| "Vrouwen helpen hun ovulatie slimmer bij te houden" | 
Key takeaways
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You do not need cysts on your ovaries to be diagnosed with polyendocrine metabolic ovarian syndrome (PMOS, formerly PCOS).
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What appears on ultrasound is a larger-than-usual number of small immature follicles, not cysts.
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Ovarian appearance is only one of three diagnostic features, and only two of the three are required.
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It is entirely possible to meet the criteria with a completely normal-looking ultrasound.
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Ultrasound is not recommended for diagnosis in adolescents or within eight years of a first period.
No. You do not need ovarian cysts to have PMOS. What shows on an ultrasound is a higher-than-usual number of small immature follicles, not cysts. Ovarian appearance is only one of three diagnostic features and only two are required, so a person with entirely normal-looking ovaries can still meet the criteria.
Do you need cysts on your ovaries to have PMOS?
No. This is one of the most common misunderstandings about the condition, and it was one of the reasons the name was changed.
Cleveland Clinic states directly that you do not need to have cysts on your ovaries to have the condition.1
The diagnostic criteria do not require it, and a substantial number of people are diagnosed with normal-looking ovaries.
If you were told your ultrasound was clear and then received this diagnosis anyway, nothing has gone wrong. If you were told the opposite, that a clear scan ruled it out, that was not correct under current criteria, and it is worth raising with a clinician.
What is actually visible on the ultrasound?
Follicles, not cysts.
Every ovary contains follicles: small fluid-filled sacs, each holding an immature egg. In every cycle a group of them begins to develop, and normally one becomes dominant, matures, and releases its egg. The others break down.2
In PMOS, that selection process is disrupted. More follicles begin developing, but the usual selection of a single dominant one does not happen reliably, so a larger number of small immature follicles remain visible at the same time.2
These are a normal ovarian structure present in higher-than-usual numbers. A cyst is something different — a distinct fluid-filled sac that forms as an abnormality. The follicles seen and counted on ultrasound are small ovarian follicles, not pathological ovarian cysts. They are not pathological cysts and do not require removal simply because they are present.
So why was it called “polycystic”?
Because the name described what the ovaries looked like to early observers, not what was actually there.
The appearance was described long before the underlying hormonal and metabolic mechanisms were understood. On the imaging available at the time, many small follicles read as many small cysts, and the name stuck for decades after the biology had been better characterised.
This was part of the rationale for the 2026 renaming to polyendocrine metabolic ovarian syndrome.3 The new name describes the mechanism — multiple endocrine glands involved, with metabolic features — rather than a visual impression that was never quite accurate and that caused ongoing confusion for patients and clinicians alike.
How is PMOS actually diagnosed?
In adults, diagnosis requires two of three features, after other causes have been excluded:4
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Hyperandrogenism — higher androgen levels, identified clinically or through blood tests
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Ovulatory dysfunction — irregular or absent ovulation
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Polycystic ovarian morphology — the ovarian appearance described above, on ultrasound, or an elevated anti-Müllerian hormone (AMH) level in adults
Two of three. Not all three. This is the part that resolves most of the confusion: someone with hyperandrogenism and irregular cycles meets the criteria with no ultrasound finding at all. The ovarian appearance is one route to one of three boxes, and it is optional.
What actually counts as polycystic ovarian morphology?
For anyone who wants the specifics, the 2023 International Evidence-Based Guideline sets these thresholds for adults:4
| Measure | Threshold |
|---|---|
| Follicle number per ovary (FNPO) | 20 or more in at least one ovary — the preferred marker |
| Ovarian volume | 10 ml or more in at least one ovary |
| Follicle number per cross-section (FNPS) | 10 or more in at least one ovary |
Ovarian volume and cross-section counts are used where older equipment or image quality make an accurate whole-ovary follicle count impractical.4 Where an ultrasound is indicated and acceptable to the person, a transvaginal approach is the most accurate.4
Note what none of these thresholds mention: cysts.
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When is ultrasound not used?
In adolescents, and in anyone within about eight years of their first period.
The guideline is explicit that there are no definitive criteria for defining polycystic ovarian morphology on ultrasound in adolescents, and it is therefore not recommended for diagnosis in that group.4 AMH is not recommended in this group either, because normal developing ovaries in the years after menarche can look very similar.
