What tests are used to evaluate ovarian function?

Ovarian Function Tests

The most reliable tests for evaluating ovarian function include follicle-stimulating hormone (FSH), estradiol, anti-Müllerian hormone (AMH), and antral follicle count (AFC) by transvaginal ultrasound, with AMH and AFC being the most accurate markers of ovarian reserve. 1

Primary Diagnostic Tests

Hormonal Assessments

• Anti-Müllerian Hormone (AMH): Considered the most reliable marker for assessing ovarian reserve as it correlates well with antral follicle count and is better than age, basal FSH, and estradiol in predicting ovarian reserve 1

  • AMH does not vary throughout the menstrual cycle and is not affected by hormonal contraceptives or hormone replacement therapy 1
  • AMH levels decline with age, with significant drops beginning around age 30 2
  • Low AMH levels (<8.1 pmol/L) predict poor ovarian response during IVF with 80% sensitivity and 85% specificity 2

• Follicle-Stimulating Hormone (FSH): Should be measured during the early follicular phase (days 2-3 of menstrual cycle) 1

  • Elevated FSH levels indicate diminished ovarian reserve 1
  • FSH is less reliable than AMH as it can vary throughout the menstrual cycle 2, 3

• Estradiol: Should be measured alongside FSH during the early follicular phase 1

  • Helps interpret FSH results, as normal FSH with elevated estradiol may mask diminished ovarian reserve 1

Imaging Studies

• Transvaginal Ultrasound (TVUS): Primary imaging modality for ovarian assessment 1

  • Antral Follicle Count (AFC): Count of follicles 2-9 mm in diameter
    • Strong positive correlation with AMH levels 4, 3
    • When AFC <5 and ovarian volume <3 cm³, this suggests diminished ovarian reserve 1
  • Ovarian Volume: Measured during TVUS; volume <3 cm³ suggests diminished reserve 1

• Transabdominal Ultrasound: Secondary option when transvaginal approach is not feasible 1

  • Less reliable for accurate follicle counts due to lower transducer frequency 1

• MRI Pelvis: Alternative when ovaries cannot be adequately visualized by ultrasound 1

  • T2-weighted MRI can determine antral follicle counts and may be superior to TVUS for detecting follicles <3 mm 1

Clinical Applications and Interpretation

Assessment of Premature Ovarian Insufficiency (POI)

• For patients with suspected POI, evaluate:
  • Menstrual history and pattern (irregular cycles or amenorrhea) 1
  • FSH and estradiol levels during early follicular phase 1
  • AMH levels (very low levels indicate ovarian failure) 1
  • AFC via transvaginal ultrasound 1

Evaluation of Polycystic Ovary Syndrome (PCOS)

• Diagnostic criteria for polycystic ovarian morphology (PCOM) include:
  • ≥25 follicles (2-9 mm in diameter) in at least one ovary 1
  • Ovarian volume >10 mL 1
  • Note: Imaging findings alone are insufficient for PCOS diagnosis and must be combined with clinical features 1

Age-Related Considerations

• AMH and AFC show stronger negative correlation with age (rs=-0.67 and rs=-0.55, respectively) than FSH (rs=0.38) 4
• In women under 35, AMH and AFC are the most reliable predictors of ovarian reserve 4, 5
• In women over 42, FSH may be more valuable even with abnormally low AMH 5

Special Considerations

Monitoring Cancer Survivors

• Female cancer survivors treated with gonadotoxic therapies should undergo regular ovarian function assessment 1
• Higher risk in patients treated with:
  • Alkylating agents 1
  • Cyclophosphamide and procarbazine 1
  • Radiotherapy potentially exposing the ovaries 1

Pitfalls in Testing

• FSH is not a reliable marker of menopausal status in women with prior chemotherapy, pelvic radiation exposure, or those on tamoxifen 1
• AMH interpretation requires age-specific reference ranges 4, 2
• Discordances between FSH and AMH can occur and have clinical significance:
  • Normal AMH with abnormal FSH generally predicts better outcomes than normal FSH with abnormal AMH in women under 42 5
  • Both tests should be interpreted together for comprehensive assessment 5