From the Guidelines
A missed period workup should begin with a pregnancy test, as pregnancy is the most common cause of a missed period. If negative, further evaluation includes blood tests for hormonal imbalances, including thyroid function tests (TSH, T3, T4), prolactin levels, follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol, as suggested by 1. These can identify conditions like thyroid disorders, hyperprolactinemia, or premature ovarian insufficiency. A complete blood count should be performed to rule out anemia.
Initial Evaluation
- Pregnancy test
- Blood tests: TSH, T3, T4, prolactin, FSH, LH, estradiol
- Complete blood count
Additional Tests
- Pelvic ultrasound to detect structural abnormalities like polycystic ovary syndrome (PCOS) or uterine fibroids, as recommended by 1
- Testosterone and DHEAS levels for PCOS diagnosis
- Progesterone challenge (medroxyprogesterone acetate 10mg daily for 5-10 days) in cases of prolonged amenorrhea to determine if estrogen levels are adequate
Lifestyle Modifications
- If stress, excessive exercise, or significant weight changes are suspected causes, lifestyle modifications should be recommended, as suggested by 1
Importance of Comprehensive Approach
This comprehensive approach helps identify the underlying cause of missed periods, which is essential for appropriate treatment and to prevent potential long-term health consequences like bone density loss or endometrial hyperplasia, as highlighted by 1 and 1.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Missed Period Workup
The workup for a missed period involves several steps to determine the underlying cause.
- The most common cause of a missed period is pregnancy, which must be ruled out before proceeding with diagnostic evaluation 2, 3.
- A careful history and physical examination may reveal evidence of androgen excess, estrogen deficiency, or other endocrinopathies 2.
- Serum prolactin and thyroid-stimulating hormone (TSH) levels should be checked in all women who are not pregnant 2.
- If serum prolactin and TSH levels are normal, a progesterone challenge test should be performed to determine outflow tract patency and estrogen status 2.
Diagnostic Tests
- Galactorrhea by history or on examination and/or an elevated prolactin level should be investigated with an imaging study to rule out a pituitary adenoma 2.
- In women with hypoestrogenic amenorrhea, indicated by a negative challenge test and a competent outflow tract, serum gonadotropin, follicle-stimulating hormone, and luteinizing hormone levels may be measured to determine whether amenorrhea represents ovarian failure or pituitary or hypothalamic dysfunction 2.
- Thyroid function tests, including TSH, Thyroxine (T4), Triiodothyronine (T3), Iodine, and Thyroid Autoantibodies, should be assessed to evaluate thyroid function 4, 5.
Special Considerations
- Hypothalamic amenorrhea is common in women with a history of weight loss, stress, or vigorous exercise 2.
- Amenorrheic women with adequate estrogen levels should receive cyclic progesterone, and hormonal therapy and calcium supplementation may be necessary in hypoestrogenic amenorrhea 2.
- Thyroid disorders, particularly subclinical hypothyroidism, can affect fertility and pregnancy outcomes, and routine thyroid function testing is recommended by some guidelines 4.