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Polycystic Ovary Syndrome (PCOS)

PCOS is a set of symptoms that result from a hormonal imbalance affecting women and girls of childbearing age. Women with PCOS usually have at least two of the following three conditions:

Some women diagnosed with PCOS have the first two conditions listed above as well as other symptoms of PCOS but do not have cysts on their ovaries.

PCOS is the most common cause of anovulatory infertility, meaning that the infertility results from the absence of ovulation, the process that releases a mature egg from the ovary every month. Many women don't find out that they have PCOS until they have trouble getting pregnant.

PCOS can cause other problems as well, such as unwanted hair growth, dark patches of skin, acne, weight gain, and irregular bleeding.

Women with PCOS are also at higher risk for:

Symptoms of PCOS

In addition to the three features used to diagnose PCOS (absence of ovulation, high levels of androgens, and ovarian cysts), PCOS has many signs and symptoms, some of which may not seem to be related:

- No menstrual periods—called amenorrhea

- Frequently missed periods—called oligomenorrhea

- Very heavy periods

- Bleeding but no ovulation—called anovulatory periods

Because many women don't consider problems such as oily skin, extra hair growth, or acne to be symptoms of a serious health condition, they may not mention these things to their health care providers. As a result, many women aren't diagnosed with PCOS until they have trouble getting pregnant or if they have abnormal periods or missed periods.

Although PCOS is a leading cause of infertility, many women with PCOS can and do get pregnant. Pregnant women who have PCOS, however, are at higher risk for certain problems, such as miscarriage

Risk Factors for PCOS

PCOS affects between 5% and 10% of women ages 18 to 44. Because the criteria used to define PCOS are still changing, the exact number of women affected is unknown, but is estimated to be about one in every 10 to 15 women. Most women are diagnosed during their twenties or thirties, but PCOS may affect girls as young as 11 who haven't even had their first period.

Women are at higher risk for PCOS if they:

Causes of PCOS

Researchers and health care providers know that genetic and environmental factors contribute to the development of PCOS, but do not know exactly what causes PCOS.

Because the symptoms of PCOS tend to run in families, the syndrome is probably caused, at least in part, by a change, or mutation, in one or more genes. Recent research conducted in animal models suggests that in some cases PCOS may be caused by genetic or chemical changes that occur in the womb.

PCOS likely results from a combination of causes, including genes and environmental factors.

The Cause of PCOS Symptoms

Higher-than-normal levels of hormones called androgens cause most of the symptoms of PCOS.

The ovaries produce hormones, which are chemicals that control functions in the body. One of the hormones that the ovaries make is estrogen—sometimes called the "female hormone" because women's bodies make more of it than men's bodies do. The ovaries also make androgens—sometimes called "male hormones" because men's bodies make more of them than women's bodies do. Men and women need certain levels of both hormones for normal health.

In women with PCOS, the hormones are out of balance: these women have higher-than-normal levels of androgens and may have lower-than-normal levels of estrogen. High levels of androgens can:

Other symptoms of PCOS result from problems with insulin, another of the body's hormones. Insulin helps move sugar (also called glucose) from the bloodstream into cells to use as energy. When cells don't respond normally to insulin, the level of sugar in the blood rises. In addition, the level of insulin goes up as the body produces more and more of it to try to get glucose into the cells. Too much insulin increases the production of androgens, which then cause symptoms of PCOS. High levels of insulin can also increase appetite and lead to weight gain. High insulin levels are also linked to acanthosis nigricans.

Diagnosis of PCOS

Your health care provider may suspect PCOS if you have eight or fewer periods per year, excess body hair or acne, or irregular periods. After obtaining a clinical history suggestive of PCOS, your health care provider will rule out other conditions that may cause similar symptoms. Some of these conditions include:

After ruling out other conditions and before making a diagnosis of PCOS, your health care provider will do the following:

A woman who has at least two of the following three conditions may be diagnosed with PCOS:

Some women diagnosed with PCOS have the first two symptoms but no cysts on their ovaries.

Treatments for PCOS

Because PCOS has a broad range of symptoms, health care providers may use a variety of treatments for this condition and its symptoms.

The treatment(s) your health care provider suggests will depend on:

Because some of the common treatments for PCOS symptoms can prevent pregnancy or may harm the fetus during pregnancy, it's important to discuss your fertility goals with your health care provider while discussing treatment options. Be sure you fully understand your treatment options and their effects on pregnancy before deciding on a course of treatment.

