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Male infertility
Evaluation of male infertility starts with history, examination and two semen analyses; in azoospermia obstructive (normal FSH, normal testicular volume) is told from non-obstructive (high FSH, small testes), and in the non-obstructive type a karyotype and Y-chromosome microdeletion testing are sent.
Why it matters in the exam
Infertility is defined as no pregnancy after 12 months of unprotected intercourse, and a male factor contributes to about half of cases. WHO 2021 lower reference limits: volume 1.4 mL, concentration 16 million per mL, total sperm 39 million, total motility 42 percent, progressive motility 30 percent, normal forms 4 percent and vitality 54 percent. The sample is taken after 2 to 7 days of abstinence, and at least two analyses are done. It is important to ask about exogenous testosterone and anabolic steroids — they suppress sperm production and must be stopped.
In obstructive azoospermia sperm production is normal: normal FSH, normal testicular volume. Congenital bilateral absence of the vas deferens (CBAVD) — impalpable vasa, low-volume acidic semen — is linked to CFTR mutations, and both partners need testing. Low volume with palpable vasa suggests ejaculatory duct obstruction. In non-obstructive azoospermia: high FSH, small testes; send a karyotype (Klinefelter is the commonest genetic cause) and Y microdeletion testing — complete deletion of AZFa or AZFb predicts that no sperm will be found, whereas in AZFc sperm can sometimes be found. Genetic tests are also recommended in severe oligospermia (by AUA below 1 million per mL, by EAU below 5 million).
Treatments: repair of a clinical varicocele in a man with abnormal semen; microsurgical testicular sperm extraction (micro-TESE) with intracytoplasmic sperm injection (ICSI) in non-obstructive azoospermia; epididymal or testicular sperm retrieval, or surgical reconstruction, in obstruction. Hypogonadotropic hypogonadism (low FSH and LH) is treated with hCG and sometimes FSH — not with testosterone. Retrograde ejaculation (after prostate surgery, diabetes or alpha-blockers) is diagnosed by sperm in post-ejaculatory urine. An infertile man is at higher risk of testicular cancer and general illness, so the physical examination matters.
Key points
- Infertility = 12 months without pregnancy.
- WHO 2021: concentration 16 million per mL, normal forms 4 percent.
- High FSH — non-obstructive; karyotype and Y deletions.
- CBAVD — CFTR.
- Exogenous testosterone suppresses sperm.
Summary table
| Type | FSH | Testicular volume | Evaluation or treatment |
|---|---|---|---|
| Obstructive azoospermia | Normal | Normal | CBAVD — CFTR testing; sperm retrieval or reconstruction |
| Non-obstructive azoospermia | High | Small | Karyotype and Y deletions; micro-TESE with ICSI |
| Hypogonadotropic hypogonadism | Low | Small | hCG and sometimes FSH |
| Varicocele with abnormal semen | Normal or slightly high | Sometimes small on the left | Microsurgical repair |
| Retrograde ejaculation | Normal | Normal | Sperm in post-ejaculatory urine |
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Sources
- AUA/ASRM Guideline: Diagnosis and Treatment of Infertility in Men, 2020 — Evaluation and treatment
- WHO Laboratory Manual for the Examination and Processing of Human Semen, 6th edition (2021) — Reference limits
- EAU Guidelines on Sexual and Reproductive Health, 2025 edition — Male infertility
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.