Polycystic ovary syndrome (PCOS) affects an estimated 8%-13% of women, and yet “it has been quite a black box for many years,” as Margo Hudson, MD, an assistant professor of endocrinology, diabetes, and hypertension at Harvard Medical School, Boston, puts it. That black box encompasses not only uncertainty about the etiology and pathophysiology of the condition but even what constitutes a diagnosis.
Even the international guidelines on PCOS management endorsed by the American Society for Reproductive Medicine – a document developed over 15 months with the input of 37 medical organizations covering 71 countries – notes that PCOS diagnosis is “controversial and assessment and management are inconsistent.” The result, the guidelines note, is that “the needs of women with PCOS are not being adequately met.”
One of the earliest diagnostic criteria, defined in 1990 by the National Institutes of Health, required only hyperandrogenism and irregular menstruation. Then the 2003 Rotterdam Criteria added presence of polycystic ovaries on ultrasound as a third criterion. Then the Androgen Excess Society determined that PCOS required presence of hyperandrogenism with either polycystic ovaries or oligo/amenorrhea anovulation. Yet the Endocrine Society notes that excess androgen levels are seen in 60%-80% of those with PCOS, suggesting it’s not an essential requirement for diagnosis, leaving most to diagnose it in people who have two of the three key criteria. The only real agreement on diagnosis is the need to eliminate other potential diagnoses first, making PCOS always a diagnosis of exclusion.
Further, though PCOS is known as the leading cause of infertility in women, it is more than a reproductive condition, with metabolic and psychological features as well. Then there is the range of comorbidities, none of which occur in all patients with PCOS but all of which occur in a majority and which are themselves interrelated. Insulin resistance is a common feature, occurring in 50%-70% of people with PCOS. Accordingly, metabolic syndrome occurs in at least a third of people with PCOS and type 2 diabetes prevalence is higher in those with PCOS as well.
Obesity occurs in an estimated 80% of women with PCOS in the United States, though it affects only about 50% of women with PCOS outside the United States, and those with PCOS have an increased risk of hypertension. Mood disorders, particularly anxiety and depression but also, to a lesser extent, bipolar disorder and obsessive-compulsive disorder, are more likely in people with PCOS. And given that these comorbidities are all cardiovascular risk factors, it’s unsurprising that recent studies are finding those with PCOS to be at greater risk for cardiometabolic disease and major cardiovascular events.
“The reality is that PCOS is a heterogenous entity. It’s not one thing – it’s a syndrome,” Lubna Pal, MBBS, a professor of ob.gyn. and director of the PCOS Program at Yale University, New Haven, Conn., said in an interview. A whole host of factors are likely playing a role in the causes of PCOS, and those factors interact differently within different people. “We’re looking at things like lipid metabolism, fetal origins, the gut microbiome, genetics, epigenetics, and then dietary and environmental factors,” Nichole Tyson, MD, division chief of pediatric and adolescent gynecology and a clinical associate professor at Stanford (Calif.) Medicine Children’s Health, said in an interview. And most studies have identified associations that may or may not be causal. Take, for example, endocrine disruptors. BPA levels have been shown to be higher in women with PCOS than women without, but that correlation may or may not be related to the etiology of the condition.