The simple idea (no memorising)
Always begin with the least invasive test: a semen analysis. Never jump to biopsies first. If it's abnormal, sort the cause into three levels:
- Pre‑testicular — the testis is fine, but the signals are missing. (Brain/pituitary not sending FSH/LH.)
- Testicular — the testis itself is damaged (genetic problems, past mumps, injury, chemotherapy).
- Post‑testicular — sperm are made but can't get out (a blockage, or a delivery problem).
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The hormone echo of Concept 2
Remember: FSH → Sertoli cells → sperm support; LH → Leydig cells → testosterone. So:
- if the brain isn't signalling, FSH/LH are low;
- if the testis has failed, FSH swings high (the brain shouts louder at a testis that won't answer).
The vocabulary (easy once you see the roots)
- Azoospermia — no sperm in the semen.
- Oligozoospermia — few sperm.
- Asthenozoospermia — poorly moving sperm.
- Teratozoospermia — abnormally shaped sperm.
Two practical pearls
- A varicocele (varicose veins around the testis — a "bag of worms") can lower sperm quality, but finding one doesn't automatically make it the cause.
- Taking testosterone (e.g. gym supplements) to "boost" fertility actually backfires — it switches off the brain's FSH/LH and suppresses the man's own sperm production. A crucial, counter‑intuitive point. 🚩
Why it matters
Starting with the man is quick, cheap and comfortable — and it often finds the answer fast, sparing the woman unnecessary tests.
Quick check ✅
- What is the first investigation of the male partner?
- Why can taking testosterone worsen a man's fertility?
Remember this 🌟
Where we're going next → Now the woman's side — the first question is always the same. Concept 31.