ObGyn Intelligence — Women's Health

PCOS Screener

Rotterdam criteria-based assessment for polycystic ovary syndrome. Covers all four diagnostic phenotypes with exclusion of mimicking conditions.

Evidence Base

Rotterdam ESHRE/ASRM-Sponsored PCOS Consensus Workshop Group. Revised 2003 consensus on diagnostic criteria and long-term health risks related to polycystic ovary syndrome (PCOS). Hum Reprod. 2004;19(1):41–47. — Defines the Rotterdam diagnostic criteria used in this tool.
Teede HJ, Misso ML, Costello MF, et al. Recommendations from the international evidence-based guideline for the assessment and management of polycystic ovary syndrome. Hum Reprod. 2018;33(9):1602–1618. — International guideline for PCOS diagnosis and management.
American College of Obstetricians and Gynecologists. Polycystic Ovary Syndrome. ACOG Practice Bulletin No. 194. Obstet Gynecol. 2018;131(6):e157–e171. — ACOG recommendations for clinical assessment and exclusion of mimicking conditions.
Azziz R, Carmina E, Dewailly D, et al. The Androgen Excess and PCOS Society criteria for the polycystic ovary syndrome: the complete task force report. Fertil Steril. 2009;91(2):456–488. — AES criteria requiring hyperandrogenism as a mandatory feature.

How This Tool Works

PCOS is diagnosed using the Rotterdam criteria (2004): at least 2 of the following 3 features must be present, after excluding other causes.

Criterion	What It Means
1. Oligo/Anovulation	Irregular or absent periods — cycles >35 days or fewer than 8 cycles per year
2. Hyperandrogenism	Clinical (hirsutism, acne, alopecia) or biochemical (elevated testosterone or DHEAS)
3. Polycystic ovarian morphology	≥20 follicles in either ovary on ultrasound, or ovarian volume >10 mL (updated 2018 threshold)

Note: This tool screens for PCOS based on reported symptoms and available test results. A formal diagnosis requires clinical evaluation, examination, and laboratory testing by a qualified clinician.

Criterion 1 of 3

Menstrual Cycle Pattern

Select the description that best fits the typical cycle pattern over the past 12 months.

Regular cycles — every 24 to 35 days

Irregular cycles — varies by more than 7–9 days cycle to cycle

Infrequent cycles — more than 35 days apart, or fewer than 8 cycles per year

Absent cycles — no period for 3 or more months (not pregnant, not menopausal)

Criterion 2 of 3

Signs of Excess Androgens

Check all that apply. Either clinical signs or lab findings count toward this criterion.

Clinical Signs

Hirsutism — unwanted hair growth on face, chest, abdomen, or back (modified Ferriman-Gallwey score ≥4–6)

Most specific clinical sign of androgen excess

Persistent acne — not responding to standard treatment, especially jawline or cystic

Female-pattern hair thinning — crown or top of scalp (androgenic alopecia)

Lab Findings (if available)

Elevated total or free testosterone — above lab reference range for women

Morning fasting sample preferred; free testosterone more sensitive

Elevated DHEAS — above lab reference range

Adrenal androgen; elevation may suggest adrenal source

None of the above — no clinical or biochemical evidence of hyperandrogenism

Criterion 3 of 3

Ovarian Ultrasound

If a pelvic ultrasound has been done, what did it show? Skip if no ultrasound is available.

Polycystic ovarian morphology — ≥20 follicles (2–9 mm) in either ovary, or ovarian volume >10 mL

Updated threshold per 2018 international guideline (Teede et al.); older studies used ≥12 follicles

Normal-appearing ovaries — follicle count and volume within normal limits

No ultrasound done, or result not available

Important: Ultrasound is not required for PCOS diagnosis if the other two Rotterdam criteria are clearly met. Transvaginal ultrasound is preferred for follicle counting. Transabdominal ultrasound may undercount follicles in women with a higher BMI.

Exclusion of Other Diagnoses

Conditions That Can Mimic PCOS

PCOS is a diagnosis of exclusion. Check any known diagnoses that apply — these must be ruled out before PCOS can be confirmed.

Thyroid disease — hypothyroidism or hyperthyroidism (affects cycle regularity)

Hyperprolactinemia — elevated prolactin (causes oligomenorrhea/amenorrhea)

Non-classic congenital adrenal hyperplasia (NCCAH) — 17-hydroxyprogesterone elevation

Cushing syndrome — cortisol excess causing irregular cycles and androgens

Androgen-secreting tumor — suspected based on rapidly progressive virilization

None of the above — no known mimicking conditions