What lab tests are recommended for evaluating female hormones?

Laboratory Testing for Female Hormone Evaluation

For evaluating female reproductive hormones, measure FSH, LH, and estradiol on cycle days 1-4 (or day 3 specifically), with progesterone added mid-luteal phase if assessing ovulation; add anti-Müllerian hormone (AMH) when evaluating ovarian reserve.

Core Hormone Panel

Timing of Blood Draw

• Early follicular phase (days 1-4, ideally day 3) is optimal for baseline FSH, LH, and estradiol measurement 1, 2
• FSH values on days 1 or 2 are the best single predictor of ovarian reserve, though the combination of FSH and LH on day 1 provides superior predictive value 2
• Day 3 FSH specifically has become the standard timing in clinical practice 3

Essential Hormones to Measure

Baseline Assessment (Early Follicular Phase):

• FSH (Follicle-Stimulating Hormone): Critical for assessing ovarian reserve and function 1
• LH (Luteinizing Hormone): Essential for evaluating pituitary-ovarian axis 1
• Estradiol: Necessary to interpret FSH levels accurately and assess ovarian function 1, 2

Additional Testing Based on Clinical Context:

• Progesterone: Measure in mid-luteal phase (days +5 to +9 after LH peak, or cycle days 21-23 in a 28-day cycle) to confirm ovulation 3
• Anti-Müllerian Hormone (AMH): Increasingly important for ovarian reserve assessment; advantage is that it does not vary by menstrual cycle day and is not affected by exogenous estrogen or progesterone 1

Special Populations and Contexts

Cancer Survivors at Risk for Ovarian Dysfunction

For patients who received gonadotoxic therapy (chemotherapy, pelvic radiation), screening should include 1:

• Baseline LH, FSH, and estradiol at age 13 years in prepubertal survivors
• Regular monitoring of menstrual history and hormone levels in sexually mature patients
• Consider AMH levels as they show promise for predicting ovarian reserve and timing of menopause, though normative pediatric data remain limited 1

Suspected Hypogonadism or Amenorrhea

Patients with delayed puberty, irregular menses, primary or secondary amenorrhea, or clinical signs of estrogen deficiency should have 1:

• LH, FSH, and estradiol screening
• Bone mineral density testing for confirmed hypogonadal patients
• Endocrinology or gynecology referral for abnormal hormone levels

Central vs. Primary Hypogonadism Differentiation

• Low ACTH with low cortisol indicates secondary (central) adrenal insufficiency, suggesting pituitary pathology 1
• Consider additional pituitary hormones: TSH, free T4, and in specific cases, testosterone (males) or estrogen (premenopausal females with fatigue, loss of libido, oligomenorrhea) 1
• MRI brain with pituitary cuts indicated for multiple endocrine abnormalities 1

Reference Values Across Menstrual Cycle

Understanding normal variation is critical for interpretation 3:

• Early follicular phase (days -15 to -6): Lower FSH and estradiol
• Late follicular phase (days -5 to -1): Rising FSH and estradiol
• LH peak (day 0): Dramatic LH surge
• Mid-luteal phase (days +5 to +9): Peak progesterone, elevated estradiol
• FSH increases with age, particularly in women 40-45 years compared to 20-25 years 2

Key Clinical Pitfalls

Interpretation Errors to Avoid

• Do not interpret FSH in isolation: Elevated estradiol can artificially suppress FSH, masking diminished ovarian reserve 1
• Timing matters critically: FSH measured outside the early follicular phase is unreliable for ovarian reserve assessment 2, 3
• AMH advantages: Unlike FSH and estradiol, AMH does not require specific cycle timing, but very low levels indicate ovarian failure while normal ranges are wide in healthy young women 1

Age-Related Considerations

• Older reproductive age women (40-45 years) show significantly higher FSH, estradiol, and FSH:LH ratios on days 1-4 compared to younger women (20-25 years) 2
• Short cycles in perimenopausal women demonstrate lower estradiol and high FSH throughout, while LH remains normal 4

Laboratory Quality Requirements

While the provided evidence focuses primarily on breast cancer estrogen/progesterone receptor testing 1, the principles of laboratory standardization apply: laboratories should participate in proficiency testing programs and maintain validated assay methods 1.