PCOS has a new name: What PMOS means for fertility, metabolic health, and clinical nutrition care

For decades, polycystic ovary syndrome, or PCOS, has been one of the most common yet most misunderstood hormone conditions affecting women with ovaries. Now, a major global effort published in The Lancet has introduced a new name: polyendocrine metabolic ovarian syndrome, or PMOS.

At WeNatal, we see this as more than a terminology update. It is a long-overdue shift in how we talk about hormone health, fertility, metabolic resilience, and whole-person care.

The previous name, “polycystic ovary syndrome,” made the condition sound like it was primarily about ovarian cysts. But PMOS is not simply an “ovary problem.” It is a complex, lifelong endocrine-metabolic condition that can affect ovulation, androgen levels, insulin sensitivity, blood sugar regulation, skin, weight regulation, cardiovascular risk, emotional wellbeing, and pregnancy outcomes.

That distinction matters, especially for anyone trying to conceive.

The Endocrine Society reports that PMOS affects about 1 in 8 women, or more than 170 million women worldwide, and that more than 50 patient and professional organizations participated in the renaming process. The name change followed 14 years of global collaboration, more than 22,000 survey responses, and a planned three-year transition, with full implementation expected in the 2028 International Guideline update.

What does PMOS stand for?

PMOS stands for polyendocrine metabolic ovarian syndrome.

Here’s what each part means:

Polyendocrine means multiple hormone systems are involved. PMOS can include androgen excess, ovulatory dysfunction, insulin resistance, and broader endocrine signaling changes.

Metabolic highlights the central role of insulin resistance, blood sugar regulation, lipid health, inflammation, body composition, and long-term cardiometabolic risk.

Ovarian acknowledges that ovulation, menstrual cycles, follicles, and fertility are still important, but they are not the whole story.

This new name better reflects what clinicians, researchers, and patients have known for years: PMOS is systemic. It can influence the entire reproductive-metabolic ecosystem.

Why was PCOS renamed?

PCOS was renamed because the old name was scientifically incomplete and clinically misleading.

The term “polycystic ovary syndrome” overemphasized ovarian appearance and implied that ovarian cysts were central to diagnosis. In reality, the “cysts” often discussed in PCOS are not abnormal cysts; they are small follicles. Some people with PCOS/PMOS do not have polycystic ovarian morphology at all, and ovarian cysts are not required for diagnosis. The World Health Organization notes that diagnosis can be made when at least two key features are present such as high androgen signs or levels, irregular or absent periods, and/or polycystic ovaries, after other causes are excluded.

The old name also contributed to a narrow care model. Too often, patients were told to “come back when you want to get pregnant,” given a birth control prescription, advised to lose weight, or left without a comprehensive metabolic, mental health, or fertility plan.

The new name pushes the conversation forward: PMOS is not just about periods. It is not just about ovaries. It is not just about weight. It is not just about fertility. It is a whole-body hormone and metabolic condition that deserves whole-person care.

Does the diagnosis change?

For now, the name is changing more than the diagnostic framework.

Clinically, PMOS diagnosis still generally reflects the same core features historically used for PCOS: irregular ovulation or irregular cycles, clinical or biochemical signs of androgen excess, and/or polycystic ovarian morphology, after ruling out other conditions. The WHO emphasizes that some women with PCOS do not have polycystic ovaries and that ovarian cysts are not required for diagnosis.

The 2023 International Evidence-Based Guideline also recognizes that PCOS is heterogeneous, with reproductive, metabolic, and psychological features, and emphasizes improved education, shared decision-making, and patient-centered care.

In other words: the name change may not mean that everyone needs to be re-diagnosed. But it should change how clinicians explain, screen, and support the condition.

What PMOS means for fertility

PMOS is one of the most common causes of irregular ovulation and infertility. The WHO describes PCOS as the most common cause of anovulation globally and a leading cause of infertility.

From a fertility perspective, PMOS may affect:

• Ovulation regularity
• Cycle predictability
• Egg maturation and follicle development
• Androgen balance
• Insulin sensitivity
• Inflammatory tone
• Endometrial health
• Pregnancy risks, including gestational diabetes and hypertensive disorders

For those trying to conceive, this is why PMOS care should not begin and end with cycle tracking. It should include metabolic assessment, nutrition, micronutrient adequacy, sleep, movement, stress physiology, gut health, medication coordination when needed, and preconception planning.

At WeNatal, we believe fertility is not only about the ovaries. It is also about the environment in which eggs mature, hormones communicate, blood sugar is regulated, and implantation and pregnancy unfold.

