Rotterdam Criteria: How PCOS Is Actually Defined

What are the Rotterdam criteria?

The Rotterdam criteria are the most widely used way to define PCOS, and they require any two of three findings. According to the 2023 international guideline, the three features are irregular or infrequent ovulation, clinical or biochemical signs of high androgens, and polycystic-appearing ovaries on ultrasound or a high anti-Müllerian hormone level in adults 1Ref 1Teede HJ, Tay CT, Laven J, et al. (International PCOS guideline consortium) (2023).Recommendations From the 2023 International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome.2023 international guideline specifying the Rotterdam two-of-three criteria, allowing anti-Mullerian hormone as an alternative to ultrasound in adults, advising against ultrasound diagnosis within 8 years of menarche, and requiring both irregular cycles and androgen excess in adolescents.. Meeting any two is enough.

That two-of-three structure is deliberate. ACOG notes that no single test diagnoses PCOS; the pattern of features, taken together, does 2Ref 2American College of Obstetricians and Gynecologists (2018).ACOG Practice Bulletin No. 194: Polycystic Ovary Syndrome.ACOG Practice Bulletin confirming no single test diagnoses PCOS and that thyroid disease, hyperprolactinemia, and non-classic congenital adrenal hyperplasia must be excluded first.. Because the criteria were designed to be inclusive, they capture a broad range of presentations rather than one fixed picture.

Why can two women with PCOS look nothing alike?

Two women can both have PCOS yet share none of the same visible symptoms, because they meet different pairs of criteria. One might have irregular cycles plus high androgens with normal-looking ovaries, while another has regular-seeming cycles plus polycystic ovaries and prominent acne 1Ref 1Teede HJ, Tay CT, Laven J, et al. (International PCOS guideline consortium) (2023).Recommendations From the 2023 International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome.2023 international guideline specifying the Rotterdam two-of-three criteria, allowing anti-Mullerian hormone as an alternative to ultrasound in adults, advising against ultrasound diagnosis within 8 years of menarche, and requiring both irregular cycles and androgen excess in adolescents.. Each satisfies the two-of-three rule through a different combination.

This is also why body size, skin, and cycle length vary so much between people with the same label. The PCOS symptom picture reflects that range. According to the Endocrine Society, androgen excess can show up as unwanted hair growth in some women and barely at all in others 3Ref 3Legro RS, et al. (Endocrine Society) (2013).Diagnosis and treatment of polycystic ovary syndrome: an Endocrine Society clinical practice guideline.Endocrine Society guideline describing how androgen excess can present as hirsutism in some women and minimally in others, explaining varied presentations..

What must be ruled out first?

Before the Rotterdam criteria can be applied, a clinician rules out other conditions that copy its features. According to ACOG, thyroid disease, high prolactin, and non-classic congenital adrenal hyperplasia can all cause irregular cycles or excess androgens and must be excluded first 2Ref 2American College of Obstetricians and Gynecologists (2018).ACOG Practice Bulletin No. 194: Polycystic Ovary Syndrome.ACOG Practice Bulletin confirming no single test diagnoses PCOS and that thyroid disease, hyperprolactinemia, and non-classic congenital adrenal hyperplasia must be excluded first.. Simple blood tests, including a thyroid panel, usually cover these.

Other causes of missed periods matter too. Very low energy availability from heavy training or undereating can stop ovulation and mimic PCOS, a pattern called functional hypothalamic amenorrhea rather than PCOS 1Ref 1Teede HJ, Tay CT, Laven J, et al. (International PCOS guideline consortium) (2023).Recommendations From the 2023 International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome.2023 international guideline specifying the Rotterdam two-of-three criteria, allowing anti-Mullerian hormone as an alternative to ultrasound in adults, advising against ultrasound diagnosis within 8 years of menarche, and requiring both irregular cycles and androgen excess in adolescents.. Sorting these out prevents the wrong label, which is why irregular periods have many causes worth checking with tests.

How do the criteria change for adolescents?

The criteria are applied more cautiously in teenagers, because normal puberty overlaps with PCOS features. In the first years after a first period, cycles are often irregular and acne is common, so ACOG frames the menstrual cycle as a vital sign to track rather than an instant diagnosis 4Ref 4American College of Obstetricians and Gynecologists (2015).ACOG Committee Opinion No. 651: Menstruation in Girls and Adolescents: Using the Menstrual Cycle as a Vital Sign.ACOG committee opinion framing the menstrual cycle as a vital sign and noting normal cycle variability in the years after menarche.. Ovulatory cycles typically settle into a range of about 21 to 35 days over time.

For this reason, the 2023 guideline advises against using ultrasound to diagnose PCOS within 8 years of the first period and requires both irregular cycles and clear androgen excess in adolescents 1Ref 1Teede HJ, Tay CT, Laven J, et al. (International PCOS guideline consortium) (2023).Recommendations From the 2023 International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome.2023 international guideline specifying the Rotterdam two-of-three criteria, allowing anti-Mullerian hormone as an alternative to ultrasound in adults, advising against ultrasound diagnosis within 8 years of menarche, and requiring both irregular cycles and androgen excess in adolescents.. As women later reach the perimenopausal transition, cycle patterns shift again, so the criteria are read in the context of life stage.

When applying the Rotterdam criteria needs a clinician

A clinician applies the Rotterdam criteria to your specific findings and confirms that mimics have been excluded. When your cycles are irregular or androgen symptoms appear, a primary-care clinician or gynecologist can decide which two of the three features you meet and whether ultrasound or blood tests add anything. According to major guidelines, the criteria are a starting framework, not a verdict, and they always sit alongside your history 1Ref 1Teede HJ, Tay CT, Laven J, et al. (International PCOS guideline consortium) (2023).Recommendations From the 2023 International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome.2023 international guideline specifying the Rotterdam two-of-three criteria, allowing anti-Mullerian hormone as an alternative to ultrasound in adults, advising against ultrasound diagnosis within 8 years of menarche, and requiring both irregular cycles and androgen excess in adolescents.. Gale can help you prepare for that conversation.