Polycystic ovary syndrome (PCOS) is a hormonal disorder, but the condition — which may affect up to 18 percent of people with ovaries globally, per an October 2022 entry in the Lancet Regional Health-Europe — is also connected to fertility, metabolism and even heart, skin and mental health.
In other words, PCOS is complicated. But the more we understand about the disorder, the better we can become at treating it and improving quality of life for those who have it.
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Here's a deeper look at PCOS statistics and facts, including who PCOS affects, how it's diagnosed and how it's linked to other health conditions.
How Common Is PCOS?
PCOS is the most common endocrine disorder in people with uteruses of reproductive age. About 10 percent of people with ovaries will be affected by PCOS during those reproductive years, according to the Endocrine Society.
This means it's a fairly common disorder worldwide and in the United States.
What Are the Causes of PCOS?
Experts believe a combination of genetics, lifestyle factors and other health factors play into the cause of PCOS. These factors lead to an imbalance of hormones, especially increased levels of androgens, per the Mayo Clinic.
Is PCOS Genetic?
About 20 to 40 percent of people with PCOS have a mother or sister with the condition, per the National Library of Medicine. PCOS is considered an ancient disorder passed down through families, and it's likely that a variety of genetic components contribute to it.
How Is PCOS Diagnosed?
One tricky thing about PCOS is its diagnosis. The reason? There are three different criteria used, according to a June 2020 study in Progress in Preventive Medicine, which can lead to inconsistencies in who's diagnosed and when.
The three main criteria are:
1. Hyperandrogenism: This refers to an excess of the hormone androgen, which can lead to either excessive hair growth on the face, chest and back or hair loss (called hirsutism); acne; weight gain; and developing other biological-male characteristics (called virilization). It's considered the "hallmark" feature of PCOS, according to a November 2019 article in the Egyptian Journal of Medical Human Genetics.
2. Chronic oligo-ovulation or anovulation: About 70 percent of anovulation — a lack or absence of ovulation — cases are caused by PCOS, per the Cleveland Clinic. Ovulation is the release of an egg from the ovaries, which results in pregnancy if the egg is fertilized or menstruation if it's not.
These people might have abnormal uterine bleeding due to ovulatory dysfuntion, usually marked by fewer than eight periods in one year, or amenorrhea, which means no period for more than three months, per Merck Manual.
3. Polycystic ovaries: About 90 percent of people with PCOS who have excess hair growth also have multiple cysts on their ovaries, according to a December 2013 article in Clinical Epidemiology. (Note: This is the most recent number collected.) It's important to note here that just because you have cysts on your ovaries, this doesn't mean you have PCOS.
Indeed, later in the same article, the authors report that 20 to 30 percent of people with ovaries who don't meet the medical criteria for PCOS have multiple ovarian cysts.
In order to make a PCOS diagnosis, doctors must rule out other related disorders, such as Cushing's syndrome (which can cause all three diagnostic criteria, as well as insulin resistance) and androgen-secreting tumors.
Worldwide Prevalence of PCOS
Because people with PCOS can have a wide range of symptoms and because doctor education on the condition is relatively lacking, it's likely that PCOS is under-diagnosed. In fact, it's estimated that 50 to 75 percent of people with PCOS don't know they have it, according to a November 2018 paper in the International Journal of Environmental Research and Public Health.
With that in mind, somewhere between 5 and 18 percent of people with ovaries worldwide are estimated to have PCOS, per the October 2022 entry in the Lancet Regional Health-Europe.
PCOS Prevalence by Country
Here are the estimated percentages of people with ovaries in their reproductive years who have PCOS, keeping in mind that diagnostic methods can vary by country:
PCOS Demographics for the U.S.
Because of the challenges mentioned above, it's difficult to get a clear picture of how many people have PCOS in the U.S.
By region, PCOS is most common in the southern U.S. (47.5 percent), followed by North Central (23 percent), West (18.7 percent) and the Northeast (10.3 percent), according to the November 2018 paper in the International Journal of Environmental Research and Public Health.
Here are some other estimates:
- Somewhere between 6 and 12 percent of people with ovaries in the U.S. have PCOS, according to the Centers for Disease Control and Prevention (CDC), though the actual number may be higher.
- 5 million people of childbearing age are estimated to be affected, according to the CDC.
- About 1 in 10 people with ovaries in their reproductive years have the condition, per the Office on Women's Health.
- PCOS is the most common endocrine abnormality among people with ovaries of reproductive age in the U.S., according to a June 2015 article in the International Journal of Endocrinology.
- According to the CDC, PCOS can happen at any age after puberty, but most people find out they have PCOS in their 20s or 30s, or when they try to become pregnant.
PCOS by Race/Ethnicity
This condition can be seen in people of all races and ethnicities, but research shows that some groups are more affected.
