MD Notes

creation date: 2026-01-08 23:11
tags: Pathologies

Polycystic Ovary Syndrome

Background

Definitions

Polycystic ovary syndrome (PCOS) is the most common endocrine condition in females of reproductive age, affecting up to 6-10% of women.

Etiology and Pathogenesis

PCOS is a multigenic disorder with strong epigenetics associated.

Pathogenesis involves aberrancies in ovarian steroidogenesis, insulin resistance, antimullerian hormone, and LH excess from HPO dysfunction. This can summarily be thought of in terms of the bidirectional relation between hyperinsulinemia and androgen excess.

Insulin sensitizes ovary to LH which interferes with normal ovulation cycle resulting in dysregulation of androgen synthesis and the normal feedback cycles. Ovarian hyperandrogenism and hyperandrogenemia causes the many manifestations.

Clinical Presentation

Signs & Symptoms

Reproductive manifestations

  • Menstrual dysfunction (oligo- or amenorrhea due to absent ovulation)
  • Ovarian abnormalities (increased volume of stroma and muliple, small follicles in periphery)
  • Elevated anti-mullerian hormone (AMH) - secreted by follicles
  • Anovulatory infertility
  • Pregnancy complications (higher rates of spontaneous abortion, GDM, hypertensive disorders)

Hyperandrogenism

  • Hirsutism (excess terminal body hair in male distribution)
  • Acne
  • Female pattern hair loss

Metabolic issues

Other manifestations

  • Cardiovascular risk
  • Venous thromboembolism (associated with treatment)
  • Mood disorders

History & Physical Exam

Suspicion of PCOS should occur in any women of reproductive age who:

  • Presents with irregular menses and symptoms of hyperandrogenism
  • Presence of overweight or obesity should raise suspicion further

History should include:

  • Menstrual history
  • Fertility history if applicable

General assessment via physical exam should be made for features of hyperandrogenism and obesity.

The Ferriman-Gallwey score can be used to assess the degree of hirsutism but its use is limited due to variability between individuals and ethnic groups.

Risk factors

  • Family history of PCOS
  • Fetal androgen exposure
  • Family history of metabolic syndrome
  • Obesity or overweight

Diagnosis

Criteria

PCOS is a diagnosis of exclusion with use of clinical criteria. In the absence of an alternative diagnosis, PCOS may be diagnosed if 2 out of the following 3 criteria are present (Rotterdam criteria):

  • Chronic oligo-anovulation
  • Clinical or biological hyperandrogenism
  • Polycystic ovarian morphology (PCOM)

Work-up

As PCOS is a diagnosis of exclusion, the work-up primarily involves ruling out more serious causes of manifestations.

Patients with hyperandrogenism
For patients with normal menstrual cycles:

  • Serum androgen
  • Serum total testosterone
    For patients with oligomenorrhea, further workup is needed to androgen-secreting tumours:
  • Serum androgen
  • Serum total testosterone
  • Early morning 17-hydroxyprogesterone
  • TSH, FSH, hCG, prolactin

Note that androgen measurements are not useful if patients are taking OCPs for treatment of hirsutism. In such case, discontinue medication for 4-6 weeks before measurement.

Patients with symptoms of cortisol excess
Consider other endocrine disorders such as Cushing syndrome.

Transvaginal ultrasound
For patients who do not meet criteria without evidence of polycystic ovarian morphology, ultrasound is used to confirm.

It should be noted that cysts found incidentally without meeting other criteria does not necessitate further workup.

Differential

Diagnoses to rule out include:

  • Use of androgenic steroids
  • Hypothyroidism
  • Nonclassic congenital adrenal hyperplasia (eval: elevated 17-hydroxyprogresterone)
  • Idiopathic/familial hirsutism
  • Androgen secreting tumours (ovarian or adrenal)

Red Flags / Complications

Quality of life is improves with earlier detection and treatment. Generally, PCOS symptoms and manifestations improve with age. However, complications include:

Management

Post-Diagnosis Assessments

Following the diagnosis, evaluation of comorbidities should be performed. This includes:

  • Cardiometabolic risk assessment (blood pressure and BMI, fasting lipid profile, 2h OGTT)
  • Screening for mood disorders
  • Screening for steatotic liver
  • Screening for obstructive sleep apnea

For women who are pursuing fertility, assessment of ovulatory status may be indicated.

General Treatment

Endometrial protection against endometrial hyperplasia and endometrial cancer. Options include:

  • Combined estrogen-progestin oral contraceptive (first-line)
  • Medroxyprogesterone acetate
  • Metformin

Hirsutism

  • Combined oral contraceptive
  • Antiandrogen after 6 months if COC monotherapy inadequate

Metabolic abnormalities
Treatment of obesity, insulin resistance/diabetes, dyslipidemia, MASLD, and obstructive sleep apnea may restore ovulatory cycles and improve metabolic risk.

The management is similar to patients without PCOS.

Pursuing Pregnancy

For anovulatory women with PCOS who are overweight or obese, weight loss is recommended prior to ovulation induction therapy.

Ovulation induction

  • Letrozole (off-label)
  • Clomiphene citrate
  • Metformin
  • Gonadotropin therapy

References

Tools / Guidelines

Additional Reading

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