What PMOS means for metabolic health

The “M” in PMOS may be the most clinically important part of the new name.

PCOS has long been associated with insulin resistance, impaired glucose tolerance, type 2 diabetes risk, lipid changes, blood pressure concerns, sleep apnea, and cardiovascular risk. The WHO describes PCOS as a chronic metabolic condition associated with increased long-term risk for insulin resistance, type 2 diabetes, and obesity.

The 2023 International Evidence-Based Guideline recommends that glycemic status be assessed at diagnosis in all adults and adolescents with PCOS, and reassessed every one to three years based on individual diabetes risk factors. 

This is a major clinical point: metabolic risk can be present even in someone who does not “look insulin resistant.” PMOS can occur across body sizes, and insulin resistance cannot be ruled out by weight alone.

The WeNatal perspective: PMOS is a fertility and metabolic health signal

At WeNatal, we view the renaming from PCOS to PMOS as a more accurate, compassionate, and clinically useful framework.

For women preparing for pregnancy, PMOS is not simply a diagnosis to “manage.” It is a signal to support the systems that matter most for reproductive health: blood sugar stability, hormone signaling, mitochondrial function, inflammation balance, nutrient sufficiency, ovulatory health, and resilience before conception.

This is especially important because preconception health is not a one-cycle project. Egg maturation takes months. Metabolic patterns influence hormonal patterns. Nutrient status affects reproductive physiology. And pregnancy places new demands on glucose regulation, thyroid function, cardiovascular health, and micronutrient reserves.

PMOS gives us a better language for what many women have experienced all along: fertility symptoms are often metabolic symptoms, and metabolic symptoms are often hormone symptoms.

What this means clinically for nutrition teams

For nutrition professionals working with clients in clinical or private practice, the PMOS name change should shift care from a narrow “cycle and weight” model to a reproductive-metabolic care model.

Screen beyond the period tracker

A client with irregular cycles, acne, hair changes, infertility, recurrent pregnancy loss, high fasting insulin, elevated androgens, or a history of gestational diabetes risk deserves a broader clinical lens.

Nutrition teams should consider intake questions around:

• Cycle length, ovulation signs, and bleeding patterns
• Acne, hirsutism, hair thinning, and oily skin
• Blood sugar symptoms such as cravings, shakiness, fatigue after meals, or night waking
• Personal or family history of type 2 diabetes, gestational diabetes, hypertension, or dyslipidemia
• Sleep quality, snoring, daytime fatigue, and symptoms of sleep apnea
• Mental health, body image, disordered eating history, and stress load
• Fertility goals and timeline
• Pregnancy history, including miscarriage, gestational diabetes, preeclampsia, or hypertensive disorders

This is not about diagnosing PMOS as a nutrition team unless that is within the clinician’s scope. It is about identifying patterns, making appropriate referrals, and coordinating care.

Treat insulin resistance as a core clinical consideration

The PMOS name makes insulin resistance harder to overlook.

In practice, this means nutrition care should prioritize blood sugar stability without pushing overly restrictive diets. The goal is not “low carb at all costs.” The goal is metabolic flexibility, adequate nourishment, and sustainable glucose regulation.

Helpful clinical nutrition strategies may include:

• Protein-forward meals, especially at breakfast
• High-fiber carbohydrates chosen and timed strategically
• Pairing carbohydrates with protein, fat, and fiber
• Reducing ultra-processed carbohydrates and added sugars
• Encouraging post-meal walks or gentle movement
• Supporting muscle mass through resistance training
• Avoiding long fasts when they worsen cravings, sleep, cortisol patterns, or binge-restrict cycles
• Using CGM data thoughtfully when available, without creating food fear

The 2023 guideline notes that lifestyle intervention like exercise or multicomponent diet plus exercise and behavioral strategies, should be recommended for all women with PCOS to improve metabolic health, including central adiposity and lipid profile. It also emphasizes that lifestyle goals should be co-developed with the patient and that benefits exist regardless of weight loss.

Personalize nutrition instead of prescribing a single “PCOS diet”

There is no one universal PMOS diet. For clinical nutrition teams, this means the best plan is the one that is evidence-informed, nutrient-dense, culturally appropriate, metabolically supportive, and sustainable.

