The authors argue that given the uncertainties in the current evidence, the risk of psychological harm and the impacts of applying one-size-fits-all diagnostic criteria to an-often wide-ranging set of presenting symptoms, it is important not to rush into diagnosing women as having a lifelong condition with unknown benefit.

Furthermore, without clear data, the scientists say it may be better to treat those at risk of overdiagnosis symptomatically, such as adolescents, young women and those with the milder characteristics or phenotypes, rather than on the basis of a definition that has inadvertently led to likely over-diagnosis, overtreatment and harm.

Changing definitions

Polycystic ovary syndrome (PCOS) happens when a woman's ovaries or adrenal glands produce more male hormones than normal. PCOS is the most commonly diagnosed endocrine disorder in reproductive aged women, and is associated with an increased risk of diabetes, metabolic syndrome, heart disease, high blood pressure, and poorer psychological wellbeing.

It is considered a lifelong condition that has no cure, and includes a wide range of symptoms, such as irregular periods, polycystic appearing ovaries, hirsutism (excess hair) and acne.

First described in 1935, The National Institutes of Health (NIH) established two diagnostic criteria for PCOS in 1990. In 2003, at a meeting of experts in Rotterdam, sonographic presence of polycystic ovaries was added to the original NIH criteria. This change contributed to an increase in prevalence from about five percent to as many as 21 percent of women of reproductive age.

In 2006, experts recommended that clinical or biochemical evidence of hyperandrogenism was essential for the diagnosis to be made, as “the non-hyperandrogenic phenotypes do not have the same associated risks of long-term implications that are evident in the hyperandrogenic phenotypes.”

Problems of overdiagnosis

Symptoms tend to first appear during adolescence, and because the syndrome is linked toglucose intolerance and increased risk of type 2 diabetes, early diagnosis may help reduce long-term health issues, experts say.

But diagnosing PCOS in adolescence is challenging, according to Tessa Copp of the University of Sydney who is the leading author on the BMJ article.