This is a deliberate protection against overdiagnosis at an age where the picture naturally overlaps with ordinary development. For adolescents, diagnosis rests on the other two features.
What if my ultrasound was normal?
A normal-looking ultrasound does not rule out PMOS, and it does not mean a diagnosis was wrong.
There are a few reasons your scan might look unremarkable:
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You meet the criteria through the other two features and never needed the third.
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Ovarian appearance can change over time, and a single scan is a snapshot.
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Equipment, technique and approach all affect what can be counted.4
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Imaging was not indicated in your situation.
If you have been told a clear scan means you cannot have PMOS, that is worth a second conversation.
Under current criteria, ovarian appearance is neither necessary nor sufficient on its own.
What this means for tracking with Premom
Premom is an ovulation tracking application. It is not intended to diagnose, treat, cure, or prevent any disease, including PMOS. The information provided is for educational purposes and should not replace consultation with a healthcare provider.
Of the three diagnostic features, only one — ovulatory dysfunction — relates to anything a cycle tracking app records, and even then only indirectly. An app records the dates you enter and the test results you log. A clinician assesses whether those patterns meet a clinical definition. Those are different activities, and no app performs the second.
What a record of several months of cycle dates does offer is something specific to bring to an appointment. Cycle history is difficult to reconstruct accurately from memory, and it is one of the things a clinician will ask about.
Track your cycle dates in the Premom app
When to talk to a clinician
The information here is general and is not a basis for self-diagnosis. Speak with a clinician if:
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You were told a clear ultrasound rules out PMOS
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Your cycles are consistently long or vary widely from month to month
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You have symptoms that concern you and have not been assessed
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You have a diagnosis you do not feel was explained properly — that is a reasonable thing to ask someone to revisit
Frequently asked questions
Yes. Ovarian appearance is one of three diagnostic features and only two are required, so someone with hyperandrogenism and irregular cycles meets the criteria with no ultrasound finding at all. A clear scan does not rule the condition out.
The follicles seen and counted on ultrasound are small ovarian follicles, not pathological ovarian cysts. They do not require removal simply because they are present.
They are not something that resolves or is cleared. Ovarian appearance can change over time, and a single scan is a snapshot rather than a permanent picture. What that looks like for you is something to discuss with a clinician.
The count is used as a diagnostic threshold, not a severity scale. The adult threshold is 20 or more follicles in at least one ovary (DOI: 10.1210/clinem/dgad463). Being above it establishes one feature; it does not grade how the condition affects you.
That depends on your situation, and it is a reasonable question to put to your clinician. Where irregular cycles and hyperandrogenism are both present, an ultrasound is not required for diagnosis. Ultrasound is also not recommended within about eight years of a first period.
About PMOS
Polycystic ovary syndrome was renamed polyendocrine metabolic ovarian syndrome (PMOS) by international consensus published in The Lancet on 12 May 2026.3 A three-year transition runs to 2028, and both names remain in clinical use during that period.
The diagnostic criteria did not change with the name. An existing PCOS diagnosis remains valid, and no action is needed because of the rename. Reported prevalence varies with the criteria applied; the 2023 International Evidence-Based Guideline reports 10–13% (DOI: 10.1210/clinem/dgad463).4
References
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Cleveland Clinic. Polyendocrine Metabolic Ovarian Syndrome (PMOS). Cleveland Clinic Health Library. Accessed 15 September 2026.
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Strauss JF III, Barbieri RL, eds. Yen & Jaffe’s Reproductive Endocrinology: Physiology, Pathophysiology, and Clinical Management. 8th ed. Elsevier; 2019. ISBN 978-0-323-47912-7.
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Teede HJ, et al. The Lancet, 12 May 2026. DOI 10.1016/S0140-6736(26)00717-8 · PMID 42119588.
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Teede HJ, et al. Recommendations from the 2023 International Evidence-Based Guideline for the Assessment and Management of Polycystic Ovary Syndrome. J Clin Endocrinol Metab. 2023;108(10):2447–2469. DOI 10.1210/clinem/dgad463 · PMID 37580314. Recommendations 1.1.1, 1.4.1, 1.4.4, 1.4.5, 1.4.6, 1.4.7.