There's not a lot of data among larger populations broken down by race or ethnicity. But one July 2017 article in Oncotarget found that the prevalence of PCOS was as follows:
- Chinese: 4.4 to 7.3%
- White: 4.8 to 6.3%
- Middle Eastern: 5.3 to 18.6%
- Black: 5.3 to 7.1%
The Cost of PCOS
As of 2020, identifying and managing PCOS costs the U.S. health care system more than $8 billion per year, according to a January 2022 review in the Journal of Clinical Endocrinology & Metabolism.
PCOS, Fertility and Pregnancy
PCOS is tied to infertility. Here, we'll break down what that means:
PCOS and Infertility
Research shows the infertility rate for people with PCOS is higher than in people without the condition.
- The rate of infertility is estimated to be 15 times higher in people with PCOS than in those without the condition, according to an April 2015 study in the Journal of Women's Health.
- According to the World Health Organization (WHO), PCOS is the most common cause of anovulatory infertility (when you don't ovulate, or release an egg to fertilize).
- 80 percent of people with anovulatory infertility have PCOS, according to a September 2017 paper in Women's Health.
PCOS and Pregnancy Odds
People with PCOS can get pregnant, but the odds are typically lower because they tend to ovulate less. Here's a closer look at the numbers:
- Infertility drugs can help those with PCOS get pregnant. Clomiphene citrate (CC), a medication used as first-line treatment to induce ovulation, assists about 75 to 80 percent of those with PCOS to ovulate, with a reported conception rate of 22 percent per cycle, according to a December 2019 article in Clinical Medicine Insights: Reproductive Health.
- The clinical pregnancy rate of letrozole, another first-line treatment to induce ovulation, was found to be higher than CC in one February 2014 review of 26 randomized controlled trials in the Cochrane Database of Systematic Reviews. (Note: This is the most recent research done in this area.)
- Weight loss — specifically, shedding 5 to 10 percent of body weight — might help with re-establishing ovulation and thus getting pregnant, according to a 2015 chapter in A Case-Based Guide to Clinical Endocrinology.
- While it may take people with PCOS longer to get pregnant, family size isn't necessarily reduced compared to those who don't have the condition, according to a July 2012 study in Human Reproductive Update. (Note: This is the most recent research done in this area.)
- PCOS presents a moderate risk of ovarian hyperstimulation syndrome, a potential complication of fertility medications that stimulate egg production, in up to 7.5 percent of people with PCOS who conceive after in vitro fertilization (compared to 2.7 percent in people without PCOS), according to the September 2017 paper in Women's Health.
Pregnancy Complications and PCOS
If you have PCOS and get pregnant, you're at an increased risk of the following:
- Early pregnancy loss: It's estimated to be three times greater in those with PCOS, per the same 2017 Women's Health paper.
- Miscarriage: People with PCOS are at 41 percent higher risk of miscarriage than those without PCOS, per an August 2019 review in Reproductive Biomedicine Online.
- Gestational diabetes (GDM): One study in the 2017 Women's Health paper found a two- to threefold increase in GDM in those with PCOS.
- Pregnancy-induced hypertension (PIH) and preeclampsia (PET): Research has found a two- to fourfold increase in these conditions in people with PCOS, per a January 2019 study in the Journal of Pregnancy.
- Premature delivery: These rates are increased as well, especially in those with hyperandrogemia. One study found the rate of premature delivery in those with PCOS to be 21 percent compared to 12.5 percent in a control group, per the 2017 Women's Health paper.
- Cesarean sections (CS): Elective and non-elective CS were doubled in a PCOS population compared to a non-PCOS population, per the 2017 Women's Health paper.
PCOS Comorbidities and Complications Data
Infertility is a big complication of PCOS, yes, but it's not the only major health issue associated with the condition. Research has linked PCOS to a number of health complications.
Though researchers aren't sure if PCOS is the cause of these issues or vice versa, or if other conditions cause both, they do know that these are seen often when you have PCOS.
- Higher weight: More than half of people with PCOS have overweight or obesity, per the CDC. The relationship between weight and PCOS is complicated, according to the CDC, and more research is needed to understand it.
- Insulin resistance: About 50 to 70 percent of people with PCOS have insulin resistance, according to the International Journal of Environmental Research and Public Health. Excess amounts of glucose and insulin in the blood can lead to metabolic syndrome and type 2 diabetes, according to The Eunice Kennedy Shriver National Institute of Child Health and Human Development.
Here are some health concerns PCOS puts you at higher risk for, according to the CDC unless otherwise specified:
- Diabetes: At least half of people with PCOS will develop diabetes or prediabetes (glucose intolerance) by the age of 40. PCOS has been defined as a nonmodifiable risk factor for type 2 diabetes by the American Diabetes Association, and between 4 and 10 percent of people with PCOS have type 2 diabetes (that's twice the prevalence in age- and weight-matched healthy people without PCOS), according to the June 2015 article in the International Journal of Endocrinology.
