POMS (polyeendocrine metabolic ovarian syndrome): what it is, differences from PCOS, symptoms, insulin resistance and treatments

Why has the name changed from PCOS to PMOS?

The international change to PMOS stems from a global effort spanning years, involving medical societies and patient groups.

This name change is not merely intended to update a medical label we have been using for decades. Its aim is to get to the root of a historical problem with PCOS: having oversimplified a complex condition—both hormonal and metabolic— by presenting it as if it were solely an issue “of the ovary” or of what is seen on an ultrasound scan.

Reasons for using the terms PMOS:

• Terminological and diagnostic precision. The term “polycystic” can be misleading: not all patients have ovarian “cysts” in the clinical sense of the term.
• Recognition of the metabolic component as the central focus. It is a polyendocrine and metabolic disorder that may involve insulin resistance, an increased risk of glycaemic abnormalities, dyslipidaemia and long-term repercussions on cardiometabolic health, as well as skin manifestations and effects on general well-being.
• Better healthcare communication and reduced confusion. A more descriptive name makes it easier for patients and professionals to understand that the problem is not limited to an ultrasound image.

Variability and timing of onset

The symptoms of PMOS (polyenodocrine metabolic ovarian syndrome) can vary greatly between women: in some they appear from adolescence, whilst in others they are identified later, particularly when they begin trying to conceive.

Menstrual irregularities and ovulation

Irregular cycles, widely spaced periods, absence of menstruation for periods (amenorrhoea) or, sometimes, heavy or prolonged bleeding.

These are usually related to irregular ovulation or anovulation (absence of ovulation), which reduces the actual chances of pregnancy throughout the year.

When cycles are long or unpredictable, it is also more difficult to identify the fertile window.

Excess androgens (hyperandrogenism)

This can be detected through hormone testing and/or manifest clinically.

The most common symptoms are: hirsutism (hair on the face, chest, abdomen, back), acne and androgenetic alopecia.

“Polycystic” ovarian morphology on ultrasound

In some patients, multiple small follicles are observed. Traditionally, these were referred to as “cysts”, but in most cases they are follicles that have not completed their maturation and remain arrested without ovulating.

Therefore, diagnosis requires consideration of symptoms, medical history and female hormone profile, not just ultrasound.

Insulin resistance and metabolic abnormalities

Many patients present with insulin resistance, which can contribute to weight gain or make weight loss difficult and is associated with an increased risk of prediabetes/type 2 diabetes.

Furthermore, insulin resistance can contribute to hormonal imbalance and stimulate increased androgen production, exacerbating symptoms and further disrupting ovulation.

This is one of the reasons why the term PMOS includes “metabolic”, as the syndrome does not only affect the ovaries; it can have implications for overall health in the short, medium and long term.