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Polycystic Ovarian Syndrome (PCOS)

BASICS

  • Definition: Common, heterogeneous endocrine disorder (6–10% prevalence). Characterized by:
  • Hyperandrogenism
  • Insulin resistance
  • Anovulation (amenorrhea/oligomenorrhea)
  • Clinical features: Menstrual dysfunction, infertility, hirsutism, acne, obesity, metabolic syndrome. Polycystic ovaries may be seen on imaging but are NOT required for diagnosis.
  • Systems affected: Reproductive, endocrine/metabolic, skin/exocrine.
  • Synonyms: Stein-Leventhal syndrome, polycystic ovary disease.
  • Key point: Obesity may amplify PCOS but is not required; 20% of PCOS women are not obese.
  • Risks: Obesity, hypertension, diabetes, metabolic syndrome, hyperlipidemia, infertility, endometrial hyperplasia, uterine cancer.

EPIDEMIOLOGY

  • Prevalence: 7% of reproductive-age women (NIH criteria)
  • Incidence: Highly variable due to differing diagnostic features
  • Diagnosis: NIH criteria require chronic anovulation & hyperandrogenism

ETIOLOGY & PATHOPHYSIOLOGY

  • Insulin resistance → hyperinsulinemia → decreased SHBG, increased free testosterone
  • Neuroendocrine: Increased GnRH pulsatility → ↑ LH, relative ↓ FSH → ovarian theca cells produce excess androgens
  • Ovarian: Abnormal folliculogenesis due to androgen signaling → polycystic ovaries
  • Obesity: Worsens insulin resistance and hyperandrogenism but is not always present
  • Genetics: Polygenic + environmental; genes: DENND1A, THADA

RISK FACTORS

  • Family history of diabetes, premature CV disease
  • Obesity, metabolic syndrome, insulin resistance

GENERAL PREVENTION

  • No known prevention; early diagnosis and treatment prevent long-term complications

ASSOCIATED CONDITIONS

  • Infertility, obesity, obstructive sleep apnea
  • Hypertension, diabetes mellitus, endometrial hyperplasia/carcinoma, fatty liver disease
  • Mood disturbances, depression, hirsutism

DIAGNOSIS

History

  • Family history (diabetes, early CV disease)
  • Onset/duration of androgen excess, menstrual history, medications
  • Symptoms: Menstrual irregularity, heavy/absent menses, infertility, hirsutism, acne, weight gain

Physical Exam

  • Elevated BMI, hypertension, central obesity
  • Hirsutism (male hair pattern), acne, acanthosis nigricans
  • Ovarian enlargement, clitoromegaly (sign of severe hyperandrogenism)

Differential Diagnosis

  • Cushing syndrome, androgen-secreting tumor
  • HAIR-AN syndrome, thyroid disease, acromegaly, prolactinoma
  • Adrenal hyperplasia, drug-induced hirsutism, idiopathic hirsutism

Diagnostic Criteria

  • Rotterdam Criteria (need 2 of 3):
  • Oligo/amenorrhea
  • Clinical/biochemical hyperandrogenism

  • Polycystic ovaries on ultrasound

  • Exclude other causes (e.g., Cushing, adrenal hyperplasia, androgen-secreting tumor)

Initial Tests

  • Rule out: pregnancy, thyroid disease, hyperprolactinemia, congenital adrenal hyperplasia, premature ovarian failure
  • Labs: hCG, TSH, prolactin, 17-OH progesterone, FSH, free testosterone, DHEA-S
  • Androgen excess: ↑ testosterone (<200 ng/dL), mild ↑ DHEA-S (<800 µg/dL), ↑ estrogen, ↓ SHBG
  • Midluteal progesterone (>3 ng/mL = ovulation)
  • Ultrasound: ≥12 follicles (2–9 mm), or ovarian volume >10 cm³

Other/Follow-Up Tests

  • Fasting glucose, insulin, lipid profile, oral glucose tolerance test
  • Endometrial biopsy if prolonged/heavy bleeding
  • Consider endometrial assessment for risk of hyperplasia/cancer

TREATMENT

General Measures

  • Lifestyle: Nutrition and exercise; weight loss ≥5% can restore ovulation and improve insulin sensitivity

Medication

Restore menses (if pregnancy not desired):

  • Combined OCPs (low-androgenicity progestins preferred)
  • Levonorgestrel IUD (for endometrial protection only)
  • Intermittent progestin (e.g., medroxyprogesterone, micronized progesterone, every 1–3 months)

Decrease insulin resistance:

  • Metformin: Start 500 mg/day, increase to 1,500–2,000 mg/day BID with food
  • Thiazolidinediones: May increase ovulation (not 1st line)

Fertility/ovulation induction (if pregnancy desired):

  • Letrozole (aromatase inhibitor): Preferred, 2.5 mg/day x 5 days, can increase up to 7.5 mg/day x 5 days
  • Clomiphene: Alternative to letrozole
  • Metformin: May continue if history of abortion/glucose intolerance, helps ovulation/insulin resistance

Hirsutism/acne:

  • OCPs with low-androgenicity progestins
  • Spironolactone: 50–200 mg daily (monitor K+, contraindicated in pregnancy)
  • Eflornithine cream, finasteride (with reliable contraception)

Second Line/Other

  • Hair removal: Laser, electrolysis, waxing, depilatory creams
  • Surgical: Rare; ovarian wedge resection, laparoscopic drilling (controversial)

ONGOING CARE

  • Follow-up: Every 6 months to monitor therapy, weight, metabolic risk, and medication side effects
  • Monitor: Risk of endometrial/breast carcinoma, diabetes, obesity, infertility
  • Endometrial biopsy for women with 1 year of amenorrhea without endometrial protection
  • Lifestyle: Encourage weight loss, healthy diet, exercise (no specific diet proven superior)

PROGNOSIS

  • Fertility: Good, but some need ART
  • Complications: Preventable with screening and treatment (endometrial cancer, diabetes, CV risk)
  • Pregnancy: Higher risk for gestational diabetes, hypertensive disorders

ICD-10

  • E28.2 Polycystic ovarian syndrome
  • L68.0 Hirsutism

CLINICAL PEARLS

  • Diagnosis: 2 of 3 — oligo-ovulation, hyperandrogenism, polycystic ovaries; imaging not required
  • Treat anovulation to reduce risk of endometrial hyperplasia/cancer
  • Lifestyle change is first-line therapy for most features