Polycystic ovary syndrome

What is it?

The NICHD defines the syndrome as "a group of symptoms linked to a hormonal imbalance" that may affect metabolism, the heart and blood vessels, inflammation and reproduction, and cause changes in the menstrual cycle, skin changes such as excess facial and body hair and acne, growths on one or both ovaries that are often clusters of follicles whose growth has stopped, as well as infertility. MedlinePlus defines it as a hormonal disorder in which a woman usually has at least two of: irregular ovulation, raised androgens, and growths (often cysts) in the ovary.

Name: the NICHD and MedlinePlus state that it is also known as "polycystic metabolic ovarian syndrome" (PMOS), and the NHS uses the new name and says it "used to be called polycystic ovary syndrome", describing it as a hormonal condition that can affect hair growth, periods, fertility and mood.

Prevalence according to WHO: it affects 10% to 13% of women of reproductive age, up to 70% of women with it remain undiagnosed; it is the most common cause of anovulation worldwide and a major cause of infertility, and a chronic metabolic condition that continues beyond the reproductive years. The CDC states that it may affect up to 5 million women (in the United States).

When it starts: WHO states that it may begin in adolescence but is often discovered when a woman has difficulty conceiving. The CDC states that it often begins at age 11 or 12 around the first period, and that many women do not know they have it until they try to conceive.

Causes

The exact cause is unknown (WHO, NICHD). The NICHD states that genetic and environmental factors contribute, and the NHS says it may relate to hormones such as insulin and testosterone not working properly. MedlinePlus lists genetics, androgen imbalance and insulin resistance (the body's inability to use insulin effectively) among possible factors.

The mechanism according to the NICHD: raised androgens disrupt the brain signals that regulate ovulation and cause follicles to cluster in the ovary. With insulin resistance the body secretes excess insulin to move sugar into cells, which raises androgen production, in a loop that sustains the symptoms and makes treatment harder.

Genetics: the NICHD states that researchers have identified 19 possible genetic variants that raise the risk, which may explain the variation in symptoms, and that men who carry these variants showed similar heart and metabolic features, suggesting the syndrome is not linked to the ovary alone. Animal studies suggest that exposure to high levels of androgens in the womb may raise the chance of the condition in a female offspring.

Risk factors

WHO states that women with a family history of the syndrome or of type 2 diabetes are more at risk. The NHS states that the likelihood is higher if a first-degree relative has it or the woman is of Asian descent.

The syndrome is strongly linked to obesity and insulin resistance: the NICHD states that about 4 in 5 women with it have obesity. This page does not cover other established risk factors for developing it.

Symptoms

Periods and reproduction: irregular, infrequent or absent periods (WHO); the NICHD mentions absent periods (amenorrhoea), skipped periods, heavy bleeding or bleeding without ovulation; and difficulty conceiving or infertility.

Signs of raised androgens: increased hair growth on the face, chest, abdomen or upper thighs (hirsutism) according to the NICHD, thinning or loss of scalp hair in a female pattern (WHO), and acne, which may be severe and not respond to usual treatments, and oily skin (NICHD, MedlinePlus).

Metabolic and other signs: weight gain, especially around the middle, and thick, dark, velvety patches of skin (acanthosis nigricans) appearing in body folds such as the neck and armpits (NICHD, CDC, NHS). The NHS mentions tiredness and mental health problems such as depression and anxiety. MedlinePlus stresses that symptoms vary greatly from one woman to another.

How is it diagnosed?

Criteria: according to WHO diagnosis requires at least two of: signs of raised androgens or raised blood testosterone, irregular or absent periods, and polycystic ovaries on ultrasound. WHO states that some women with it do not have polycystic ovaries. The NICHD requires that the raised androgens not be caused by other causes or conditions, and states that approaches differ on which two features are required.

Tests: MedlinePlus says: "There is no specific test for the syndrome", and assessment relies on medical history, clinical examination, pelvic examination, ultrasound and hormone tests. The NHS mentions blood tests for hormones and insulin resistance, and that an ultrasound of the ovaries is only done for those over 18.

Adolescents: the NICHD states that current guidelines are for adults and there are no diagnostic criteria for the syndrome in adolescents; some may be classed as "at risk" and reassessed at adulthood. After diagnosis the CDC advises asking about screening for type 2 diabetes.

