Praxis Medical Insights

Est. 2024 • Clinical Guidelines Distilled

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Last Updated: 2/11/2026

Guideline for Female Reproductive Hormone Testing

Core Hormone Panel

  • The essential panel for evaluating female reproductive function includes FSH, LH, estradiol, prolactin, TSH, and free T4 measured on cycle days 3‑6; testosterone, progesterone, and AMH are added based on clinical presentation. 1

Gonadotropin Assessment (FSH & LH)

  • Samples should be taken in the early follicular phase (days 3‑6) with three measurements 20 minutes apart and averaged for optimal accuracy. 2
  • Elevated FSH > 25‑35 IU/L with low estradiol < 20‑50 pg/mL indicates ovarian insufficiency or premature ovarian failure. 1
  • LH/FSH ratio > 2 is suggestive of polycystic ovary syndrome (PCOS). 2
  • Low or low‑normal LH and FSH < 10 IU/L together with low estradiol points to functional hypothalamic amenorrhea or central hypogonadism. 3

Estradiol (E2) Interpretation

  • Estradiol should be measured on days 3‑6; single values have limited value, but persistently low estradiol < 20 pg/mL is most clinically significant. 3
  • Estradiol < 50 pg/mL with elevated FSH/LH confirms ovarian insufficiency. 4
  • Estradiol < 50 pg/mL with low‑normal FSH/LH suggests functional hypothalamic amenorrhea. 3
  • Estradiol > 150 pg/mL may reflect a mid‑cycle surge or an estradiol‑secreting ovarian cyst. 5

Prolactin Evaluation

  • Morning resting prolactin (fasting, non‑postictal) is required. 2
  • Prolactin > 20‑25 µg/L (or > 100 ng/mL for marked elevation) indicates hyperprolactinemia causing anovulation and amenorrhea. 1
  • When hyperprolactinemia is identified, pituitary adenoma, hypothyroidism, and medication effects must be excluded. 2

Thyroid Function Assessment (TSH & Free T4)

  • Thyroid testing is part of the initial reproductive work‑up. 1
  • Elevated TSH with low/low‑normal free T4 denotes primary hypothyroidism, which can disrupt menstrual cycles. 1
  • Low TSH with high free T4 indicates hyperthyroidism. 1
  • Normal or mildly elevated TSH with low free T4 may represent central hypothyroidism secondary to pituitary disease. 6

Progesterone (Mid‑Luteal)

  • Progesterone measured 7 days before expected menses (mid‑luteal phase) is used to assess ovulation. 2
  • Progesterone < 1‑6 nmol/L signifies anovulation. 1

Androgen Assessment (Testosterone & DHEA‑S)

  • Total testosterone should be measured on days 3‑6 in women with hirsutism, virilization, or suspected PCOS. 2
  • Testosterone > 2.5 nmol/L (or elevated free testosterone) supports a diagnosis of PCOS or adrenal hyperandrogenism. 7
  • Total testosterone is generally more reliable than free testosterone; both should be measured with gold‑standard assays. 4
  • DHEA‑S age‑specific thresholds (> 3800 ng/mL for ages 20‑29; > 2700 ng/mL for ages 30‑39) suggest an adrenal source of excess androgens. 2
  • DHEA‑S > 600 µg/dL raises concern for an adrenal tumor. 7

17‑Hydroxyprogesterone (17‑OHP)

  • A fasting 8 AM 17‑OHP level is obtained when non‑classic congenital adrenal hyperplasia (CAH) is suspected. 1
  • Elevated 17‑OHP screens for 21‑hydroxylase deficiency (non‑classic CAH). 8

Anti‑Müllerian Hormone (AMH)

  • AMH is measured as an indicator of ovarian reserve. 1
  • AMH < 0.5‑1 ng/mL indicates diminished ovarian reserve or ovarian insufficiency. 7
  • Normal or elevated AMH assists in the diagnosis of PCOS. 7
  • AMH reflects the total follicle pool and the rate of follicle loss. 5

Technical & Timing Considerations

  • Discontinue combined hormonal contraception or antigonadotropic progestins at least 3 months before testing to avoid suppressed FSH results. 5
  • Avoid post‑ictal prolactin sampling in women with epilepsy. 2
  • Repeat abnormal FSH results after 1 month to confirm borderline elevations (FSH 25‑35 IU/L). 5
  • Assay methods vary between laboratories; clinicians should be familiar with local reference ranges. 7

Diagnostic Patterns by Condition

Functional Hypothalamic Amenorrhea

  • LH < 10 IU/L, FSH < 10 IU/L (LH/FSH ≈ 1), estradiol < 50 pg/mL, progesterone < 1 ng/mL, AMH > 1 ng/mL. 7

Ovarian Insufficiency / Menopause

  • LH > 15 IU/L, FSH > 15 IU/L (FSH > LH), estradiol < 50 pg/mL, progesterone < 1 ng/mL, AMH < 0.5 ng/mL. 5

Polycystic Ovary Syndrome (PCOS)

  • LH < 15 IU/L, FSH < 10 IU/L (LH > FSH), estradiol < 50 pg/mL, progesterone < 1 ng/mL, AMH normal or elevated, testosterone elevated. 8

Hyperprolactinemia

  • LH < 10 IU/L, FSH < 10 IU/L (LH < FSH), estradiol < 50 pg/mL, progesterone < 1 ng/mL, prolactin elevated. 7

Thyroid Dysfunction and Hormonal Evaluation in Menstrual Irregularities

Laboratory Assessment

  • Thyroid dysfunction (abnormal TSH or free T4) is a common, reversible cause of menstrual irregularity, therefore thyroid function testing should be included in the work‑up of patients with abnormal estradiol and gonadotropin patterns. 9

  • A comprehensive hormonal panel—including prolactin, TSH, free T4, and β‑hCG—should be obtained to exclude alternative etiologies (e.g., hyperprolactinemia, thyroid disease, pregnancy) when evaluating markedly elevated estradiol with discordant gonadotropins. 9

Evaluation and Management of Adolescent Amenorrhea

Diagnostic Evaluation

  • Adolescents presenting with ≥5 months of amenorrhea should undergo a pelvic examination and a comprehensive hormonal panel—including FSH, LH, estradiol, prolactin, TSH, free T4, and β‑hCG—to distinguish functional hypothalamic amenorrhea, primary ovarian insufficiency, polycystic ovary syndrome, and structural abnormalities. 10

  • Amenorrhea in the adolescent population is considered a specific indication for performing a pelvic examination. 10

REFERENCES

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