Amenorrhea: Primary

Introduction

• Description: Primary amenorrhea is the absence of normal menstruation in a patient without previously established cycles.

• Prevalence: Uncommon.

• Predominant Age: Mid to late teens.

• Genetics: One-third caused by chromosomal abnormalities such as 45,XO, 46,XY gonadal dysgenesis, or 46,XX q5 X long-arm deletion.

Etiology and Pathogenesis

• Causes: Gonadal abnormalities (failure, 60% of patients)—autoimmune ovarian failure (Blizzard syndrome), gonadal dysgenesis, pure gonadal dysgenesis, 45,XO (Turner syndrome, 43% of patients), 46,XY gonadal dysgenesis (Swyer syndrome), 46,XX q5 X chromosome long-arm deletion, mixed or mosaic, follicular depletion, autoimmune disease, infection (eg, mumps), infiltrative disease processes (eg, tuberculosis, galactosemia), iatrogenic ovarian failure (eg, alkylating chemotherapy, irradiation), ovarian insensitivity syndrome (resistant ovary [Savage] syndrome), 17α-hydroxylase deficiency, polycystic ovary syndrome (PCOS, 7%), chronic anovulation of pubertal onset. Extragonadal anomalies (40%)—congenital absence of uterus and vagina (15%; Müllerian agenesis), constitutional delay, imperforate hymen, male pseudohermaphroditism (testicular feminization/androgen insensitivity syndrome), pituitary–hypothalamic dysfunction, transverse vaginal septum.

• Risk Factors: None known.

Signs and Symptoms

• No period by the age of 13 years with no secondary sex changes

• No period by the age of 15 years regardless of secondary sex changes

• No period by 2 years after the start of secondary sex changes

Evaluation should not be delayed any time there is the suggestion of a chromosomal abnormality or an obstructed genital tract.

Diagnostic Approach