Evaluation and Management of Primary Amenorrhea

Definition and Diagnosis

Primary amenorrhea is defined as no menarche by age 15 years, or by age 13 years in the absence of secondary sexual characteristics, according to the British Journal of Sports Medicine 2
The American College of Obstetricians and Gynecologists recommends initial evaluation to include a thorough history focusing on growth and development patterns, nutritional status and weight changes, exercise habits, and psychological stressors 1
The initial evaluation should also assess for excessive exercise, which can contribute to primary amenorrhea, as noted by the British Journal of Sports Medicine 4

First-line laboratory tests should include pregnancy test, FSH and LH levels, prolactin level, and TSH level to differentiate between hypothalamic, pituitary, and ovarian causes, as recommended by Praxis Medical Insights 3
Pelvic ultrasound is recommended to assess uterine and ovarian anatomy, identify structural abnormalities, and evaluate endometrial thickness, according to Praxis Medical Insights 1
The presence of polycystic ovarian morphology (≥20 follicles of 2-9mm per ovary or ovarian volume >10ml) can be detected by pelvic ultrasound, as defined by the Human Reproduction Update 5

Athletes with primary amenorrhea require evaluation for Relative Energy Deficiency in Sport (RED-S), as recommended by the British Journal of Sports Medicine 4
Patients with hypothalamic amenorrhea should be evaluated for eating disorders, according to Praxis Medical Insights 1
DXA scan for bone mineral density assessment is recommended for patients with amenorrhea lasting >6 months, history of eating disorders, or BMI <18.5 kg/m², as recommended by Praxis Medical Insights 3