Laboratory Tests to Diagnose Ovarian Failure
The diagnosis of ovarian failure (premature ovarian insufficiency) requires measurement of FSH and estradiol levels on cycle days 2-5 in women with menstrual cycles, or randomly in women with amenorrhea, with elevated FSH (typically >40 mIU/mL) and low estradiol confirming the diagnosis. 1, 2
Essential Diagnostic Laboratory Tests
Primary Hormone Panel
- FSH (Follicle-Stimulating Hormone) is the hallmark marker for diagnosing ovarian failure and must be measured during cycle days 2-5 of the menstrual cycle 1
- For women presenting with amenorrhea, FSH should be measured randomly rather than waiting for a specific cycle day 1
- Estradiol levels must be measured alongside FSH during the early follicular phase, as normal FSH with elevated estradiol may mask diminished ovarian reserve 1
- The diagnosis requires hypoestrogenism with high levels of gonadotropins in women before age 40 2
Additional Hormone Testing
- Prolactin level should be measured to exclude hyperprolactinemia as a cause of amenorrhea 3
- Thyroid-stimulating hormone (TSH) must be checked to rule out thyroid disease, which can cause ovulatory dysfunction and is associated with autoimmune ovarian failure 3, 4
Ovarian Reserve Assessment Tests
Anti-Müllerian Hormone (AMH)
- AMH represents the best endocrine marker for assessing age-related decline in ovarian reserve in healthy women 1
- However, no recommendations exist for using AMH in diagnosing premature ovarian insufficiency, as its diagnostic value remains unestablished 1
- AMH interpretation is most reliable in women ≥25 years where validated normative data exist 5
- The lack of an international standard for AMH limits comparison between different AMH assays 5
Imaging Studies
- Antral follicle count (AFC) by transvaginal ultrasound is the most established method for assessing ovarian reserve, though not part of current clinical criteria for POI 5, 1
- An AFC of <5 and ovarian volume <3 cm³ indicates diminished ovarian reserve 1
- Fifty percent of patients with early POF present with small ovaries (length <2 cm) at ultrasonography 6
Additional Workup to Identify Underlying Causes
Karyotype Analysis
- Karyotype testing should be performed to exclude chromosomal abnormalities (particularly Turner syndrome and variants) in all women diagnosed with premature ovarian failure 2, 4
Autoimmune Screening
- Screen for autoimmune disorders, as 50% of women with occult ovarian failure have autoantibodies to adrenal, thyroid, or ovary 7
- Women with premature ovarian failure should be followed for associated autoimmune endocrine disorders including hypothyroidism, adrenal insufficiency, and diabetes mellitus 4
Critical Testing Limitations and Pitfalls
When FSH Testing is Unreliable
- Do not test FSH in women taking tamoxifen, toremifene, or LHRH agonists/antagonists, as results will be unreliable 1
- FSH is not a reliable marker of menopausal status in women with prior chemotherapy or pelvic radiation exposure 1
- Menopausal status cannot be determined while receiving ovarian function suppression 1
- Avoid testing FSH in women taking oral contraceptives or hormone replacement therapy; ideally wait 2 months after discontinuation 8
Understanding Intermittent Function
- Premature ovarian failure is not premature menopause—half of women with spontaneous POF who have a normal karyotype have ovarian follicles that function intermittently 4, 9
- These women have a 5-10% chance for spontaneous pregnancy despite the diagnosis 4
- A single FSH or estradiol measurement should not be used to counsel women about fertility status, as ovulatory cycles can occur even after postmenopausal hormone levels 8
Clinical Context for Testing
- Laboratory evaluation should be triggered by menstrual changes or POI symptoms rather than used as primary surveillance in asymptomatic at-risk women 1
- At-risk postpubertal females without signs of POI who desire assessment of future fertility should be referred for specialist consultation rather than relying on a single test 5