Oral Contraception and Combination Hormonal Methods:

Oral contraceptives (birth control pills) 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 oral contraceptive combined brands now use lower estrogen doses than previous brands and are proving to be safe and effective with fewer side effects than earlier oral contraceptives.

For all oral contraceptive users, a check-up at least once a year is essential. It is also important for women to have their blood pressure checked 3 months after beginning the pill. Former pill users who want to bear children usually regain fertility in 3 - 6 months, but they may regain it even sooner.

Hormones Used in Contraceptives

Estrogen (Estradiol)

Estrogen is the major female hormone and is responsible for female characteristics. The estrogen compound used in most oral contraceptives is estradiol, which is always used with a progestin.

Effects on Reproduction. When used throughout a menstrual cycle with progesterone, estrogen suppresses the actions of other reproductive hormones (luteinizing hormone, or LH, and follicle stimulating hormone, or FSH) and prevents ovulation.

Progesterone (Progestin)

When used in contraception, progesterone is referred to by one of several names:

• Progesterone is the name for the natural hormone.
• Progestogen is a synthetic form.
• Progestin is the term for any hormone, natural or synthetic, that causes progesterone effects; it is used as the general term in this report.

Progestins may be used alone or with estrogen in oral contraceptives. In addition, certain specific progestins are used in other kinds of contraceptives, such as etonogestrel in the Implanon implant and depo-medroxyprogesterone acetate in the injectable contraceptive Depo-Provera.

Progesterone can prevent pregnancy by itself in several ways:

• Blocking luteinizing hormone (LH), one of the reproductive hormones important in ovulation
• Maintaining a powerful barrier against the entry of sperm into the uterus by keeping the cervical mucus thick and sticky

Progestins used in contraceptives are referred to as:

• Second generation (levonorgestrel, norethisterone).
• Third generation (desogestrel, gestodene, norgestimate, drospirenone). The third-generation progestins tend to have fewer side effects. Some studies suggest, however, they may pose a slightly higher risk for blood clots than the older progestins.

Combination Estrogen-Progestin Contraceptive Pills

Oral contraceptives that contain both estrogen and progestin are the more common type of oral contraceptive. At least 10 million American women and 100 million women worldwide use combination oral contraceptives. When they were first marketed in the early 1960s, oral contraceptives contained as much as 5 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.

The estrogen compound used in most oral contraceptives is ethinyl estradiol (also called estradiol, or EE). Fifty micrograms of estradiol is considered high dose, 30 - 35 micrograms are considered average dose, and 20 micrograms or fewer is low-dose. (The high doses found in current oral contraceptives are still much lower than earlier forms of the pill.) Doctors recommend using the lowest possible progestin and estrogen doses. Estrogen doses should not exceed 50 micrograms, as higher doses increase the risk for complications.

Many different types of progestins are used in combination with estradiol. Some common types of progestin, and popular combination oral contraceptive brands, include:

• Desogestrel is the progestrin used in Mircette. Approved in 1998, Mircette was the first oral contraceptive to offer a low estrogen dose and a new type of dosing regimen. Some studies suggest an increased risk for blood clots with desogesterel.
• Drospirenone is used in Yasmin and Yaz. (Yaz contains a lower dose of estrogen than Yasmin.) Because drospirenone increases blood levels of potassium, women should not use Yasmin or Yaz if they have kidney, liver, or adrenal diseases.
• Levonorgestrel is used in Seasonale and Seasonique, as well as many other oral and non-oral contraceptives.
• Norethindrone is used in Loestrin and Loestrin 24 Fe (which adds iron supplements to the placebo pills).
• Norgestrel is used in various generic and brand contraceptives.

Many types of medications and supplements (acetaminophen, anti-seizure drugs, antibiotics, St. John's wort) can interact with progestin and reduce its effectiveness. Make sure your doctor is aware of any drugs, vitamins, and herbal supplements that you take.

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

• Each pill in a 21-day pack contains estrogen and progestin. Women take 1 pill a day for 21 days, and then wait 7 days before starting a new 21-day pack.
• 28-day packs typically start with 21 hormone pills and add 7 placebo pills that do not contain hormones. After taking hormone pills for 21 days, a woman takes the inactive pills for 7 days. Some newer brands, like Yaz, use 24 days of active pills and 4 days of inactive pills. Mircette uses 21 days of low-dose progestin and estrogen, followed by 2 placebo days, and then 5 days of very low-dose estrogen. Loestrin 24 Fe uses 24 days of active pills followed by 4 days of iron-containing placebo pills.