- Cardiovascular disease: PCOS puts you at higher risk for heart disease, and that risk increases with age, per the CDC.
- High blood pressure: If you have PCOS, you're more likely to have high blood pressure, which is a leading cause of heart disease and stroke, per a March 2020 review in Reproductive Biology and Endocrinology.
- Unhealthy cholesterol: People with PCOS can have higher levels of LDL (bad) cholesterol and lower levels of HDL (good) cholesterol, raising their heart disease and stroke risk, per the CDC.
- Sleep apnea: Sleep disturbances are twice as common in people with PCOS than those without, per a February 2015 study in Human Reproduction. Sleep apnea, in particular, involves breathing interruptions during sleep that can raise your risk of heart disease and diabetes.
- Depression and anxiety: People with PCOS are at increased risk for these mental health conditions, per the CDC.
- Endometrial cancer: There have been associations made between ovulation, obesity, insulin resistance and diabetes (all common with PCOS) and endometrial cancer, however more research needs to be done to support these complex connections, per a December 2016 review in Fertility Research and Practice.
- Fatty liver: Fatty liver affects 15 to 55 percent of people with PCOS, but it can be improved with diet and lifestyle changes, per an October 2014 review in the World Journal of Gastroenterology. (Note: This is the most recent research done in this area.)
- Progress in Preventive Medicine: “Cross-sectional Study on the Knowledge and Prevalence of PCOS at a Multiethnic University.”
- International Journal of Environmental Research and Public Health: “Geographical Prevalence of Polycystic Ovary Syndrome as Determined by Region and Race/Ethnicity.”
- Centers for Disease Control and Prevention: “PCOS (Polycystic Ovary Syndrome) and Diabetes”
- International Journal of Endocrinology: “Regulation of Cardiovascular Metabolism by Hormones and Growth Factors.”
- Journal of Women’s Health: “Prevalence of Infertility and Use of Fertility Treatment in Women with Polycystic Ovary Syndrome: Data from a Large Community-Based Cohort Study.”
- Human Reproductive Update: “Health and fertility in World Health Organization group 2 anovulatory women.”
- American Diabetes Association: “Screening for type 2 diabetes.”
- The Eunice Kennedy Shriver National Institute of Child Health and Human Development: “Are there disorders or conditions associated with PCOS?”
- Egyptian Journal of Medical Human Genetics: "Hyperandrogenism in polycystic ovarian syndrome and role of CYP gene variants: a review".
- Clinical Epidemiology: "Epidemiology, diagnosis, and management of polycystic ovary syndrome."
- Springer: "Case-Based Guide to Clinical Endocrinology: Getting Pregnant with PCOS."
- Clinical Medicine Insights: Reproductive Health: "Fertility Treatment Options for Women With Polycystic Ovary Syndrome."
- Cochrane database of systematic reviews: "Aromatase inhibitors for subfertile women with polycystic ovary syndrome"
- Oncotarget: "The prevalence of polycystic ovary syndrome in reproductive-aged women of different ethnicity: a systematic review and meta-analysis."
- The Lancet Regional Health-Europe: "Polycystic ovary syndrome: What more can be done for patients?"
- Cleveland Clinic: "Anovulation"
- National Library of Medicine: "Polycystic Ovary Syndrome"
- Queensland Health: "7 Signs You Have Polycystic Ovarian Syndrome"
- University of Ottawa: "Healthcare Delivery for Polycystic Ovary Syndrome in Canada: Exploring Women’s Experiences with Diagnosis and Management and Identifying Areas of Improvement"
- Sehat Kahani: "PCOS and The Health of Pakistani Women – What are the Challenges ahead?"
- Journal of Endocrinology & Metabolism: " Health Care-Related Economic Burden of Polycystic Ovary Syndrome in the United States: Pregnancy-Related and Long-Term Health Consequences"
- Reproductive Biomedicine Online: "A meta-analysis of pregnancy-related outcomes and complications in women with polycystic ovary syndrome undergoing IVF"
- Journal of Pregnancy: "The Association of Polycystic Ovary Syndrome and Gestational Hypertensive Disorders in a Diverse Community-Based Cohort"
- World Journal of Gastroenterology: "Review of nonalcoholic fatty liver disease in women with polycystic ovary syndrome"
- Human Reproduction: "Sleep disturbances in a community-based sample of women with polycystic ovary syndrome"
- Reproductive Biology and Endocrinology: "Risk of hypertension in women with polycystic ovary syndrome: a systematic review, meta-analysis and meta-regression"
- Fertility Research and Practice: "Polycystic ovary syndrome and risk of endometrial, ovarian, and breast cancer: a systematic review"
- Endocrine Society: "Polycystic Ovary Syndrome"
- Mayo Clinic: "Polycystic Ovary Syndrome"
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