Key Points
- Confirm diagnosis using Rotterdam criteria after excluding mimics.
- Screen for metabolic comorbidities at diagnosis and periodically.
- Cycle regulation: combined OCPs or cyclic progestin.
- Metformin for metabolic indications or selected menstrual dysfunction.
- Letrozole is first-line for ovulation induction in infertility.
Algorithm
- History, exam, and pregnancy test.
- Screen for mimics: TSH, prolactin, 17-hydroxyprogesterone, androgen levels as indicated.
- Assess metabolic health: BMI, blood pressure, lipid panel, glucose or A1c.
- Apply Rotterdam criteria.
- Initiate goal-driven management: cycle control, androgen reduction, metabolic therapy, fertility support.
- Arrange follow-up for metabolic risk and therapy response.
Clinical Synopsis & Reasoning
PCOS is a heterogeneous endocrine–metabolic disorder characterized by ovarian dysfunction and androgen excess. Apply the modified Rotterdam criteria (≥2 of: oligo/anovulation, clinical or biochemical hyperandrogenism, polycystic ovarian morphology on ultrasound). Exclude mimics including thyroid disease, hyperprolactinemia, non-classic congenital adrenal hyperplasia, Cushing syndrome, pregnancy, and androgen-secreting tumors. Evaluate metabolic comorbidities early (obesity, insulin resistance, dyslipidemia, prediabetes/diabetes, fatty liver) to guide counseling and long-term risk reduction.
Treatment Strategy & Disposition
Treatment aligns with patient goals: (1) regulate bleeding, (2) reduce androgenic symptoms, (3) address metabolic risk, and/or (4) support fertility. First-line therapy for irregular menses includes combined hormonal contraceptives; cyclic progestin is an alternative when estrogen is contraindicated. Add metformin for metabolic indications or when menstrual irregularities persist despite lifestyle interventions. For hirsutism/acne, combined OCPs are first line; add spironolactone as needed after 6 months if contraception is reliable. For fertility, prioritize lifestyle optimization, then initiate ovulation induction—letrozole preferred over clomiphene. Refer to reproductive endocrinology for resistant cases or complex infertility.
Epidemiology / Risk Factors
- Affects up to ~10% of reproductive-aged women depending on criteria.
- Strong association with obesity, insulin resistance, and family history of type 2 diabetes.
- Higher prevalence of metabolic syndrome and gestational diabetes.
Investigations
| Test | Role / Rationale | Typical Findings | Notes |
|---|---|---|---|
| Pregnancy test (hCG) | Exclude pregnancy in amenorrhea | Negative | Always first step in reproductive-age patients |
| TSH | Rule out thyroid dysfunction | Normal | Hypo- or hyperthyroidism may mimic PCOS |
| Prolactin | Exclude hyperprolactinemia | Normal | Marked elevation prompts pituitary workup |
| 17-hydroxyprogesterone (AM) | Screen for non-classic CAH | Normal | Elevated suggests 21-hydroxylase deficiency |
| Total/free testosterone ± DHEAS | Assess hyperandrogenism | Mild elevation | Very high levels suggest androgen-secreting tumor |
| Fasting glucose or 2-h OGTT ± HbA1c | Screen for insulin resistance and diabetes | Prediabetes/diabetes in subset | Repeat periodically |
| Lipid panel | Assess cardiovascular/metabolic risk | Dyslipidemia common | |
| Transvaginal pelvic ultrasound (if needed) | Assess for polycystic ovarian morphology and endometrial thickness | Increased follicle count or ovarian volume | Not required if other criteria already met |
Diagnostic Criteria (Modified Rotterdam)
| Criterion | Details |
|---|---|
| Oligo- or anovulation | Cycle length >35 days, <8 cycles/year, or chronic anovulation |
| Hyperandrogenism | Clinical (hirsutism, acne, androgenic alopecia) and/or biochemical (elevated androgens) |
| Polycystic ovarian morphology (optional) | ≥20 follicles per ovary and/or ovarian volume ≥10 mL on transvaginal ultrasound (machine-dependent) |
Pharmacology
| Medication | Mechanism | Onset | Role in Therapy | Limitations |
|---|---|---|---|---|
| Combined oral contraceptives | Suppress LH/FSH and ovarian androgen production; increase SHBG | Weeks | First-line for cycle regulation, acne, and hirsutism | Estrogen contraindications; VTE risk in susceptible patients |
| Metformin | Improves hepatic and peripheral insulin sensitivity | Weeks | Metabolic indications (prediabetes/diabetes, insulin resistance); may improve ovulation | GI upset, B12 deficiency; not primary cosmetic therapy |
| Spironolactone | Androgen receptor blocker and 5α-reductase inhibition | Months | Adjunct for hirsutism/acne after 6 months of OCPs | Teratogenic; must use reliable contraception; hyperkalemia risk |
| Letrozole | Aromatase inhibitor increasing FSH and follicular recruitment | Per cycle | First-line ovulation induction in anovulatory infertility | Ovulation monitoring needed; multiple gestation risk |
| Clomiphene citrate | Selective estrogen receptor modulator that increases gonadotropin release | Per cycle | Second-line ovulation induction when letrozole unavailable or ineffective | Anti-estrogenic endometrial effects; visual side effects (rare) |
| Topical treatments (e.g., eflornithine, acne therapies) | Local anti-androgen or comedolytic effects | Weeks | Adjunct for hirsutism and acne | Cosmetic only; do not treat systemic features |
Prognosis / Complications
- Chronic but manageable condition with targeted lifestyle and medical therapy.
- Improved outcomes with early identification of metabolic disease and regular follow-up.
- Long-term risks include type 2 diabetes, dyslipidemia, endometrial hyperplasia/cancer, and psychosocial burden.
Patient Education / Counseling
- Explain the diagnosis, that PCOS is common, and that symptoms are treatable.
- Discuss weight, nutrition, and activity as disease-modifying tools rather than appearance-focused goals.
- Review fertility expectations: many patients conceive with lifestyle optimization and ovulation induction.
- Address mental health, body image, and screening for anxiety/depression.
Notes
PCOS is a diagnosis of exclusion that requires a systematic workup for endocrine mimics and metabolic disease. Ultrasound criteria are evolving and depend on machine resolution; morphology alone without hyperandrogenism or ovulatory dysfunction does not define PCOS. Lifestyle interventions (nutrition, physical activity, sleep, and smoking cessation) are foundational for all phenotypes. Coordinate care with primary care, endocrinology, reproductive medicine, dermatology, and mental health as patient needs evolve.
References
- Endocrine Society PCOS Guideline — Link
- ACOG Practice Bulletin — PCOS — Link
- International Evidence-Based Guideline for PCOS — Link
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