Azoospermia — No Sperm in the Ejaculate
Zero sperm on repeat semen analysis defines azoospermia.
- ~10%: Men affected infertile (have azoospermia)
- ~40%: Obstructive cases (blockage, normal production)
- ~60%: Non-obstructive cases (impaired sperm production)
- 2: Semen analyses required (to confirm diagnosis)
Obstructive vs non-obstructive
A blocked duct differs from failed sperm production.
Obstructive cases usually retrieve sperm easily.
Why ejaculate testing fails
Centrifuged semen pellet is checked for any sperm.
Next step after diagnosis
Surgical retrieval bypasses the ejaculate entirely.
TESE — Testicular Sperm Extraction
Small tissue pieces are removed and searched under a microscope.
- 30–60: Procedure duration (minutes typical)
- 3–6: Tissue samples taken (per testicle)
- ~95%: Obstructive success rate (sperm found)
- ~30–50%: Non-obstructive success (standard TESE)
How tissue is sampled
Small incisions remove seminiferous tubule fragments.
Lab search process
Embryologists mince tissue and scan for motile sperm.
Standard TESE scans broadly at lower magnification.
When standard TESE falls short
Patchy sperm production can be missed entirely.
Micro-TESE — High-Magnification Search
An operating microscope targets the widest, most promising tubules.
- 20–25×: Magnification used (operating microscope)
- ~50–60%: Success in hard cases (vs ~30% standard)
- Less: Tissue removed (than conventional TESE)
- