Hormonal Methods of Contraception

There are several different hormonal methods of birth control. The differences among them involve:

 
• The type of hormone;  
• The amount of hormone; and  
• The way the hormone enters a woman’s body.

The hormones can be estrogen and/or progesterone. These hormones may be oral (taken by mouth), implanted into body tissue, injected under the skin, absorbed from a patch on the skin, or placed in the vagina. The mode of delivery determines whether the hormonal exposure is continuous or intermittent.

The different hormonal types of birth control are comparable in that they are all highly effective and all are reversible. However, none of the hormonal methods of birth control protect a woman against sexually transmitted infections.

The pill for women is an oral contraceptive made from synthetic hormones. The pill is considered to be 97 to 99% effective, if used properly. The pill is also fully reversible. The pill has been available since 1960, and it is estimated that more than 10 million American women currently use birth control pills.

There are two types of birth control pills available:

 
1. The combination pill (currently 39 brand names); and  
2. The minipill (currently 3 brand names).

1. The combination pill

The combination pill contains the hormones estrogen and progestin, a form of progesterone. When a woman uses the combination pill, the eggs in her ovaries do not mature and she does not ovulate. She doesn’t become pregnant because no egg is available to be fertilized by a sperm.

The combination pill comes in 21-day packs or 28-day packs depending on the manufacturer. The 21-pill pack has pills for 21 “on” days and no pills for the 7 “off” days that follow. The 28-pill pack has active pills for the first 21 “on” days and 7 inactive (placebo) or reminder pills for the following 7 “off” days. For more, please read the Oral Contraceptives article.

2. The Minipill

The minipill only contains one hormone, progestin. Progestin thickens the cervical mucus, making it more difficult for sperm to pass through the cervix. It also makes the lining of the uterus less receptive to the implantation of a fertilized egg. The progesterone-only pill is sometimes recommended for women who have medical reasons for which they must avoid taking estrogen hormones. (These reasons include liver disease, certain types of blood clots in the veins, breast cancer, and uterine cancer). In addition, it is often recommended in nursing mothers because it has no adverse affects on breastfeeding. Indeed, extended breastfeeding, as well as delay in the need for formula supplementation has been observed in breastfeeding users of the minipill.

The minipill is taken every day. There are no “on” or “off” days with the minipill.

No matter which type of birth control pill a woman uses, she should take it every day at the same time in order to establish a routine. The woman needs to minimize the chance she will forget to take the pill, which is not an uncommon occurrence. This is especially critical in the case of the progestin-only pill (minipill). Forgetting to take the minipill, or taking it at varying times of the day, can significantly impair its effectiveness in contraception. This is due to the low dose of the minipill causing its effects to wear off rapidly if the pill is missed.

When a woman begins taking the pill, she is not protected from pregnancy until she has been taking the pill for 10 consecutive days in a row. If a woman forgets to take a pill after she has started, she is at risk for getting pregnant. She needs to use an alternate form of birth control for the seven days following the first missed pill.

If she only misses one pill, she should take it as soon as she remembers, even if it means taking two pills in the same day. If she misses two pills, she should take both of them as soon as she remembers, plus the pill for that day at her regular time. If she misses three pills, she should discontinue use of the pill for four more days to complete one week and then begin taking a new pack of birth control pills, whether she has a menstrual period or not. She must use an alternate form of birth control, or abstain from sexual activity during the week that she stops taking her pills. If a woman continually forgets to take her pills, perhaps she should consider a different method of birth control.

The pill may partially lose its effectiveness if a woman vomits or has diarrhea for any reason. Some medications, including certain sedatives and some antibiotics such as penicillin and tetracycline, may reduce the effectiveness of the pill. Research in this area is ongoing. A woman should ask her health care professional about these matters and the necessity of using a back up method of birth control if any of these conditions exist.

Some women experience temporary symptoms of spotting or light vaginal bleeding, breast tenderness, and nausea during the first 1 to 3 months of taking the pill. Nausea can be helped if the pill is taken after a meal. While women sometimes fear weight gain with oral contraceptives, studies of the low-dose preparations demonstrate that there is no significant weight gain with oral contraception and no major difference in weight change comparing various contraception products. Negative mood changes, such as depression, and pigmented patches of skin on the face (melasma) may occur with oral contraceptive use. Because the progesterone in women can cause thinning of the lining of the uterus, some women may experience loss of menstrual periods (amenorrhea). Oral contraceptive-induced amenorrhea happens in about one percent of women in the first year of use. As long as the woman is properly taking her pills, amenorrhea is not harmful and it does not signal any loss of effectiveness of the pills. Most side effects from the combination pill or the minipill decrease after 2 to 3 months of use. It is important to remember that because most side effects of oral contraceptives decrease in the first 2-3 months of use, women should try to avoid switching pills prior to an adequate trial. Trying to stick with any given product for 2-3 months may be necessary to really determine whether or not it will be tolerated over time. Switching too early to another brand may only needlessly subject the woman to the possibility of similar side effects starting all over again with the new pill.

