Polycystic ovary syndrome (PCOS), one of the most common hormonal disorders affecting women of reproductive age, has officially been renamed Polyendocrine Metabolic Ovarian Syndrome (PMOS) following an international consensus published in The Lancet.
This new terminology reflects a more accurate understanding of the condition. Rather than being solely an ovarian disorder, PMOS is now recognized as a complex systemic disease involving endocrine, metabolic, reproductive and inflammatory pathways.
Importantly, this change does not modify the diagnostic criteria or current treatment recommendations. Instead, it aims to improve awareness, facilitate earlier diagnosis, and better reflect the multisystem nature of the disorder.
Why has the name changed?
For decades, the term polycystic ovary syndrome has been considered misleading.
The condition is not caused by ovarian cysts. Instead, ultrasound typically reveals multiple small follicles whose development has been arrested. Referring to these follicles as “cysts” has contributed to misunderstanding among both patients and healthcare professionals.
The previous name also underestimated the condition’s metabolic and endocrine components, often suggesting it was solely a gynecological disorder.
The new name—Polyendocrine Metabolic Ovarian Syndrome—highlights its complex hormonal and metabolic origins while recognizing its effects throughout the body.
The condition affects an estimated 170 million women worldwide, with approximately one in eight women living with the syndrome. However, around 70% remain undiagnosed.
Do the diagnostic criteria change?
No. The international consensus confirms that the current diagnostic criteria remain unchanged.
Women aged 20 years and older must meet at least two of the following criteria:
- Oligo-ovulation or irregular ovulation
- Clinical or biochemical hyperandrogenism
- Polycystic ovarian morphology on ultrasound or elevated Anti-Müllerian Hormone (AMH)
For adolescents aged 10–19 years, diagnosis requires both ovulatory dysfunction and hyperandrogenism.
Why is PMOS considered a systemic disease?
The new terminology reflects the multiple biological mechanisms involved in the condition.
Neuroendocrine dysfunction
Alterations in GnRH and LH secretion, changes in the LH/FSH ratio, and abnormalities involving dopamine, serotonin and GABA contribute to hormonal dysregulation.
Insulin resistance
Approximately 85% of women with PMOS present some degree of insulin resistance. Elevated insulin levels stimulate ovarian androgen production, contributing to hormonal imbalance.
Ovarian hyperandrogenism
Insulin resistance promotes increased androgen production by ovarian theca cells while reducing hepatic production of Sex Hormone-Binding Globulin (SHBG), leading to higher circulating androgen levels.
This hormonal imbalance contributes to visceral fat accumulation, chronic inflammation and worsening insulin resistance, creating a self-perpetuating cycle.
Follicular dysfunction
Excess androgen levels interfere with normal follicular development, leading to arrested follicles, elevated AMH levels and, in some cases, reduced oocyte quality.
Health consequences beyond fertility
PMOS is associated with several long-term health risks, including:
- Central obesity
- Insulin resistance
- Prediabetes and type 2 diabetes
- Non-alcoholic fatty liver disease
- Dyslipidemia
- Hypertension
- Cardiovascular disease
- Obstructive sleep apnea
Other commonly affected systems include:
- Reproductive: irregular menstrual cycles, infertility, pregnancy complications and increased risk of endometrial cancer.
- Dermatological: acne, hirsutism and androgenic alopecia.
- Psychological: anxiety, depression, eating disorders and reduced quality of life.
- Inflammatory: chronic low-grade inflammation and oxidative stress.
- Gut-endocrine axis: intestinal dysbiosis and altered incretin function.
- Autonomic nervous system: increased sympathetic activity, chronic stress and sleep disturbances.
What does this mean for fertility?
PMOS remains one of the leading causes of ovulatory infertility.
Irregular or absent ovulation may reduce the chances of natural conception. Additionally, insulin resistance, hyperandrogenism and chronic inflammation can negatively affect ovarian function, oocyte quality and the hormonal environment necessary for pregnancy.
For women trying to conceive, individualized assessment is essential. A comprehensive fertility evaluation should include hormonal, metabolic and reproductive factors to develop the most appropriate treatment strategy.
A more accurate understanding of the condition
The adoption of the name Polyendocrine Metabolic Ovarian Syndrome represents a significant step forward in understanding this complex disorder.
Rather than focusing exclusively on the ovaries, the new terminology acknowledges PMOS as a chronic systemic condition requiring a multidisciplinary and personalized approach.
Improved awareness and earlier diagnosis may ultimately lead to better long-term health outcomes and more effective fertility care for affected women.
References
- Teede HJ, et al. Polyendocrine Metabolic Ovarian Syndrome, the new name for Polycystic Ovary Syndrome: a multistep global consensus process. The Lancet. 2026.
- International Evidence-Based Guideline for the Assessment and Management of Polycystic Ovary Syndrome. 2023.
- Society for Endocrinology. Polyendocrine Metabolic Ovarian Syndrome (PMOS) is the new name for PCOS. 2026.
FAQs
Does the new name change the diagnosis or treatment?
No. The diagnostic criteria and treatment recommendations remain unchanged. The new terminology simply provides a more accurate description of the condition and supports earlier recognition and comprehensive care.
Can Polyendocrine Metabolic Ovarian Syndrome affect fertility?
Yes. PMOS is one of the leading causes of ovulatory infertility. Irregular or absent ovulation may make it more difficult to conceive, although many women achieve pregnancy with appropriate medical management.
Do all women with PMOS have ovarian cysts?
No. Despite the former name, women with PMOS do not have true ovarian cysts. Ultrasound typically shows multiple small follicles that have stopped developing, which can resemble cysts but are not pathological cysts.
Why is insulin resistance important in PMOS?
Insulin resistance plays a central role in PMOS because elevated insulin levels stimulate androgen production, disrupt ovulation and increase the risk of long-term metabolic complications such as type 2 diabetes and cardiovascular disease.