Treatment

The treatment categories usually used are listed here; this is not a prescription. The doctor chooses the plan according to each person's condition; do not change any medicine or dose without a specialist.

There is no cure for the syndrome (WHO, NHS), but according to WHO treatment improves quality of life, helps fertility, reduces the risk of endometrial thickening and cancer, and helps prevent heart and vascular events in the long term. The NICHD says treatment depends on symptoms, general health and pregnancy plans, and WHO calls for shared decision-making that respects each woman's values and preferences. The plan is determined by the doctor.

Lifestyle: WHO says healthy eating and physical activity matter for all women with it even if they do not lead to weight loss; the NICHD mentions weight loss and increased activity to ease symptoms and heart disease risk. The NHS suggests talking therapy if symptoms cause depression or anxiety.

Medicine categories as the sources list them (determined by the doctor): combined hormonal contraceptive pills to regulate the cycle, which may also reduce acne and excess hair (for those not planning pregnancy), anti-androgens for excess hair and acne, medicines that improve insulin sensitivity, acne treatments, and hair-removal methods (creams, mechanical methods, electrolysis and laser) — according to the NICHD, WHO, MedlinePlus and NHS. The NICHD cautions to discuss pregnancy plans before treatment because some options prevent pregnancy or may harm the foetus.

When pregnancy is desired: WHO and the NICHD mention lifestyle changes (the NICHD states that even modest weight loss may restore ovulation and improve pregnancy rates), oral ovulation-induction medicines, injectable hormones (with a higher risk of multiple pregnancy), medicines that improve insulin sensitivity (they improve ovulation, but the NICHD states they do not raise the pregnancy rate), laparoscopic ovarian drilling (its benefits are unclear and it is not recommended for everyone according to the NICHD), and in vitro fertilisation when other treatments do not succeed.

Do not start or stop any medicine without your doctor; the CDC says some medicines help ovulation and reduce acne and hair growth, and the right one is chosen with your healthcare provider.

Follow-up

WHO advises seeking care early to manage symptoms and protect health during and after the reproductive years, and the CDC advises asking about screening for type 2 diabetes and how to manage it. WHO states that pregnancy in women with the syndrome needs extra monitoring because of a higher risk of complications. This page does not cover specific screening schedules.

Complications

Metabolic: the NICHD states that more than half of women with the syndrome will have type 2 diabetes or prediabetes before their early forties, that 25% to 45% have metabolic syndrome, and about 4 in 5 have obesity. The CDC says: "More than half of women with PCOS will have type 2 diabetes by age 40", and mentions gestational diabetes.

Heart, vessels and liver: the sources mention a higher risk of heart disease, high blood pressure and hardening of the arteries (NICHD, WHO), abnormal cholesterol (high LDL and low HDL) and stroke (CDC), and fatty liver (the NHS calls it non-alcoholic fatty liver disease).

Womb: the NICHD states that absent or irregular periods may cause the womb lining to build up and thicken, raising the risk of endometrial cancer, while the evidence for a link with breast and ovarian cancer is inconclusive. WHO and MedlinePlus mention endometrial thickening and cancer.

Sleep and mental health: obstructive sleep apnoea is far more common in women with the syndrome (NICHD). WHO mentions anxiety, depression, eating disorders and negative body image.

Pregnancy: the NICHD states that the risk of miscarriage is three times higher, and that the risk of gestational diabetes, pre-eclampsia, high blood pressure, preterm birth and caesarean delivery is higher, with possible complications for the baby. WHO says women with the syndrome can be supported to conceive with extra monitoring.

Prevention

This page's sources did not mention a proven way to prevent the syndrome, as its cause is unknown (WHO). As for its complications, the CDC says losing weight when it is excessive and increasing physical activity reduce the risk of type 2 diabetes, and WHO advises a healthy lifestyle and seeking care early.

Living with it

Social impact: WHO states that symptoms such as infertility, obesity and excess hair may attract social stigma, which can affect family relationships, work, sense of belonging and mental health. The NHS advises seeing a doctor if symptoms affect daily life, work and relationships, and talking therapy for depression or anxiety.

Fertility: the NICHD says infertility linked to the syndrome is "treatable in most cases", and women with it can conceive naturally or with medical help. Follow-up is long-term because the syndrome is a chronic metabolic condition that continues beyond the reproductive years (WHO).

Common questions