Oral contraceptives 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 pills contain the same amount of hormones in each dose. Biphasic and triphasic pills contain different dosages of hormones within the pill packs. Because monophasic pills have a consistent amount of hormones, they tend to cause fewer hormone-fluctuating side effects than biphasic or triphasic pills. Research shows little difference in effectiveness between these three types of oral contraceptives. Monophasic pills are often recommended as the best first-choice for birth control pills.

Taking the Pills. A woman usually 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 cycle 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. If a woman has a 21-day pack, she waits 7 days before starting a new pack. If she is on the 28-day pack, she takes the 7 inactive pills. Women should use another method of birth control during the first month taking the pill.

If you skip one or more pills, take the following precautions:

• Missing the first pill in a new cycle. Take a tablet as soon as you remember and the next one at the usual time. Two tablets can be taken in one day. Use barrier contraception for 7 days after the missed dose. [See "Spermicidal and Barrier Contraception."]
• Missing a pill 2 days in a row. Take 2 pills as soon as you remember and then 2 more the following day. Also use back-up barrier contraception until the next pill cycle.
• Missing more than 2 days. Discard the pack, use a back-up birth control method, and begin a new cycle on the following Sunday, even if you have started bleeding.

Continuous-Dosing Oral Contraceptives

Standard oral contraceptives come in a 28-pill pack that contains 21 active pills and 7 inactive pills. Newer "continuous-dosing" (also called "continuous-use") oral contraceptives aim to reduce -- or even eliminate -- monthly periods and thereby prevent the pain and discomfort that often accompanies menstruation. Women who have medical conditions, (such as endometriosis), which cause heavy or painful menstrual periods may benefit from continuous-dosing oral contraceptives. These oral contraceptives contain a combination of estradiol and the progesterone levonorgestrel, but use extending dosing of active pills.

Seasonale, the first continuous-dosing contraceptive, was approved in 2003. It contains 81 days of active pills followed by 7 days of inactive pills. Women who take Seasonale have on average a period every 3 months. Seasonique, a follow-up to Seasonale, was approved in 2006. As with Seasonale, it produces about 4 periods a year. With Seasonique, a woman takes 84 days of levonorgestrol-estradiol pills followed by 7 days of pills that contain only low-dose estradiol.

In 2007, the Food and Drug Administration (FDA) approved Lybrel, which supplies a daily low dose of levonorgestrol and estradiol with no inactive pills. Because Lybrel contains only active pills, which are taken 365 days a year, it completely eliminates monthly menstrual periods. In clinical trials, 59% of women who took Lybrel completely stopped menstrual periods by the end of the first year. Some women, however, experienced occasional unscheduled bleeding or spotting during the first 3 - 6 months.

Progestin-Only Oral Contraceptives ("Mini-Pills")

Progestin-only pill brands include:

• Levonorgestrel (Plan B)
• Norethindrone (Micronor, Aygestin, Nor-QD)
• Norgestrel (Ovrette)

Progestin-only pills, which only contain progestins, are always sold in 28-day packs and all the pills are active. (An exception is Plan B, which is emergency contraception.) Progestin-only pills, which are also called “mini-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 3 hours, she should call her doctor about using back-up contraception for the next 2 days.

Progestin-only pill users experience even lighter periods than those taking combination pills. Some may not have periods at all. Because these pills do not contain estrogen, they may be a safer choice for women over age 35, smokers, and those who have other risk factors that contraindicate estrogen use.

Advantages of Oral Contraceptives

Oral contraceptives are the choice of most American women who use birth control, making them the most popular reversible contraceptives in the U.S. Oral contraceptives are among the most effective contraceptives. Failure rates are relatively low (9% with typical use) and are usually due to noncompliance.

Oral contraceptives also have the following advantages:

• Reduce menorrhagia (heavy menstrual bleeding) and, therefore, reduce the risk of anemia.
• Reduce dysmenorrhea (severe menstrual pain)
• May help reduce symptoms of premenstrual syndrome. Yaz is specifically approved for treating premenstrual dysphoric disorder (premenstrual depression).
• Improve acne
• Improve symptoms of 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.

• Reduce risks of ovarian cysts
• Possible protection against bone loss with estrogen-containing oral contraceptives
• Reduce risks of ovarian and endometrial (uterine) cancers with long-term use (more than 3 years)

Disadvantages of Oral Contraceptives

Common Side Effects. Many women experience some side effects during the first 2 - 3 months of birth control use. These side effects usually subside. Estrogen and progesterone have different side effects, and women on the combined pill may experience different effects from those on the progestin-only pill.

Common side effects of oral contraceptives include:

• Nausea and vomiting (can often be controlled by taking the pill during a meal or at bedtime)
• Headaches (in women with a history of migraines, they may worsen)
• Dizziness
• Breast tenderness and enlargement
• Irregular bleeding or bleeding between periods
• Weight gain

Newer formulations of combination pills that use low-dose estrogen, and newer progestins, may reduce and even lower the risk of many of these side effects, including weight gain.

