Endocrinology · Reproductive Endocrinology
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In adults, diagnosis requires at least two of the three Rotterdam criteria: oligo- or anovulation, clinical or biochemical hyperandrogenism, and polycystic ovaries on ultrasound (or an elevated anti-Müllerian hormone as an alternative to ultrasound); in adolescents, both hyperandrogenism and ovulatory dysfunction are required and ultrasound/AMH are not used.
The classic hormonal profile may reveal an elevated LH:FSH ratio (often >2:1), though this is a supportive finding and NOT a Rotterdam diagnostic criterion; elevated free testosterone is typical.
Patients frequently present with hirsutism, acne, and androgenic alopecia due to androgen excess, amplified by local conversion of testosterone to dihydrotestosterone (DHT) in the pilosebaceous unit.
Combined oral contraceptive pills (COCPs) are the first-line therapy for menstrual regulation and protection against endometrial hyperplasia caused by unopposed estrogen.
Metformin is the preferred second-line agent for patients with insulin resistance or those who fail to respond to lifestyle modifications.
Letrozole is the first-line pharmacological treatment for ovulation induction in patients desiring pregnancy, superior to clomiphene citrate.
Long-term management should include screening for metabolic syndrome, type 2 diabetes mellitus, and, when suggestive symptoms are present, obstructive sleep apnea (2023 International PCOS Guideline).
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A 22-year-old female presents to the clinic complaining of irregular menses and unwanted facial hair growth. She reports having only 4-5 periods per year since menarche. Physical examination reveals acanthosis nigricans in the axilla and hirsutism on the chin and upper lip. Laboratory evaluation shows an elevated free testosterone level and a normal 17-hydroxyprogesterone. Pelvic ultrasound demonstrates multiple peripheral follicles in both ovaries.
What is the most appropriate first-line pharmacotherapy for this patient's menstrual irregularities?
Combined oral contraceptive pills
The patient meets all three Rotterdam criteria for PCOS; COCPs are the first-line treatment to regulate cycles and prevent endometrial hyperplasia by providing progestin-mediated shedding.
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Etiology / Epidemiology
Common endocrine disorder characterized by insulin resistance and hyperandrogenism in reproductive-age women.
Clinical Manifestations
Presents with oligomenorrhea, hirsutism, and acanthosis nigricans due to metabolic dysfunction.
Diagnosis
Requires 2 of 3 Rotterdam Criteria: oligo/anovulation, hyperandrogenism, or polycystic ovaries on transvaginal ultrasound (or elevated AMH as an alternative in adults); in adolescents, both hyperandrogenism and ovulatory dysfunction are required and imaging/AMH are not used.
Treatment
Combined oral contraceptives are first-line; do not use if history of VTE.
Prognosis
High risk for endometrial hyperplasia and type 2 diabetes mellitus.
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Epidemiology & Etiology
PCOS is the most common cause of anovulatory infertility. It is strongly associated with obesity and metabolic syndrome, affecting 10-13% of reproductive-age women.
Pertinent Anatomy
The ovaries exhibit a string of pearls appearance on imaging, representing multiple peripheral follicles. Chronic anovulation prevents the formation of a dominant follicle and subsequent corpus luteum.
Pathophysiology
Increased LH:FSH ratio stimulates ovarian theca cells to produce excess androgens. Peripheral conversion of androgens to estrogens, combined with low FSH, prevents follicular maturation. Hyperinsulinemia directly augments theca-cell androgen production and, separately, suppresses hepatic sex hormone-binding globulin (SHBG) synthesis, which raises free testosterone.
Clinical Manifestations
Patients present with oligomenorrhea or amenorrhea. Physical exam reveals hirsutism (Ferriman-Gallwey score), acanthosis nigricans, and acne. Red flags include rapid onset of virilization, which necessitates ruling out androgen-secreting tumors.
Diagnosis
Diagnosis is clinical using the Rotterdam Criteria. Transvaginal ultrasound confirms polycystic morphology (≥20 follicles per ovary or ovarian volume ≥10 mL); per the 2023 International Evidence-Based Guideline, serum anti-Müllerian hormone (AMH) may be used as an alternative to ultrasound in adults. In adolescents (within 8 years of menarche), both hyperandrogenism and ovulatory dysfunction are required, and ultrasound and AMH should not be used because of poor specificity. Exclude other causes like congenital adrenal hyperplasia (17-OH progesterone) and Cushing syndrome.
Treatment
Combined oral contraceptives (COCs) regulate menses and suppress ovarian androgen production. Spironolactone is the preferred anti-androgen for hirsutism; teratogenic (effective contraception is recommended). Metformin is used for insulin resistance, while letrozole is the first-line agent for ovulation induction.
Prognosis
Long-term risks include endometrial cancer due to unopposed estrogen and metabolic syndrome. Glycemic screening with a 2-hour 75g oral glucose tolerance test (preferred; alternatively fasting glucose or HbA1c) is recommended at diagnosis and repeated every 1-3 years based on risk.
Differential Diagnosis
Congenital Adrenal Hyperplasia: elevated 17-hydroxyprogesterone
Cushing Syndrome: elevated 24-hour urinary free cortisol
Androgen-secreting tumor: rapid virilization and very high testosterone
Hyperprolactinemia: elevated serum prolactin levels
Hypothyroidism: elevated TSH levels