Polycystic ovary syndrome (PCOS)

About PCOS

PCOS is a common hormonal condition. The WHO estimates it affects roughly 10–13% of women of reproductive age, and notes that a large proportion of people with PCOS are undiagnosed. A key feature for fertility is that ovulation can be irregular or infrequent, which makes timing conception harder. Signs vary a lot between people, and some have very mild features.

How it is diagnosed

Diagnosis uses the internationally recognised Rotterdam criteria: in adults, PCOS is diagnosed when at least two of three features are present — signs of excess androgen (clinical or on blood tests), irregular or absent ovulation, and a polycystic ovary appearance on ultrasound (or, per the 2023 international guideline, a raised AMH level as an alternative to ultrasound in adults) — after other conditions have been ruled out. Because features overlap with other issues, diagnosis is made carefully rather than from a single test.

Fertility and PCOS

The WHO describes PCOS as one of the most common causes of infertility related to ovulation. Having PCOS does not mean pregnancy is impossible: many people conceive, sometimes with support to encourage ovulation, and sometimes with treatments such as IUI or IVF. A clinician can explain the options that fit your situation.

Longer-term health

PCOS is also associated with longer-term health considerations, including type 2 diabetes, high blood pressure, cardiovascular disease, sleep apnoea, and changes to the womb lining. Because of this, care often looks beyond fertility alone.

When to seek help sooner: very heavy or prolonged bleeding, or severe pelvic pain, should be checked promptly by a clinician.