Why is hormone analysis essential in the infertility work‑up for women of reproductive age, and what initial hormone panel should be ordered?

Female Hormone Analysis in Infertility Evaluation

Hormone analysis is essential in the infertility work-up because it identifies ovulatory dysfunction, assesses ovarian reserve, and detects endocrine disorders that directly impact fertility—all of which guide treatment decisions and predict reproductive outcomes. 1, 2

Why Hormone Testing is Critical

Hormone analysis serves multiple essential functions in the infertility evaluation:

• Confirms ovulatory function: Approximately 20-35% of female infertility cases involve ovulatory disorders, making hormonal assessment crucial for diagnosis 3
• Assesses ovarian reserve: Determines the quantity of remaining oocytes and helps predict response to fertility treatments 1, 4
• Identifies treatable endocrine disorders: Detects conditions like thyroid dysfunction (affecting fertility), hyperprolactinemia (20% of secondary amenorrhea cases), and PCOS (most common endocrine disorder in reproductive-aged women) 1, 3
• Predicts treatment outcomes: Hormone levels correlate with live birth rates and help determine appropriate treatment intensity 5

Initial Hormone Panel to Order

The essential first-line hormone panel should include:

Day 3 Testing (Early Follicular Phase)

• FSH and estradiol: Measured on cycle day 3 to assess baseline ovarian reserve 6, 7
  • FSH >13 mIU/mL or estradiol >80 pg/mL suggests diminished ovarian reserve 7
  • These values predict poor response to ovarian stimulation and lower pregnancy rates 7

Cycle-Independent Testing

• Anti-Müllerian hormone (AMH): Can be measured on any day of the cycle as it does not vary with menstrual phase and is unaffected by exogenous hormones 1, 6

  • AMH correlates with antral follicle count and is superior to FSH, estradiol, and inhibin B for assessing ovarian reserve 1, 4
  • Very low AMH indicates ovarian failure; however, AMH reflects oocyte quantity, not quality 4
  • Age combined with AMH ≥10 pmol/L has nearly 90% predictive value for live birth 5

• TSH (thyroid-stimulating hormone): Essential screening as thyroid disorders directly affect fertility 1, 2

  • TSH ≤2.5 mIU/L combined with age and ovulatory status predicts live birth with ~90% accuracy 5

• Prolactin: Indicated if there is galactorrhea, menstrual irregularity, or clinical suspicion of hyperprolactinemia 3, 2

  • A single measurement at any time of day is sufficient 3

Mid-Luteal Phase Testing (Days 21-23 of 28-day cycle)

• Progesterone: Confirms ovulation occurred 1, 2
  • Progesterone ≥25 nmol/L (approximately 8 ng/mL) indicates ovulation 8, 5
  • However, progesterone alone can miss subtle ovulatory defects like luteinized unruptured follicle syndrome 8

Special Timing Considerations

For women with irregular cycles:

• If amenorrhea is present: Measure FSH, LH, and estradiol randomly 6
• If oligomenorrhea: Test during early follicular phase (days 2-5) if possible 6
• Results must be interpreted cautiously due to menstrual irregularities 6

Critical timing pitfall: Hormone levels should be assessed after discontinuing oral contraceptives or hormone replacement therapy, ideally after two months without these medications, as they suppress endogenous hormone production and mask underlying dysfunction 6

Clinical Algorithm for Hormone Testing

Step 1: Initial Assessment

• Order day 3 FSH and estradiol, plus TSH and AMH (any day) 6, 2
• Add prolactin if galactorrhea, irregular cycles, or clinical suspicion 3

Step 2: Mid-Luteal Confirmation

• Measure progesterone on day 21-23 to confirm ovulation 1, 5

Step 3: Interpretation and Action

• Normal ovarian reserve (FSH <13 mIU/mL, E2 <80 pg/mL, normal AMH): Proceed with standard fertility evaluation 7
• Diminished ovarian reserve (elevated FSH/E2, low AMH): Counsel on shortened reproductive window and consider more aggressive treatment 4, 7
• Anovulation (progesterone <25 nmol/L): Investigate cause with additional testing (LH, androgens if PCOS suspected) 2, 5
• Thyroid dysfunction or hyperprolactinemia: Treat underlying disorder before fertility interventions 1, 5

Common Pitfalls to Avoid

• Don't rely on single progesterone measurement alone: Multiple progesterone determinations or ultrasound correlation may be needed, as 20% of cycles with progesterone >25 nmol/L may still have ovulatory defects like luteinized unruptured follicle 8
• Don't ignore serial FSH variability: In women of advanced reproductive age (≥38 years), 29% show shifts from normal to abnormal FSH/E2 values within two years, and once elevated, these remain persistently abnormal 7
• Don't misinterpret AMH in specific contexts: Low FSH from hypogonadotropic hypogonadism or hormonal contraceptive use may artificially lower AMH without reflecting true ovarian reserve 4
• Don't use AMH as sole predictor: AMH indicates oocyte quantity but not quality or pregnancy chances—age remains the strongest predictor of fertility treatment success 4
• Don't delay evaluation in women >35 years: Earlier assessment is justified after only 6 months of unprotected intercourse rather than the standard 12 months 1, 6

Additional Considerations for Specific Populations

Women with history of cancer treatment:

• AMH is particularly useful as it shows promise for predicting ovarian reserve and timing of menopause after gonadotoxic therapy 1
• AMH levels decrease in both adult and pediatric cancer patients, with potential recovery after low-dose alkylating chemotherapy 1

Women with PCOS features:

• Transvaginal ultrasound showing ≥25 follicles (2-9 mm) or ovarian volume >10 mL supports PCOS diagnosis when combined with clinical criteria 1
• Androgen profile should be added if PCOS is suspected 3