Serious Side Effects. Symptoms of serious problems include severe abdominal pain, chest pain, unusual headaches, visual disturbances, or severe pain or swelling in the legs. If you experience any of these symptoms, you should immediately contact your doctor.

Potential Risks. Combination birth control pills can increase the risk of developing or worsening certain serious medical conditions. The risks depend in part on a woman’s medical history. You should discuss your health history with your doctor to determine if combination oral contraceptives are safe for you. This is especially important for women who are age 35 or older, smoke, or have a history of high blood pressure, high cholesterol or unhealthy blood lipid profile, diabetes, or migraine headaches.

Serious risks of birth control pills may include:

• Heart and Circulation Problems. Combination birth control pills contain estrogen, which can increase the risk for stroke, heart attack, and blood clots in some women. The risk is highest for women who smoke or have a history of heart disease risk factors (such as high blood pressure or unhealthy cholesterol/lipid levels) or cardiac events. Women who have certain metabolic disorders, such as polycystic ovary syndrome (PCOS), are also at higher risk for heart-related complications associated with these pills. Women who have migraines may possibly be at increased risk for stroke and may need to consider progestin-only pills or other contraceptive methods in place of combination oral contraceptives.
• Venous Thromboembolism. All combination estrogen/progestin birth control products carry an increased risk for blood clots in the veins (venous thromboembolism), which can lead to blood clots in the arteries of the leg or lung (pulmonary embolism). The risk is lower for oral contraceptives than for the birth control patch (Ortho Evra) or the ring (NuvaRing), which expose women to higher levels of estrogen than birth control pills. Women who smoke, who are obese, or who have heart disease risk factors may want to consider using alternatives to estrogen-containing contraceptives, such as progestin-only oral contraceptives ("mini-pills"), intrauterine devices, or barrier contraceptive methods.
• Diabetes. For women who have diabetes, birth control pills should not be taken if you smoke or if you have high blood pressure, vascular disease, kidney disease, or other diabetes-related health problems.
• Cancer Risks. Several studies have reported a strong association between increased risk of cervical cancer and long-term use of oral contraception. Women who take oral contraceptives for more than 10 years appear to have a much higher risk of human papilloma virus (HPV) infection than those who do not use oral contraceptives. Women taking oral contraceptives for less than 5 years have no significantly higher risk. Although studies have been conflicting about whether estrogen in oral contraception increases the chances for breast cancer, the most recent research indicates that oral contraceptive use does not significantly increase breast cancer risk. Women who have used oral contraceptives may have slightly more risk for breast cancer than women who have never used them, but this risk declines once a woman stops using birth control pills.
• Liver Problems. In rare cases, oral contraceptives have 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. Certain types of medications can interact with and decrease the effectiveness of oral contraceptives. These medications include anticonvulsants, antibiotics, antifungals, and antiretrovirals. The herbal remedy St. John’s wort can also interfere with birth control pills’ effectiveness

Other Methods for Administering Combination Hormones (Patch and Ring)

New methods of administering the combination of progestin and estrogen are now available. Failure rates with perfect use (0.1 - 0.6%) are similar to those of combined oral contraceptives.

Skin Patch. Ortho Evra was approved in 2002 as the first birth control skin patch. It contains a progestin (norelgestromin) and estrogen. The patch is placed on the lower abdomen, buttocks, or upper body (but not on the breasts). Each patch is worn continuously for a week and reapplied on the same day of each week. After three weekly patches, the fourth week is patch-free, which allows menstruation. (The patch remains effective for 9 days, so being slightly late in changing it should not increase the risk for pregnancy.)

The Ortho patch exposes women to higher levels of estrogen than most birth control pills, and therefore increases the risk for blood clots in the veins (venous thromboembolism). Venous thromboembolism can cause blockage in lung arteries and other serious side effects. Older women (over age 40) and women with risk factors for blood clots (such as cigarette smoking) may find other birth control products to be a safer choice. Discuss with your doctor whether the patch is appropriate for you.

Vaginal Ring. NuvaRing is a 2-inch flexible ring that contains both estrogen and progestin (etonogestrel). It is inserted into the vagina. Women can insert the ring by themselves once a month and take it out at the end of the third week to allow menstruation. It works well and may cause less irregular bleeding than oral contraceptives. Some women find it uncomfortable, and a few have reported vaginal irritation and discharge, but such problems rarely cause a woman to discontinue use. As with the patch, NuvaRing may put women who take it at higher risk for blood clots than oral contraceptives.