A strong PMOS nutrition framework may include:

• 25–35 grams of protein per meal, individualized to body size and goals
• 25–35+ grams of fiber per day as tolerated
• Omega-3-rich foods such as low-mercury fatty fish, chia, flax, and walnuts
• Colorful plants for polyphenols and antioxidant support
• Magnesium-rich foods such as pumpkin seeds, leafy greens, cacao, legumes, and nuts
• Adequate choline, iodine, selenium, zinc, folate, B12, vitamin D, and iron based on diet pattern and labs
• Carbohydrate timing around activity or earlier in the day if helpful for glucose
• Regular meals when under-eating, over-fasting, or stress physiology is contributing to symptoms
• Strategic supplementation when clinically indicated

Build a preconception lab and referral pathway

Because PMOS affects fertility, pregnancy risk, and long-term health, nutrition teams should have a clear referral and lab coordination workflow.

Consider advocating for assessment of:

• A1c, fasting glucose, fasting insulin, and/or 75-gram OGTT
• Lipid panel, ApoB when appropriate
• Blood pressure
• Thyroid markers, including TSH and thyroid antibodies when clinically relevant
• Vitamin D
• Ferritin and iron studies
• B12 and folate status, especially for vegetarian/vegan clients or metformin users
• Androgens such as total/free testosterone, DHEA-S, SHBG
• Prolactin and 17-OHP when differential diagnosis is relevant
• hs-CRP or other inflammatory markers when clinically indicated

The 2023 guideline recommends blood pressure measurement annually and when planning pregnancy or fertility treatment, and recommends OGTT consideration when planning pregnancy or seeking fertility treatment because of pregnancy-related hyperglycemia risks.

Frequently asked questions about PCOS, PMOS, and fertility

What is the new name for PCOS?

The new name for PCOS is PMOS, which stands for polyendocrine metabolic ovarian syndrome. The name was chosen to better reflect that the condition affects multiple hormone systems, metabolic health, reproductive function, skin, mental health, and long-term health—not just the ovaries.

Why did PCOS get renamed?

PCOS was renamed because “polycystic ovary syndrome” was misleading. The condition is not defined by abnormal ovarian cysts, and many people with PCOS do not have polycystic ovaries. The new name highlights the endocrine and metabolic nature of the condition.

Is PMOS different from PCOS?

PMOS is the new name for PCOS. The name is changing to better reflect the condition, but the diagnostic transition will take time. The Endocrine Society notes that full implementation is expected in the 2028 International Guideline update.

Do you need ovarian cysts to have PMOS?

No. Ovarian cysts are not required for diagnosis. The WHO states that some women with PCOS do not have polycystic ovaries and that ovarian cysts are not required for diagnosis.

How does PMOS affect fertility?

PMOS can affect fertility by disrupting ovulation, menstrual cycle regularity, androgen balance, insulin sensitivity, and metabolic health. PCOS/PMOS is one of the most common causes of anovulation and a leading cause of infertility globally.

What is the best diet for PMOS?

Evidence-based guidance recommends sustainable healthy eating tailored to the individual’s preferences, goals, metabolic markers, and clinical needs. The best approach is typically protein-forward, fiber-rich, blood-sugar supportive, nutrient-dense, anti-inflammatory, and realistic long term.

Can PMOS be treated naturally?

Lifestyle and nutrition strategies can play an important role in PMOS care, especially for blood sugar regulation, metabolic health, and fertility preparation. However, PMOS often benefits from a team-based approach that may include nutrition, movement, sleep support, stress care, medical evaluation, medications, and fertility treatment when needed.

A note from WeNatal on evolving science and better support

The shift from PCOS to PMOS reflects something we have believed at WeNatal from the beginning: fertility is not separate from whole-body health. It is connected to your hormones, metabolism, blood sugar balance, inflammation balance, nutrient status, sleep, stress, environment, and long-term wellbeing.

This evolving language matters because it gives people a more accurate and compassionate framework for understanding their bodies. PCOS was never just about ovarian “cysts,” and fertility was never just about the ovaries. The new PMOS framework helps validate what so many people have experienced firsthand: reproductive health is deeply connected to metabolic and endocrine health.

At WeNatal, our mission has always been to support fertility proactively, before pregnancy begins, and to help both partners build a stronger foundation for conception, pregnancy, and beyond. That starts with education, clinical experts, better conversations, and comprehensive nutrition support.

Wherever you are in your fertility journey, you deserve more than a reactive approach. You deserve support that looks at the full picture.

WeNatal for Her was thoughtfully formulated to help support preconception and pregnancy nutrient needs, including key nutrients like methylated folate, choline, iodine, selenium, vitamin D, and B vitamins. Omega DHA+ offers targeted omega-3 support with DHA and EPA, nutrients that play important roles in reproductive, pregnancy, and overall health.

The science is evolving, and so is the standard of care. WeNatal is here to help you feel informed, supported, and nourished every step of the way.