There is no increased risk of birth defects in babies born to women who have taken the pill but a woman should not use either type of pill if she is pregnant. A woman who is breastfeeding should not use the combination pill because it can reduce the amount of her breast milk and the concentration of proteins and fat in her breast milk. Additionally, her breast milk will contain traces of the hormones from the pill. However, in contrast to the combination pill, the minipill is routinely used in lactating women.

Women who smoke and take the pill are at increased risk of heart disease and stroke. There is no increased risk of heart attack or stroke among healthy non-smoking women who use the pill. Blood clots in the legs and elsewhere are slightly more frequent with low-dose oral contraceptives, but the risk is very low, and lower than the increased risk of clotting that occurs with pregnancy. Nevertheless, oral contraceptives are not recommended for women with clotting tendencies (such as cardiolipin antibody associated clotting), known coronary heart disease, stroke, unevaluated breast lumps, vaginal bleeding, or breast cancer. Smokers over 35 years of age should not use oral contraceptives, nor should women with a significant liver disorder.

A woman should contact her health care professional immediately if she experiences any of these side effects while taking the pill (or anytime, for that matter):

 
• Severe headache;  
• Leg cramps;  
• Change in vision including blurred vision, vision loss, or flashing lights;  
• Abdominal pain;  
• Chest pain;  
• Shortness of breath;  
• Coughing up blood; or  
• Leg swelling or pain.

There are a number of benefits to taking the pill. Both the combination pill and the minipill can regularize a woman’s menstrual cycle and reduce her menstrual flow and menstrual cramps. There is evidence that the pill protects against cancer of the ovary and uterus as well as pelvic inflammatory disease (PID) and iron deficiency anemia. The combination pill can reduce acne (although maximal acne reduction may take 6 months to occur), the risk of an ectopic pregnancy, noncancerous breast cysts, and ovarian cysts. According to a large study, the combination pill confers no long-term risk of breast cancer. In addition, a woman who has taken the pill is less likely to develop rheumatoid arthritis and osteoporosis. Users of oral contraceptives have experienced significant decreases in excessive menstrual flow and in occurrence and severity of menstrual cramps.

A woman’s menstrual periods should begin again within about 6 months of stopping the oral contraceptive pill, however, the length of delay before a woman’s period returns after stopping the pill varies from woman to woman.Oralwoman. Oral contraceptives are about 97 percent effective in preventing pregnancy. The pill does not protect a woman against sexually transmitted infections.

Injected Contraceptive: Depo-Provera, Lunelle

There are two methods of birth control administered by injection, Depo-Provera and Lunelle.

Depo-Provera

Depo-Provera is medroxyprogesterone, a synthetic long-acting form of the hormone progesterone. Depo-Provera is similar to the birth control minipill in that it does not contain estrogen. Like other progesterone-based contraceptives, Depo-Provera acts by preventing the release of the egg from the ovary (ovulation) and by promoting thick cervical mucus that impedes the sperm’s progress.

Depo-Provera must be injected by a health care professional every 3 months (12 weeks). The injection is given in the buttocks or upper arm, where it may cause minimal soreness for a day or so. The injection must be administered within the first five days of a woman’s menstrual period. She is then protected from pregnancy within 24 hours of receiving the injection.

A woman may stop having periods altogether after using Depo-Provera for one year. After 2 years of use, 70% of women will have no menstrual bleeding. Menstrual periods stop because the Depo-Provera causes the ovaries to go into a “resting” state. When the ovaries do not release an egg every month, the regular growth of the lining of the uterus does not occur and no uterine lining is shed during the subsequent menstrual cycle.

A woman’s menstrual periods should begin again within 6 to 18 months after she stops taking the Depo-Provera injections. A woman can also become pregnant, usually within 12 to 18 months, once she stops using Depo-Provera. If a new mother does not breastfeed her baby, she can resume Depo-Provera injections right after childbirth. Mothers who are breastfeeding can safely begin Depo-Provera injections 6 weeks after childbirth. The injections do not reduce the flow of her breast milk and no harmful effects on the baby have been noted.

