What is the initial workup for a patient presenting with amenorrhea (absence of menstruation)?

From the Guidelines

The initial workup for a patient presenting with amenorrhea should begin with a thorough history and physical examination, followed by pregnancy testing as this is the most common cause of secondary amenorrhea. If pregnancy is excluded, laboratory evaluation should include thyroid-stimulating hormone (TSH), prolactin, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) levels, as suggested by the most recent study on functional hypothalamic amenorrhea 1. Additional tests may include estradiol levels, complete blood count, comprehensive metabolic panel, and in some cases, a progesterone challenge test to assess estrogen status.

Initial Evaluation

The evaluation process should consider the potential causes of amenorrhea, including hormonal imbalances, anatomical abnormalities, and premature ovarian insufficiency. The study by 1 highlights the importance of considering functional hypothalamic amenorrhea (FHA) as a common underlying condition, especially in cases associated with stress, vigorous exercise, weight loss, and psychological disorders.

Laboratory Tests

Key laboratory tests include:

• Thyroid-stimulating hormone (TSH) to rule out thyroid dysfunction
• Prolactin levels to assess for hyperprolactinemia
• Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels to evaluate ovarian function
• Estradiol levels to assess estrogen status

Imaging Studies

Imaging studies such as pelvic ultrasound may be indicated to evaluate anatomical abnormalities, and brain MRI might be necessary if hyperprolactinemia is detected to rule out pituitary tumors, as suggested by the consensus statement 1.

Consultation

Referral or consultation with an endocrinologist is recommended if the diagnosing physician is not experienced with the treatment of functional hypothalamic amenorrhea or other etiologies of amenorrhea, emphasizing the importance of specialized care in managing amenorrhea 1. Early diagnosis is crucial as amenorrhea can be associated with significant health consequences, including infertility, bone density loss, and increased cardiovascular risk, depending on the etiology.

From the FDA Drug Label

Restoration of menses occurred in 77% of the women treated with cabergoline, compared with 70% of those treated with bromocriptine. The initial workup for a patient presenting with amenorrhea may involve checking prolactin levels, as hyperprolactinemia can cause amenorrhea.

• Key steps in the workup may include:
  • Checking prolactin levels
  • Evaluating for other potential causes of amenorrhea, such as thyroid dysfunction or polycystic ovary syndrome (PCOS)
  • Considering treatment with a dopamine agonist, such as cabergoline, if hyperprolactinemia is diagnosed 2

From the Research

Initial Workup for Amenorrhea

The initial workup for a patient presenting with amenorrhea includes:

• A detailed history to identify potential causes of amenorrhea, such as pregnancy, polycystic ovary syndrome, or hypothalamic amenorrhea 3, 4, 5, 6
• A physical examination to assess for signs of androgen excess, estrogen deficiency, or other endocrinopathies 3, 5, 6
• Laboratory tests, including:
  • Pregnancy test to rule out pregnancy as a cause of amenorrhea 3, 5, 6
  • Serum hormone levels, such as:
    • Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) to evaluate ovarian function 3, 5, 6
    • Prolactin to evaluate for hyperprolactinemia 3, 5, 6, 7
    • Thyroid-stimulating hormone (TSH) to evaluate for thyroid dysfunction 3, 5, 6, 7
  • Other tests, such as karyotyping, serum androgen evaluation, and pelvic or brain imaging, may be individualized based on the patient's presentation and history 6

Evaluation of Amenorrhea

The evaluation of amenorrhea should consider the following categories:

• Outflow tract abnormalities
• Primary ovarian insufficiency
• Hypothalamic or pituitary disorders
• Other endocrine gland disorders
• Sequelae of chronic disease
• Physiologic or induced causes 6 The history and physical examination should guide the selection of laboratory tests and other diagnostic evaluations.

Laboratory Tests

Laboratory tests, such as serum prolactin and TSH levels, can help identify underlying causes of amenorrhea, such as hyperprolactinemia or thyroid dysfunction 3, 5, 6, 7. The results of these tests can inform the selection of additional diagnostic evaluations and guide treatment decisions.