PCOS Is Now PMOS: Everything You Need to Know About Polyendocrine Metabolic Ovarian Syndrome

Polyendocrine Metabolic Ovarian Syndrome (PMOS), formerly known as Polycystic Ovary Syndrome (PCOS), is a complex, multisystem hormonal condition affecting 1 in 8 women worldwide. On 12 May 2026, a landmark global consensus published in The Lancet officially renamed the condition to better reflect its true biological nature — marking one of the most significant shifts in women’s health in decades.

What Is PMOS?

On 12 May 2026, a condition known to millions of women around the world received a new name. Polycystic Ovary Syndrome (PCOS) is now officially called Polyendocrine Metabolic Ovarian Syndrome (PMOS), following the publication of a landmark consensus study in The Lancet and its simultaneous presentation at the European Congress of Endocrinology in Prague.

This is far more than a semantic update. For decades, the term “polycystic ovary” created a fundamental misunderstanding: it reduced a complex, multisystem condition to a misleading image of ovarian cysts. In reality, many women with this condition do not have pathological ovarian cysts at all. The old name contributed to delayed diagnoses, fragmented care, stigma, and missed opportunities for early treatment — particularly around metabolic and cardiovascular risks.

The new name addresses all of this. Each word carries scientific intent:

• Polyendocrine: Recognises that the condition stems from multiple interacting hormonal disturbances, including insulin, androgens, and neuroendocrine hormones, rather than representing an isolated ovarian disorder.
• Metabolic: Acknowledges that insulin resistance, weight changes, increased risk of Type 2 diabetes and cardiovascular disease are inherent features of the syndrome, not secondary complications.
• Ovarian: Retains the connection to ovarian dysfunction and ovulatory disturbances, which remain defining features of the condition and are central to its impact on fertility.

PCOS vs. PMOS: What Actually Changed?

The condition itself has not changed. The science behind it has not changed. What changed is how we name, define, and ultimately understand it.

The old name placed the entire focus on ovaries and cysts — a framing that left the broader picture invisible to both patients and, in many cases, clinicians. The new name repositions PMOS as the multisystem endocrine-metabolic disorder it has always been.

This shift matters in practice. Women who were previously told “you don’t have cysts, so it may not be PCOS” may have been among the estimated 70% of individuals with the condition who remain undiagnosed worldwide. A name that more accurately reflects the biology of the condition is expected to improve recognition at every level — from patient self-awareness to clinical screening.

Why Was the Name Changed? A 14-Year Global Effort

The renaming of PCOS to PMOS is the result of one of the most extensive medical consensus processes ever undertaken for a single condition.

Led by Professor Helena Teede of Monash University in Australia, the process spanned 14 years and engaged stakeholders from every corner of the world. The scale and rigour of this effort set it apart:

• More than 22,000 people contributed across iterative global surveys, including patients, clinicians, researchers, and patient advocacy representatives from all world regions.
• 56 leading academic, clinical, and patient organisations were formally involved in the governance of the process.
• The final survey, conducted in 2025, received responses from nearly 15,000 participants.
• Online workshops held in November 2025 and February 2026 brought together experts globally to test and refine candidate names against criteria including scientific accuracy, cultural appropriateness, stigma avoidance, and clarity.
• The final name was selected in February 2026, with 87 out of 90 voting participants supporting PMOS immediately — the remaining participant subsequently agreed before the manuscript was submitted.
• The findings were published in The Lancet on 12 May 2026.

The principles that guided the name selection were clear: patient benefit, scientific accuracy, ease of communication, avoidance of stigma, and cultural appropriateness across different languages and healthcare systems. PMOS met all of them.

Professor Teede described the result as the largest initiative to rename a medical condition in history. The implications reach beyond terminology — advocates argue that accurately framing PMOS as a multisystem endocrine-metabolic disorder will open new avenues for research funding, clinical training, and policy reform that were previously constrained by the narrow lens of the old name.

Symptoms of PMOS: What to Look For

The symptoms of PMOS are identical to those previously associated with PCOS. What changes is the context in which they are understood and investigated.

Women with PMOS may experience:

• Irregular or infrequent menstrual cycles
• Absent or disrupted ovulation
• Excess androgen activity — presenting as unwanted hair growth (hirsutism), acne, or hair thinning on the scalp
• Insulin resistance, often associated with weight gain or difficulty losing weight
• Persistent fatigue and low energy
• Mood changes, anxiety, or low mood
• Difficulty conceiving

These symptoms may appear together or in isolation, and their severity varies considerably between individuals. For diagnosis, the Rotterdam criteria remain in use: at least two of the three key features — ovulatory dysfunction, clinical or biochemical signs of excess androgens, and polycystic ovarian morphology on ultrasound — must be present, with other causes excluded.

It is important to note that a polycystic appearance on ultrasound alone is not sufficient for a PMOS diagnosis, and the absence of visible follicles does not rule it out.

PMOS and Fertility: What Does This Mean for Your IVF Journey?