The most common side effects of Depo-Provera injections are irregular menstrual cycles, cessation of menstrual periods, and weight gain. Other side effects may include nervousness, dizziness, stomach discomfort, headaches, fatigue, or breast tenderness. It is important that a woman realize that once she has been injected with Depo-Provera, any side effects she may experience cannot be neutralized or eliminated. She has to tolerate these side effects until the Depo-Provera wears off, typically 3 months later.

Depo-Provera may contribute to risk factors associated with the development of osteoporosis by decreasing the amount of calcium stored in the body. This in turn can increase the risk of developing thinner and weaker bones. A woman using Depo-Provera is encouraged to be sure that she has an adequate dietary intake of calcium. Her previous bone density is normally restored when the Depo-Provera is discontinued.

Conversely, Depo-Provera may be possible when avoidance of estrogen is prudent for medical reasons (see oral contraceptives). A qualified health care provider should be able to help make the proper distinction.

Lunelle

Lunelle is the other injectable birth control option. It is a combination of estrogen and progesterone, whereas Depo-Provera is progesterone alone. Lunelle is administered monthly. The contraceptive protection is probably due to Lunelle’s ability to prevent ovulation, and decrease penetration of sperm due to alterations in cervical mucus.

Side effects of Lunelle are similar to those of Depo-Provera, listed above, except that less is known about Lunelle’s effects on bone density compared to Depo-Provera.

Both Depo-Provera and Lunelle should not be used by women who have a history of breast cancer, blood clots, liver disease, unexplained vaginal bleeding, or stroke. A woman on Depo-Provera should contact her health care professional if she experiences a heavy menstrual flow, severe abdominal pain, headaches, or depression.

Both injection contraceptives are over 99% effective if the injections are received according to the correct schedule. A woman using either type of injection contraceptive has the advantage of being capable of becoming pregnant at a later time, if desired, simply by discontinuing use. The injections cost about the same as birth control pills for a similar period of time. Depo-Provera does not increase a woman’s risk of cancer, including breast cancer, and greatly reduces her risk of developing uterine cancer. Similar research will likely be reported in the future for Lunelle.

Neither Depo-Provera nor Lunelle protects against sexually transmitted infections.

Contraceptive Patch: Ortho-Evra

An adhesive patch has been developed that will provide a contraceptive through the skin. This method is called a transdermal (through the skin) delivery system. The patch is about the size of a half-dollar and can be worn on the arm, abdomen or buttocks. A woman wears the patch for a week and then replaces it with a new patch.

These patches, called Ortho-Evra, are similar to the pill in that it contains both estrogen and progesterone. Ortho-Evra should be just as effective in preventing pregnancy as the pill. Ortho-Evra is similar to the pill in that it suppresses ovulation. Because the hormone in Ortho-Evra is delivered in a continuous steady flow, much like the Norplant implants, the cyclical “peak and valley” aspects of the pill are largely avoided. In general, a woman should not experience side effects such as nausea or vomiting with Ortho-Evra because the hormones from the patch enter the body through the skin rather than the digestive system. However, women who have medical reasons why oral contraceptives are not recommended may find that their prescribing physician also recommends against Ortho-Evra, because of the similarity in the hormone ingredients of both types of contraceptives.

A woman only needs to remember to replace the patch once a week instead of being required to remember taking a pill every day. The patch is stopped for 1 week every 4 weeks, to allow for a menstrual flow to occur.

It is important to ensure that the patch makes good contact with the skin. The patch could be a problem for those women who sweat a lot and/or take frequent showers because moisture can interfere with the patch’s contact with the skin. Some women may also experience skin irritation at the site of the patch.

The Ortho-Evra patch, approved for use by the FDA in 2001, is similar in effectiveness to Norplant or progesterone IUD.

As with all other hormonal methods of birth control, the Evra patch will not protect a woman against sexually transmitted infections.

 

Vaginal Ring (Nuvaring)

A ring-shaped device that contains the female hormone estradiol can be placed in the vagina. It remains in place for 3 weeks continuously, then it is removed for 1 week to allow for a menstrual period. It continuously releases low levels of the hormone into the bloodstream for the entire 3 weeks.

There is currently one brand available, called NuvaRing. It is about 99% effective in preventing pregnancy, the same high effectiveness as the other hormonal methods of contraception.

NuvaRing does not protect against sexually-transmitted infections. As with other non-oral forms of contraception, it is not known whether the same side effects or risks apply to NuvaRing as for oral contraceptives. It is probably safest to assume that contraindications are the same for patches and vaginal rings as for oral contraceptives.

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SOURCE: Archives of Pediatrics & Adolescent Medicine