PCOS – the condition that never was

Maisy looks disappointed. She has been struggling with acne, hirsutism, irregular periods, hyperglycaemia and dyslipidaemia. She’s been told it’s her weight and she needs to lose weight, but despite years of trying through strict diets and exercise, nothing has worked. 

She had an ultrasound scan. She was hoping for an explanation, validation. But the ultrasound was normal. Her ovaries are not polycystic.

Can someone have polycystic ovary syndrome when their ovaries are not polycystic? 

The truth is they can and they can’t, because PCOS is the condition that never was. 

What Maisy has is polyendocrine metabolic ovarian syndrome, or PMOS, the new international name for PCOS, a name which much better describes what is happening in the 170 million women worldwide affected by this condition.

Last week the Lancet published the global consensus process leading to this name change. It was originally called for in 2012 in recognition of the inaccuracy of the name PCOS. Clearly this implies, to medics and patients alike, that this is a condition of the ovaries. It was natural to assume the ovaries may be driving the myriad of issues associated with PCOS – back in 1935, the year widely cited for the ‘discovery’ of PCOS by two American gynaecologists, they observed in affected women ovaries with an enlarged, cystic appearance. Coupled with menstrual irregularity and infertility it all pointed towards the ovaries.

But over time our understanding of this condition has significantly evolved. Modern diagnostic criteria requires only 2 out 3 features from 1) oligo-anovulation, 2) clinical or biochemical hyperandrogenism, and/or 3) polycystic ovaries or raised anti-mullerian hormone. We can make a diagnosis with just irregular menstruation and hyperandrogenism alone; the presence of polycystic ovaries has not been required to diagnose PCOS for years.

As the new name indicates, PMOS is linked with multiple endocrine abnormalities which drive the complications our patients experience. 

Hyperandrogenism is caused by central neuroendocrine abnormalities such as elevated gonadotrophin-releasing hormone pulsatility leading to high luteinising hormone levels which in turn lead to high ovarian androgen production. Androgen levels are further elevated by insulin resistance, present in 85% of women with PMOS, including 75% of women with a BMI under 25, demonstrating that obesity is not a cause of PMOS but a consequence. There are many more endocrine abnormalities which drive metabolic dysfunction – dysfunctional sympathetic nervous systems, abnormal adipokine signalling, altered gut-hormone interactions, low-grade chronic inflammation, to name a few.

Radiological changes to the ovaries remain a diagnostic indicator, but as you and I know it was never true ‘cysts’ that were seen, rather immature ovarian follicles arrested in development linked to endocrine dysfunction affecting follicular maturation. Another consequence rather than cause. This knowledge and the subsequent name change may provide some reassurance for women who may naturally be concerned about having a condition resulting in ‘polycystic ovaries’. Sometimes we forget the impact such names can have. This disordered folliculogenesis raises AMH, although ordering this test on the NHS is likely to still be limited. 

The change in name has not come with any change to gold standard management, which was set out in international guidance in 2023. This remains a condition affecting metabolism, the reproductive system, skin and mental health. 

Arguably many women with PMOS are not getting optimally managed based on the latest knowledge and recommendations, a gap that needs addressing. Screening for hyperlipidaemia, impaired glucose tolerance, obstructive sleep apnoea and mental health issues should be routine, and consideration of the risk of endometrial hyperplasia. Discussion and education around lifestyles measures is important while avoiding weight stigma. The COCP can help manage hyperandrogenism and irregular cycles, metformin may improve weight, hormonal and metabolic outcomes, spironolactone can be considered for hirsutism. Women struggling with fertility should be referred early. New treatments, such as GLP1 receptor agonists, show promise. 

But perhaps the first step to addressing the gap is more simple: having an accurate name.