PMOS is one of the most common causes of ovulatory infertility in women of reproductive age. However, a diagnosis of PMOS does not mean that pregnancy is out of reach — for the vast majority of women, it means that the path to parenthood may benefit from targeted support and specialist guidance.

Understanding how PMOS affects fertility helps clarify what to expect and what options are available:

Ovulatory dysfunction: In PMOS, eggs may stall partway through the maturation process rather than completing a full cycle. When regular ovulation does not occur, identifying fertile windows becomes difficult and the likelihood of natural conception decreases.

Androgen environment and egg quality: Elevated androgen levels within the ovarian environment can create conditions that are less than ideal for developing eggs. This may affect egg quality and, consequently, the potential for successful fertilisation and early embryo development.

Endometrial receptivity: Irregular ovulatory cycles can also affect how well the uterine lining prepares for implantation. Without a consistently timed hormonal cycle, the endometrium may not reach optimal thickness or receptivity at the right moment.

Pregnancy considerations: Women with PMOS carry a modestly elevated risk of early miscarriage, gestational hypertension, and gestational diabetes. This makes careful monitoring throughout pregnancy particularly important.

Despite these challenges, PMOS is among the most treatable causes of infertility. Lifestyle modifications, ovulation induction medications, intrauterine insemination (IUI), and in vitro fertilisation (IVF) are all established pathways — and many women with PMOS respond well to ovarian stimulation, given that ovarian reserve is often well-preserved in this condition.

At Bahçeci, our specialists assess each patient’s complete hormonal, metabolic, and reproductive profile before recommending a treatment pathway. There is no single approach that fits every woman with PMOS, and a personalised plan remains the most effective starting point.

Already Diagnosed With PCOS? Here Is What You Should Do

If you have previously received a PCOS diagnosis, no immediate action is required on your part. Your diagnosis is valid and directly corresponds to the new PMOS terminology — the condition is the same, and your existing treatment or monitoring plan remains fully applicable.

What this change may mean for you in practical terms:

• Your medical records may continue to use the term PCOS during the transition period. This is expected and does not affect the accuracy of your diagnosis or the care you receive.
• If you have been managing symptoms with lifestyle changes, medication, or hormonal treatment, none of that changes as a result of the renaming.
• If you have been trying to conceive, or are planning to in the future, this is a good moment to revisit your assessment with a specialist. The broader understanding that comes with the PMOS framework — particularly around insulin resistance and metabolic health — may open new conversations about optimising your overall condition before or during fertility treatment.

If you have been experiencing symptoms but have not yet received a formal diagnosis, the wider recognition that PMOS brings may make it easier to be correctly identified and referred to the right specialist care.

The Transition: What to Expect Over the Next Three Years

The official renaming of PCOS to PMOS has been announced, but the transition to universal adoption will take time. A structured three-year implementation roadmap is already underway, with full integration planned for the 2028 update of the International Guideline — a document currently used across 195 countries.

Key milestones in the transition include:

• Development of multilingual patient and clinician education materials
• Integration of the PMOS terminology into electronic health records, medical textbooks, and health information systems worldwide
• A global communication strategy involving professional society toolkits and medical education programmes
• Formal incorporation into international disease classification systems, including ongoing engagement with the World Health Organization regarding ICD coding updates

During this period, you may encounter both PCOS and PMOS used interchangeably in clinical settings, on health platforms, and in conversations with healthcare providers. Both terms refer to the same condition. The transition is gradual by design — to allow clinicians, researchers, patient organisations, and health systems the time needed to align without disruption to patient care.

Frequently Asked Questions

Is PMOS the same condition as PCOS? 

Yes. The condition itself has not changed. Only the name and the framework used to describe it have been updated. A previous PCOS diagnosis is entirely equivalent to a PMOS diagnosis.

I was diagnosed with PCOS. Do I need to do anything? 

No immediate action is needed. Your diagnosis remains valid, and your current treatment or monitoring plan continues unchanged. If you have questions about how the new terminology applies to your specific situation, your specialist can provide guidance.

Can women with PMOS get pregnant? 

Yes. PMOS is a treatable cause of infertility, and many women with the condition conceive naturally or with medical support. The most appropriate approach depends on individual circumstances, including the severity of ovulatory dysfunction, ovarian reserve, and overall metabolic health.

Does PMOS affect the success of IVF treatment? 

Women with PMOS often have a well-preserved ovarian reserve, which can be an advantage in IVF stimulation protocols. However, careful monitoring is essential to minimise the risk of ovarian hyperstimulation syndrome (OHSS), which occurs at a higher rate in this group. A specialist familiar with PMOS will tailor the stimulation protocol accordingly.

How is PMOS diagnosed? 

The Rotterdam criteria remain the standard diagnostic framework. A diagnosis requires at least two of the following three features: ovulatory dysfunction, clinical or biochemical evidence of excess androgens, and polycystic ovarian morphology on ultrasound — with other causes ruled out. Adolescents require the first two criteria to reduce the risk of overdiagnosis.