Evaluation of primary amenorrhea
Primary amenorrhea is the absence of menses by age 15 years with normal growth and secondary sexual development, or by age 13 years without it, and is worked up by a fixed algorithm that branches on secondary sexual characteristics, uterine presence, and gonadotropin level, then treated by cause with titrated estrogen replacement, surgery, or dilators. Genetic and anatomic causes account for the great majority of cases, led by gonadal dysgenesis (Turner syndrome) and mullerian agenesis.
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What this article covers
- Overview
A branch-point algorithm, not a single disease: a fixed sequence of history, exam, and labs localizes the defect to the hypothalamic-pituitary axis, the ovary, the uterus, or the outflow tract.
- Epidemiology
Genetic causes account for about 50% of cases and anatomic causes for about 15%: gonadal dysgenesis, chiefly Turner syndrome, is the leading etiology, followed by mullerian agenesis.
- Risk factors
Family history of delayed puberty or infertility: a first-degree relative with primary ovarian insufficiency, Turner features, or mullerian anomalies raises pretest suspicion.
- Pathophysiology
Normal menstruation requires an intact hypothalamic-pituitary-ovarian axis plus a patent outflow tract: pulsatile GnRH drives pituitary follicle-stimulating hormone (FSH) and luteinizing hormone…
- Clinical features
Absence of menses, sorted first by two exam findings: whether secondary sexual characteristics (breast development) are present, and, if so, whether a uterus is present on exam or ultrasound; this…
- Differential diagnosis
Turner syndrome (gonadal dysgenesis): short stature, absent secondary sexual characteristics, elevated FSH/LH, 45,X karyotype confirms it; the single most common cause.
- Diagnosis
Established by working through a fixed branch-point algorithm, not a single test: first localize by secondary sexual characteristics present or absent, then uterus present or absent, then FSH/LH…
- Management
First, treat the specific cause identified by the algorithm; management branches immediately once the diagnosis is made.
- Complications
Osteoporosis and fracture risk from prolonged hypoestrogenism: untreated Turner syndrome, primary ovarian insufficiency, or functional hypothalamic amenorrhea cause bone loss if hormone therapy is delayed.
- Prognosis
Outcome is dictated by the underlying cause: constitutional growth delay resolves spontaneously; anatomic causes are corrected surgically or with dilators; hormonal causes require lifelong replacement.
- Prevention
There is no primary prevention for congenital causes (Turner syndrome, mullerian agenesis, androgen insensitivity); prevention here means timely detection.
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Related articles
- Turner syndrome
Turner syndrome is a 45,X (or mosaic-variant) chromosomal disorder causing gonadal dysgenesis, short stature, and a characteristic phenotype including webbed neck, coarctation of the aorta, and horseshoe kidney. Karyotype confirms the diagnosis, and management centers on growth hormone in childhood and estrogen-based pubertal induction with lifelong cardiovascular and metabolic surveillance.
- Mullerian agenesis
Mullerian agenesis (Mayer-Rokitansky-Kuster-Hauser syndrome) is congenital failure of paramesonephric duct development in a 46,XX individual, producing primary amenorrhea with absent uterus and cervix, a short or absent vagina, and normal ovarian function, managed with vaginal dilator therapy and psychosocial support.
- Hypothalamic amenorrhea
Functional hypothalamic amenorrhea is a diagnosis of exclusion caused by stress, weight loss, or excessive exercise disrupting pulsatile GnRH secretion, producing hypogonadotropic hypogonadism with low LH, FSH, and estradiol; first-line treatment is increasing caloric intake and reducing exercise, with transdermal estrogen-progestin replacement added if menses do not return after 6 to 12 months.
- Primary ovarian insufficiency
Primary ovarian insufficiency is loss of ovarian follicular function before age 40, defined by amenorrhea with a low estradiol and an elevated FSH on two occasions a month apart. It carries fertility, bone, and cardiovascular consequences that estrogen replacement, continued until the normal age of menopause, is meant to prevent.
- Congenital adrenal hyperplasia
Congenital adrenal hyperplasia is a family of autosomal recessive enzyme defects in adrenal steroidogenesis that impair cortisol synthesis, drive ACTH-mediated adrenal hyperplasia, and shunt steroid precursors toward androgen or mineralocorticoid excess depending on which enzyme is deficient. First-line treatment is lifelong glucocorticoid replacement, with mineralocorticoid replacement added when salt wasting is present.
- 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.
- Hyperprolactinemia
Hyperprolactinemia is an elevated serum prolactin level with causes ranging from physiologic states and medications to hypothyroidism, renal failure, and a prolactin-secreting pituitary tumor. Diagnosis requires a confirmed elevated prolactin with exclusion of pregnancy, medication effect, and hypothyroidism before attributing the finding to a pituitary adenoma, and first-line treatment for a symptomatic pituitary cause is a dopamine agonist such as cabergoline.
- Evaluation of secondary amenorrhea
Secondary amenorrhea is absence of menses for 3 months in a woman with prior regular cycles or 6 months with prior irregular cycles, worked up stepwise with beta-hCG, TSH, prolactin, and a progesterone challenge test, then treated with the cause-specific therapy (cyclic progestin, dopamine agonist, thyroid replacement, or estrogen replacement).