From PCOS to PMOS: More Than an Ovarian Condition

Why change a name that has been used for decades?

One problem with “polycystic ovary syndrome” is that it gives a misleading impression of what the condition actually is. Despite the name, women with PCOS do not necessarily have ovarian cysts at all. The characteristic appearance on an ultrasound is actually caused by an increased number of small ovarian follicles. More importantly, focusing on the ovaries fails to capture the much wider hormonal and metabolic features of the condition.

The new name—polyendocrine metabolic ovarian syndrome—recognises that this is a condition involving several interacting hormone systems, metabolism and ovarian function, rather than simply a problem with the ovaries.

How is PMOS diagnosed?

The name has changed, but the core diagnostic approach remains familiar.

In adults, diagnosis generally requires two out of three features, after other possible causes have been excluded.

• The first is higher-than-usual androgen activity. Androgens such as testosterone are sometimes described as “male hormones”, although women naturally produce them too. Higher levels or increased androgen activity can cause symptoms such as increased facial or body hair, acne or scalp hair thinning. In some women it is identified through blood tests rather than obvious physical symptoms.

• The second is irregular or absent ovulation. This often shows up as periods that are infrequent, very irregular or absent altogether.
  The third is an increased number of small follicles in the ovaries. These can produce the characteristic appearance seen on an ultrasound scan. They are follicles containing immature eggs—not ovarian cysts in the usual medical sense. In adults, anti-Müllerian hormone (AMH) can now sometimes be used instead of ultrasound to identify this feature.

Not everyone with PMOS therefore looks the same. A woman can meet the diagnostic criteria without having the characteristic ovarian appearance, and she does not need to have all three features.

Could PMOS once have been an advantage?

One intriguing theory about PMOS asks us to look much further back in human history.

For most of human evolution, food was not continuously available. Periods of relative abundance were interspersed with periods of scarcity. Researchers have proposed that some of the characteristics we now associate with PMOS may have offered advantages in that very different environment.

Insulin resistance, for example, helps maintain glucose in the bloodstream, while an increased tendency to store energy as fat could provide reserves during periods when food was scarce. Reduced fertility during times of nutritional stress could also potentially conserve the considerable energy required for pregnancy and breastfeeding until conditions became more favourable.

This has led some researchers to describe women carrying these characteristics as part of a historical “metabolic elite”—particularly well adapted to surviving unpredictable food availability.

It is an intriguing idea rather than an established explanation for PMOS. Nevertheless, evolutionary models propose that insulin resistance, increased energy storage, higher androgen activity and reduced fertility could all have offered survival advantages in ancestral environments.

An ancient advantage in a modern environment?

The difficulty is that our environment has changed far more quickly than our biology.

For many people today, energy-dense food is continuously available while everyday life requires much less physical activity.

Characteristics that might once have protected against starvation can therefore become disadvantageous.

Insulin resistance is particularly important in PMOS. The body becomes less responsive to insulin and compensates by producing more of it. Over time, this contributes to an increased risk of impaired glucose regulation and type 2 diabetes.

Excess weight—particularly around the abdomen—can make insulin resistance worse, although it is important to recognise that PMOS occurs in women across the weight spectrum. Women with PMOS also have higher rates of cardiovascular risk factors, including high blood pressure and abnormal cholesterol levels, and may have an increased risk of cardiovascular disease.

This is one reason why the word “metabolic” in the new name matters. It shifts attention beyond periods, fertility and the ovaries towards long-term health.

Management should be individualised. Healthy eating, regular physical activity, sleep and other sustainable lifestyle measures can improve metabolic health even without weight loss, while preventing excess weight gain or supporting weight management may be helpful where appropriate. Metformin may be considered, particularly where metabolic features are present. Blood pressure, cholesterol and glucose regulation should also be assessed and monitored according to individual risk.

What does PMOS have to do with ADHD?

There is another intriguing connection that receives much less attention: ADHD.

Several large population studies have found that children born to mothers with PCOS are more likely to be diagnosed with ADHD. A meta-analysis combining the available studies found an approximately 40% higher relative risk of ADHD among children whose mothers had PCOS.

We don't yet know why.

Researchers have considered several possibilities, including shared genetic factors, differences in the hormonal environment during pregnancy and metabolic factors such as insulin resistance.

There is also some preliminary evidence that ADHD symptoms may be more common in women with PMOS themselves. In one small study of 40 women with PCOS and 40 women without the condition, women with PCOS reported more current and childhood ADHD symptoms. Larger studies using formal ADHD diagnostic assessments are needed.

This raises another possible explanation for the association between maternal PMOS and ADHD in children. ADHD in women has historically been under-recognised. If ADHD is more common among women with PMOS than we currently recognise, some of the association seen in their children could reflect shared genetic susceptibility, rather than—or in addition to—the hormonal and metabolic environment during pregnancy.

At present, we simply don't know. But it is another reason why looking beyond the ovaries—and considering women's metabolic, hormonal and mental health together—may prove important.

Looking beyond the ovaries...

Perhaps that is the most important message behind the change from PCOS to PMOS.

This is not simply a condition of the ovaries, and it is not simply a fertility problem. It involves interconnected reproductive, hormonal and metabolic systems, with implications for health across a woman's life.

The evolutionary story offers one possible explanation for why characteristics that may once have helped humans survive can create difficulties in a very different modern environment. And emerging research into ADHD reminds us that there may still be aspects of PMOS that we do not fully understand.

Changing the name does not change the condition. But changing the way we think about it may help us ask better questions about women's health.

If you would like to discuss any concerns about your hormonal health including worries about PMOS the click below to book a consultation with one of our clinicians.