What labs should be drawn for a comprehensive female hormone workup?

Female Hormone Workup: Essential Laboratory Tests

For a comprehensive female hormone workup, draw morning (8 AM) samples including FSH, LH, estradiol, progesterone, TSH, free T4, prolactin, and testosterone, with timing adjusted to the early follicular phase (cycle days 2-5) in menstruating women. 1

Core Hormone Panel

Gonadal Axis Assessment

• FSH and LH: These gonadotropins must be measured together with estradiol to distinguish primary ovarian failure (high FSH/LH with low estradiol) from central hypogonadism (low FSH/LH with low estradiol) 1, 2
• Estradiol: Essential for evaluating ovarian function and interpreting gonadotropin levels 1, 2
• Progesterone: Indicates luteal phase function and ovulation when elevated in the mid-luteal phase 3
• Testosterone: Should be included as part of comprehensive hormonal assessment, particularly in patients with symptoms of androgen excess or deficiency 1

Thyroid Function

• TSH and free T4: Critical components of any hormonal workup, as thyroid dysfunction commonly affects reproductive function 1, 2

Pituitary Function

• Prolactin: Elevated levels can suppress gonadotropin secretion and cause menstrual irregularities 1
• ACTH and morning cortisol: Include when evaluating for broader pituitary dysfunction or in patients with fatigue, though not routinely required for basic reproductive assessment 1, 2

Critical Timing Considerations

Menstrual Cycle Timing

• Early follicular phase (days 2-5): Optimal timing for baseline FSH, LH, and estradiol in menstruating women 1, 3
• Mid-luteal phase (days 21-23 of 28-day cycle): Best timing for progesterone to confirm ovulation 3
• Morning collection (around 8 AM): Essential for accurate ACTH, cortisol, and optimal for gonadotropins and sex hormones 1

Special Populations

• Amenorrheic women: Can be tested at any time, but morning collection remains important 1
• Postmenopausal women: Cycle timing irrelevant, but morning collection still preferred 1
• Women on hormonal contraception: Cannot reliably assess ovarian function while on treatment; must discontinue and wait for axis recovery before testing 2

Clinical Context for Interpretation

Pattern Recognition

• LH:FSH ratio >2: Characteristic of polycystic ovary syndrome (PCOS) when measured in follicular phase 1
• LH:FSH ratio <1: Typical of functional hypothalamic amenorrhea in approximately 82% of cases 1
• Elevated FSH with low estradiol: Indicates primary ovarian insufficiency or failure 2, 1
• Low FSH/LH with low estradiol: Suggests central (hypothalamic-pituitary) dysfunction 1, 2

Symptom-Directed Testing

• Fatigue, loss of libido, mood changes: Warrant full gonadal axis evaluation (FSH, LH, estradiol) plus thyroid function 1, 2
• Menstrual irregularities: Require FSH, LH, estradiol, progesterone, TSH, and prolactin 2, 1
• Suspected premature ovarian failure: FSH, LH, estradiol, with consideration of anti-Müllerian hormone (AMH) for ovarian reserve assessment 2

Common Pitfalls to Avoid

Technical Errors

• Single time-point measurements: Avoid drawing hormones at random times without considering menstrual cycle phase, as this leads to misinterpretation 1
• Afternoon sampling: Particularly problematic for cortisol and testosterone, which show significant diurnal variation 1
• Testing during hormonal contraception: Suppresses the hypothalamic-pituitary-ovarian axis and prevents accurate assessment of endogenous function 2

Interpretation Errors

• Assuming menstruation equals fertility: Regular cycles do not guarantee normal ovarian reserve, particularly in women with history of gonadotoxic exposures 2
• Isolated hormone interpretation: FSH and LH must always be interpreted in context with corresponding sex hormones (estradiol or testosterone) 1, 2
• Ignoring clinical context: Hormone levels vary widely throughout the cycle and between individuals; reference ranges must be phase-specific 3, 4

Additional Considerations for Specific Scenarios

Cancer Survivors or Immunotherapy Patients

• Expanded pituitary assessment: Include ACTH, cortisol, TSH, free T4, FSH, LH, estradiol, and prolactin when central endocrinopathy suspected 1, 2
• Baseline before treatment: Establish pre-treatment hormone levels in patients receiving potentially gonadotoxic therapy 2
• Bone density assessment: Consider in hypogonadal patients due to increased fracture risk 2

Fertility Evaluation

• Anti-Müllerian hormone (AMH): Emerging marker for ovarian reserve that doesn't vary by menstrual cycle day and correlates well with antral follicle count 2
• Day 3 FSH and estradiol: Traditional markers of ovarian reserve, though AMH may be superior 2