From PCOS to PMOS: A Meaningful Renaming
The condition formerly known as Polycystic Ovary Syndrome (PCOS) has been officially renamed Polyendocrine Metabolic Ovarian Syndrome (PMOS). The name change was announced on May 12, 2026, at the European Congress of Endocrinology in Prague and published in The Lancet.
Dr Veronique Viardot-Foucault, director of clinical endocrinology at the Department of Reproductive Medicine at KK Women's and Children's Hospital, noted that the idea of renaming PCOS was first raised in 1995 and revisited in 2012, but previously failed due to lack of global leadership, consensus on an alternative name, and patient engagement. This successful change resulted from 14 years of collaboration between international societies and patient groups across six continents, driven largely by patients themselves.
Patients often described the old name PCOS as confusing, misleading, and overly focused on fertility. For instance, a woman seeking help for increased body hair or irregular periods might be diagnosed with PCOS, a term suggesting polycystic ovaries that may not match her experience. Treatment was also often viewed through a fertility lens, even if having children was not her primary concern at diagnosis.
What is PMOS? A More Accurate Medical Definition
“Medically, PMOS is now understood as a complex, lifelong condition influenced by genetic, developmental, metabolic, and environmental factors,” said Dr Viardot-Foucault. “It affects multiple hormone systems, including reproductive hormones, insulin regulation and brain-hormone signaling, with wide-ranging effects on metabolism, skin, mental health, and overall well-being.”
Dr Clara Ong, obstetrician and gynecologist at Parkway MediCentre, explained that the term 'polyendocrine' acknowledges the condition isn't just an issue with hormones produced in the ovaries (mainly estrogen and progesterone) but involves other hormones throughout the body. And 'metabolic' explicitly shows that insulin resistance, risk of diabetes, cholesterol issues, and cardiovascular health are core features of the condition.
Previously, the condition was often grouped under fertility rather than as a chronic metabolic disease. The new name shifts the focus from gynecological connotations to a more comprehensive care model. Dr Viardot-Foucault emphasized that a coordinated, multidisciplinary approach involving primary care practitioners, endocrinologists, gynecologists, dermatologists, dietitians, and mental health professionals is critical.
Diagnosis Criteria for PMOS
The first step in diagnosing PMOS is to order blood tests to rule out similar conditions such as thyroid dysfunction and pituitary disorders. Next, diagnosis is confirmed via blood tests for testosterone and anti-mullerian hormone (AMH), along with a possible pelvic ultrasound. Further blood tests are then ordered to screen for possible complications or associations like insulin resistance.
A woman is diagnosed with PMOS if she has at least two of the following three main findings:
- Irregular, infrequent menstrual periods or no periods at all.
- Increase in facial or body hair, and/or blood tests showing high testosterone levels.
- An ultrasound scan showing multiple small cysts in at least one ovary, or a blood test showing elevated AMH levels (a marker of ovarian reserve; an unusually high result may suggest PCOS).
The Key Role of Insulin in PMOS
Dr Clara Ong stated that up to 70% of women with PMOS are insulin resistant. This often leads to higher insulin levels in the body, making it harder to maintain normal blood glucose levels. Therefore, PMOS patients have an increased risk of developing diabetes. Additionally, excess insulin damages blood vessels and causes chronic inflammation.
“Excess insulin may also cause some women with PMOS to be overweight or obese, particularly in the belly,” Dr Ong added. “This abdominal fat (visceral fat) can cause higher 'bad' cholesterol and decrease 'good' cholesterol. All these factors lead to an increased risk of high blood pressure and heart disease.”
Dr Viardot-Foucault stressed that women with PMOS who are not overweight should also be screened, as around 20 to 30% of lean women with the condition also have insulin resistance. Women with PMOS also have a higher risk of developing metabolic complications such as gestational diabetes and preeclampsia during pregnancy and need close monitoring. “If a pregnant woman develops high blood pressure or diabetes, her baby is more likely to have growth problems, be born early, have an unusually high or low birth weight, or experience low blood sugar after delivery,” she added.