Features and diagnosis of polycystic ovary syndrome
Polycystic ovary syndrome (PCOS) is a reproductive and metabolic disorder affecting females of reproductive age (in this topic, female is used to mean anyone presumed female at birth). PCOS affects 8 to 13% of females of reproductive age; the prevalence appears to be higher in Aboriginal and Torres Strait Islander peoples.
Consider the possibility of PCOS in females presenting with menstrual disturbance, hirsutism or premenopausal alopecia. Acne is less strongly associated with PCOS, but PCOS should be considered if hirsutism, alopecia, menstrual disturbance or obesity are also present. Before confirming a diagnosis of PCOS, exclude other causes of presenting features.
A diagnosis is made if an adult meets two of the following diagnostic criteria and other causes have been excluded:
- menstrual disturbance, including secondary oligomenorrhoea or amenorrhoea
- clinical or biochemical hyperandrogenism
- polycystic appearance of ovaries on ultrasound.
Additional features of PCOS (which are not essential for diagnosis) include:
- obesity
- insulin resistance (with a tendency to develop type 2 diabetes)
- subfertility
An ultrasound scan is not required for the diagnosis of PCOS if an adult has both menstrual disturbance and clinical or biochemical hyperandrogenism. If only one of these features is present, a transvaginal ultrasound should be performed in the first half of the menstrual cycle, and a follicle count should be requested1.
Refer adolescents with suspected PCOS for specialist assessment because interpretation of clinical features and ultrasound findings in adolescence is complex. Menstrual irregularity is only considered abnormal if it persists for more than 2 years post menarche. Normal adolescent ovaries may have a polycystic appearance for up to 8 years, so ultrasound is not recommended.