenorrhea (severe pain). High-dose OCs have been especially helpful, but they carry risks. Specific newer low-dose OCs that contain certain progestins, such as Yasmin (with drospirenone) and Mircette (with desogestrel), may reduce menstrual pain.
• Possible reduction in premenstrual syndrome with specific OCs, notably Yasmin. This OC may reduce premenstrual depression, water retention, and appetite to a greater degree that other OCs. Some OCs, however, are associated with worse emotional changes. Monophasic OCs may have a more beneficial effect on mood than triphasic OCs. To confuse matters, OCs with high progestin/low estrogen levels may produce worse moods in women without premenstrual syndrome but may be helpful for women with PMS.
• Reduction in endometriosis.

Endometriosis is the condition in which the tissue that normally lines the uterus (endometrium) grows on other areas of the body causing pain and irregular bleeding.

• Reduction of ovarian cancer. OCs reduce the risk of ovarian cancer by 30% to 50% (even in women with genetic risk factors). Progestin appears to be the protective factor by suppressing ovulation. Protection occurs after five years of use and persists for 10 to 20 years after stopping. (One study indicated that taking birth control pills for only three to six months may confer long-term protection.) Some experts believe that women at particular risk for ovarian cancer might consider oral contraceptives with the highest progestin dose.
• Reduction of endometrial (uterine) cancer. Older OCs reduced the risk for endometrial cancer by half. More studies are needed on newer formulations, which have lower doses of estrogen, but it is generally believed that they, too, are protective.
• Possible protection against colon cancer. Duration of use does not seem to be associated with decreased risk, but protection appears stronger for women who have used oral contraceptives more recently.
• Acne improvement with low-dose OCs. (Some low-dose OCs, such as Ortho Tri-Cyclen, have been specifically approved for acne reduction, although most low-dose OCs reduce testosterone levels and so many may help reduce acne. Yasmin, for example, has properties that block male hormones, which are associated with acne. In one study, Yasmin use produced a 63.5% response.)
• Possible protection against bone loss with low-dose OCs in some cases. The effect of OCs on bone density is unclear and may depend on the specific formulas that make up an OC. An important Canadian study that followed a group of young women found that OCs resulted in lower bone density and higher risk for fractures, possibly because taking OCs at younger ages interferes with achieving peak bone mass. Some evidence suggests, however, that OCs may protect against bone loss in women during the perimenopausal period. In addition, specific progestins (such as norethindrone or norgestimate) may be bone protective. More research is needed.

Disadvantages and Complications of Oral Contraceptives

Common Side Effects. Estrogen and progesterone have different side effects and women on the combined pill may experience different effects from those on the progestin-only pill. Symptoms of serious problems include severe abdominal pain, chest pain, unusual headaches, visual disturbances, or severe pain or swelling in the legs. Of note, in spite of some concerns, combination OCs do not cause weight gain.

[For specific side effects of estrogen and progestin, See Box Hormones Used in Contraception.]

Serious Effects on Heart and Circulation. OCs posed some serious risks when they first were introduced and estrogen and progestin levels were high. Such complications include blood clots, heart attack, stroke, and pulmonary embolism.

Most of the current low-dose OCs have reduced the risk significantly, although a risk for one or more of these complications still exists in women with certain risk factors (e.g., genetic factors, smoking, severe diabetes, and high blood pressure). Even among high-risk young women the additional risk for heart attack and stroke is still low. For example, low-dose OCs add only 9 complications per 100,000 women who smoke and have high blood pressure (which is still lower than the risk of death from pregnancy itself). Newer formulations have also reduced these risks.

The following are some observations on these complications.