You should also discuss the risks of treatments with your health care provider. All treatments have risks, and some of them can be serious. Also, some unhealthy lifestyle factors such as smoking can increase these risks, and thus you should discuss with your health care provider the best way to eliminate these practices.

Lifestyle Changes

In many cases, the first action that health care providers recommend for women with PCOS is that they make specific lifestyle changes, such as following a lower-calorie diet, losing weight, and getting more physical activity.

Losing weight and being more physically active can minimize many PCOS symptoms and related conditions. Even a 5% weight loss can improve many symptoms of PCOS.

No single diet or activity plan is known to work better than another in helping women with PCOS. Talk to your health care provider about designing a plan that's best for you.

Oral Contraceptives

Also called birth control pills or "the Pill," hormonal contraceptives can be used for the long-term treatment of women with PCOS who do not wish to become pregnant, and in fact they are the primary treatment for these women. Oral contraceptive pills contain a combination of the hormones estrogen and progestin. In women with PCOS, these hormones:

Oral contraceptives also can help lower the risk of certain types of cancers. There is no one oral contraceptive that works best for women with PCOS, but those that are less androgenic are more effective at treating the symptoms of PCOS.14 Please note that oral contraceptives, like all medications, are associated with some level of risk for side effects, some of them serious.

Discuss all possible side effects with your health care provider before making a final decision on a treatment.

Insulin-sensitizing Agents

These types of medications make the body more responsive to insulin and keep glucose levels more stable. In women with PCOS, these medications can help:

After four to six months of using these medications, women with PCOS may start ovulating naturally.

The U.S. Food and Drug Administration (FDA) has not approved insulin-sensitizing medications, such as metformin, specifically for treating PCOS. Even so, your health care provider may use these medications to treat your symptoms. Talk to your health care provider about any concerns you may have about these medications.


These medications either prevent the body from making androgens or limit the activities or effects of those hormones. In women with PCOS, anti-androgens can:

Because anti-androgens can cause birth defects, they are often taken with oral contraceptives to prevent pregnancy. Be sure to talk with your health care provider about the risks of these treatments, especially if you want to become pregnant.

As with insulin-sensitizing medications, anti-androgens are not approved by the FDA for the treatment of PCOS. At this time the best type of anti-androgen for treating PCOS symptoms is not known.

Removing or Hiding Unwanted Hair

There are many ways to remove excess or unwanted hair or to hide this hair without actually removing it. Women with PCOS can use the methods below instead of or in combination with other approaches:

Acne Treatments

Retinoids, antibacterial agents, and antibiotics may be used to treat acne. These products may be available in pills, creams, or gels. The specific treatment depends on the severity of the acne and how long it has been visible. Because retinoids can cause birth defects, you should not use them if you want to become pregnant.

Treatments for Infertility Resulting from PCOS

In most cases, fertility problems in women with PCOS result from the absence of ovulation (anovulation), but anovulation may not be the only reason for these problems. Before beginning treatment for infertility possibly related to PCOS, be sure that your health care provider rules out other causes.

Lifestyle changes, such as losing weight, can trigger body changes that facilitate conception in women with PCOS. Your health care provider may recommend that you try weight loss and other lifestyle changes before trying any medications to see if fertility returns and pregnancy occurs naturally. Research shows that lifestyle changes can help restore ovulation and improve pregnancy rates among women with PCOS. In one study of 11 women with PCOS who had menstrual dysfunction and lost more than 5% of their initial weight, nine either became pregnant or had their menstrual cycles become more regular.

If you have PCOS-related infertility, your health care provider may prescribe one of the following medications to help you get pregnant:

If you do not get pregnant with these first-line medications, your health care provider may suggest one of the following treatments:

If you do not get pregnant with the treatments listed above, your health care provider may suggest in vitro fertilization, or IVF. In this procedure, sperm and an egg are placed in a dish outside the body, in which fertilization occurs. Then a doctor places the fertilized egg into the uterus. IVF may offer women with PCOS the best chance of getting pregnant, and it may give health care providers better control over the risk of multiple births. But it can be expensive and may not be covered by health care insurance

Associated Conditions

Women with PCOS are at higher risk for several other health conditions, some of them serious. These conditions, while common in women with PCOS, are not considered symptoms of PCOS. Doctors usually treat the associated conditions in addition to treating PCOS. Conditions commonly associated with PCOS are described below.

Reference: National Institutes of Child Health and Human Development