Polycystic ovary syndrome
Polycystic ovary syndrome (PCOS) is a hyperandrogenic disorder of chronic anovulation and is the most common cause of hirsutism and anovulatory infertility in women. First-line treatment is weight loss for patients with an elevated BMI, combined oral contraceptives for menstrual dysfunction and hirsutism when fertility is not desired, and clomiphene citrate or letrozole for ovulation induction when fertility is desired.
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What this article covers
- Overview
Definition: polycystic ovary syndrome (PCOS) is a hyperandrogenic disorder characterized by chronic oligo-ovulation or anovulation, clinical or biochemical signs of androgen excess, and, in some…
- Epidemiology
Prevalence: PCOS affects approximately 6% to 10% of women of reproductive age, making it the most common endocrine disorder in this population.
- Risk factors
Obesity: a high BMI, particularly above 30, is frequently seen in women with PCOS and amplifies the hyperandrogenism and insulin resistance that drive the syndrome.
- Pathophysiology
Gonadotropin dysregulation: rapid hypothalamic GnRH pulsatility favors pituitary luteinizing hormone (LH) secretion over follicle-stimulating hormone (FSH), and the resulting excess LH stimulates…
- Clinical features
Diagnostic core feature: the defining clinical pattern is menstrual irregularity from oligo-ovulation or anovulation combined with clinical or biochemical signs of hyperandrogenism, most often…
- Differential diagnosis
Nonclassical congenital adrenal hyperplasia: hyperandrogenism and irregular cycles overlap with PCOS, but an elevated morning 17-hydroxyprogesterone level, rather than a normal one, identifies 21-hydroxylase deficiency as the cause.
- Diagnosis
Diagnostic criteria: PCOS is diagnosed using the Rotterdam criteria (2 of 3: oligo-/anovulation, clinical or biochemical hyperandrogenism, or a polycystic ovarian morphology finding) or the more…
- Management
First, recommend weight loss for patients with a BMI of 25 or greater: sustained weight loss of 5% to 10% improves androgen levels, menstrual function, and possibly fertility, and is first-line…
- Complications
Infertility: chronic anovulation is a leading cause of difficulty conceiving and may require assisted reproductive techniques if ovulation induction with clomiphene or letrozole fails.
- Prognosis
Chronic but manageable: PCOS is a lifelong condition, but menstrual regularity, hirsutism, and metabolic risk can be substantially improved with weight management and appropriate pharmacotherapy.
- Prevention
Routine metabolic screening at diagnosis and periodically thereafter: screen every patient with PCOS for prediabetes or diabetes, hypercholesterolemia, obesity, hypertension, and obstructive sleep…
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