• Blood clots (thromboses). Oral contraceptive use increases the risk for blood clots, particularly in women with inherited clotting defects. (Unfortunately, tests for genetic abnormalities that increase the risk for blood clots are expensive and not routinely available.) The risk is highest in the first few months. The danger, however, is very slight, particularly in women with no other risk factors.
• Hypertension. High blood pressure that occurs after a woman begins taking OCs can usually be corrected by discontinuing the medication, and women who use OCs should not be unduly alarmed. Of some concern was a study suggesting that OCs may cause a small but persistent increase in diastolic blood pressure (the second number in a blood pressure reading), which in turn may increase the risk for heart disease years later.
• Stroke. Evidence has consistently reported a higher than normal risk for stroke in women taking OCs even if women have no other stroke risk factors. The current low-dose OCs have significantly reduced the danger. Women with high blood pressure, however, still face a higher risk for stroke, particularly in the presence of smoking and migraines. The risk for stroke, however, is still very low in absolute terms, even for these women.

Click the icon to see an image of stroke.

• Heart attacks. Studies suggest a higher risk for heart attacks in certain women taking OCs, regardless of their risk for blood clots. OCs can also adversely affect cholesterol, lipids, and blood sugar levels, depending on the balance of estrogen and progestins. Smoking is the significant risk factor. In fact, some studies have found no higher risk for heart attack in healthy women who do not smoke. The chance for a heart attack is higher in OC users who have high blood pressure, unhealthy cholesterol levels, or both.

Different progestins may affect risk for one or more of these complications. For example, the newer-generation progestins desogestrel (e.g., Desogen, Ortho-Cept) and gestodene (Minesse) may pose a higher risk for blood clots than those containing levonorgestrel. However, some evidence suggests that they pose a lower risk for heart attacks.

Breast Cancer. Studies have been conflicting about whether estrogen in oral contraception increases the chances for breast cancer, and if it does, which women are at risk. Some research supported a higher risk in women with a family history of breast cancer and who also used OCs before 1975, which contained high-dose estrogens and progestins. A reassuring 2002 study supported an earlier major study, with both finding no evidence that current OC use increases the risk for breast cancer. It also reported no higher risk in women who had taken OCs for 15 years of more or had taken them at young ages. Some issues remain unresolved. For example, the risk for women currently taking OCs around menopause (ages 45 to 64) is still unclear. OCs users with a family history of breast cancer or who carry the BRCA1 genetic mutation (although possibly not those with the BRCA2) may be at higher risk. Such women are at higher risk for breast cancer in any case.

Cervical Cancer. A number of studies, including a major analysis, has reported a strong association between cervical cancer and long-term use of oral contraception (OC). The risk is highest (up to four times the risk of nonusers) in women infected with human papillomavirus (HPV) who have taken OCs for ten years or more. (Women who are not infected with HPV have no significantly higher risk.) The reasons for this risk from OC use are not entirely clear. Some experts have suggested that the hormones in OCs might facilitate entry of the HPV virus into the genetic material of cervical cells. Certainly, women who use OCs are less likely to use a diaphragm, condoms, or other methods that offer some protection against sexually transmitted diseases, including HPV.

Click the icon to see an image of cervical cancer.

Other Complications. Other complications have been associated with the use of oral contraceptives:

• Taking oral contraceptives containing certain progestins (desogestrel in one study) also increased the risk for periodontal disease. Other progestins do not pose a risk for gum disease.
• There has been some debate over whether the progestin-only pill increases the risk for permanent type 2 diabetes in women who develop a temporary form of diabetes during pregnancy (called gestational diabetes). In any case, the low-dose combination pill does not to pose such a risk. Women with a history of gestational diabetes should discuss this controversy with their physician.
• Some evidence suggests that oral contraceptives may reduce lung capacity during exercise. In fact, there have been a few reports of exacerbation of asthma with OCs, but this is an uncommon effect.
• The pill can affect the liver and, in rare cases, has been associated with liver tumors, gallstones, or jaundice. Women with a history of liver disease, such as hepatitis, should consider other contraceptive options.

Interactions with Other Medications. Oral contraceptives can interact with a number of other medications and herbs.