Female Athlete Triad Workup

Diagnosis of the female athlete triad is largely clinical; no test enables definitive diagnosis. Workup may include laboratory studies (including a pregnancy test), radiography (including dual-energy x-ray absorptiometry [DEXA]), magnetic resonance imaging (MRI) in selected cases, pelvic ultrasonography, bone scanning, electrocardiography (ECG), progesterone challenge, or endometrial biopsy.

Obtain the following laboratory studies in a female suspected of having the female athlete triad:

• Urine or plasma pregnancy test to rule out pregnancy
• Urinalysis with specific gravity to establish volume status
• Complete blood cell (CBC) count to rule out anemia
• Erythrocyte sedimentation rate (ESR) to check for inflammation or infection - A C-reactive protein (CRP) test may be ordered for verification, although this is usually not necessary, because such a clinical problem is likely to have been present for months or years
• Complete metabolic panel to evaluate liver function, electrolyte levels, and kidney function
• Thyroid panel to rule out hyperthyroidism and hypothyroidism - A thyrotropin (ie, thyroid-stimulating hormone [TSH]) test is standard to rule out these diseases, and a free thyroxine (T4) test can be performed to confirm the results; the standard thyroid panel used in most laboratories is now outdated, and the thyrotropin and T4 tests are the standard
• Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) tests to evaluate pituitary function and possible premature ovarian failure
• Prolactin test to evaluate pituitary function
• Testosterone and dehydroepiandrosterone sulfate (DHEAS) tests to evaluate androgen excess and possible adrenal or ovarian tumors - Some forms of these tumors may be nonvirilizing and therefore difficult to diagnose without a laboratory test
• Direct estradiol measurements

If the athlete presents with bone pain, as with a stress fracture, appropriate plain radiographs should be obtained.

Baseline DEXA scans can be obtained in all athletes with the female athlete triad to identify undiagnosed osteoporosis or subclinical stress fractures, as well as to provide a reference for future monitoring.

The American College of Sports Medicine (ACSM) and the American Academy of Pediatrics (AAP) recommend that an athlete’s bone mineral density (BMD) be evaluated if she has been amenorrheic for longer than 1 year, has a body mass index (BMI) lower than 18, or a history of a stress fracture. The recommendation is either a posteroanterior view of the spine or hip if the athlete is older than 20 years or a posteroanterior view of the spine and whole body if the athlete is younger than 20 years, with the diagnosis made on the basis of a Z-score.

If the results of laboratory studies indicate abnormal pituitary function, thin-section MRI of the head should be performed through the sella turcica.

In athletes with primary amenorrhea who lack a uterus (as determined at physical examination), pelvic ultrasonography can be used to verify the finding and to evaluate the presence and morphology of the ovaries. Hand images should also be obtained in these patients to establish their bone age.

When a 3-phase bone scan depicts a stress fracture, further imaging evaluation is usually not indicated. The presence of multiple stress fractures in an at-risk athlete is a warning sign for the female athlete triad.

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A resting ECG should be obtained in any athlete whose resting heart rate is lower than 50 beats/min. Many physicians believe that a baseline ECG should be performed in all athletes at risk for the female athlete triad. As with so many aspects of this disease, exact epidemiologic data are not yet available. Experience with anorexia and bulimia, for which a baseline ECG is usually recommended, suggests that proceeding with this noninvasive test may be a safe choice.

A progesterone challenge test can be used to determine if the uterine endometrium has been primed with estrogen and thus is ready to be shed, as in normal menstruation. A 10-day course of 5 or 10 mg of oral progesterone can be used to induce menstrual bleeding.

Lack of menses indicates that the uterine endometrium has not been adequately exposed to estrogen since the last menses. A positive test result is confirmed when menstrual flow occurs; this finding provides indirect confirmation of the presence of estrogen in amounts sufficient to sustain endometrial growth.

During the workup for amenorrhea, an evaluation of the endometrium may be necessary. The team physician can perform an endometrial biopsy, or a consultation with the primary care physician or gynecologist should be requested.

Endometrial sampling is performed by inserting a thin tube, usually a disposable pipette, through the cervical os into the uterine cavity. Suction is then applied to the tube, and endometrial tissue is drawn into it. This sample is then histologically examined to help determine the stage of growth of the endometrial tissue and, thus, the effects or presence of estrogen and progesterone.