Polycystic ovary syndrome (PCOS / PMOS)

Overview

WHO estimates that PCOS affects about 10–13% of reproductive-aged women and that many remain undiagnosed. The syndrome can affect menstrual cycles, ovulation, skin and hair, metabolic health, mental health and pregnancy risk. ^[1]

In May 2026 a global consensus process introduced the name Polyendocrine Metabolic Ovarian Syndrome (PMOS). The international guideline now uses PMOS/PCOS terminology, while WHO's January 2026 fact sheet and much of the medical literature still use PCOS. The condition itself and the 2023 guideline recommendations did not change simply because the name changed. ^{[2] [3]}

Symptoms and warning signs

Symptoms vary widely. Common patterns include irregular or absent periods, difficulty conceiving, excess facial or body hair, acne or oily skin, and scalp hair thinning. Metabolic risk and psychological symptoms may be clinically important even when the reproductive or skin features are mild. ^{[1] [3]}

Diagnosis

WHO describes diagnosis using at least two of three domains after other causes are excluded: signs or biochemical evidence of androgen excess, irregular/absent ovulation or periods, and polycystic ovarian morphology on ultrasound. The international guideline refines these criteria by life stage and allows anti-Müllerian hormone (AMH) as an alternative to ultrasound for defining polycystic ovarian morphology in adults in appropriate settings. ^{[1] [3]}

Ovarian cysts are not required for diagnosis, and the “cysts” implied by the old name are not pathological cysts. Adolescents require particular care to avoid overdiagnosis because irregular cycles and acne can overlap with normal pubertal development. ^{[2] [3]}

Long-term health considerations

PCOS/PMOS is associated with insulin resistance, type 2 diabetes, adverse cardiovascular risk factors, sleep apnea and endometrial hyperplasia risk. Anxiety, depression, eating disorders and body-image distress are also important parts of care. The presence or absence of higher body weight does not define the condition. ^{[1] [3]}

Treatment and management

There is no single treatment for every patient. Healthy lifestyle behaviors are recommended for all, with goals centered on health and quality of life rather than weight alone. Treatment is then matched to the person's priorities: cycle regulation and endometrial protection, acne or hirsutism, metabolic risk, fertility, or psychological wellbeing. ^{[1] [3]}

Combined oral contraceptive pills are commonly used for cycle regulation and androgen-related symptoms when appropriate. Metformin may be used particularly for metabolic indications and in selected reproductive contexts. Fertility treatment is individualized; the international guideline supports evidence-based ovulation-induction approaches rather than assuming IVF is always first-line. ^[3]

Pregnancy considerations

People with PCOS/PMOS have higher rates of pregnancy complications including gestational diabetes and hypertensive disorders, so preconception risk assessment and appropriate antenatal monitoring can be important. Fertility treatment should be coordinated with broader metabolic and pregnancy health rather than treated as an isolated issue. ^{[1] [3]}

Sources

1. WHO — Polycystic ovary syndrome fact sheet, 22 January 2026
2. Monash University — Polyendocrine Metabolic Ovarian Syndrome: new name announced 13 May 2026
3. International PCOS/PMOS Network · Monash University — International Evidence-based Guideline for the Assessment and Management of PCOS/PMOS

This article is based on trusted medical sources and is awaiting clinician review. It is not a substitute for personalized medical advice.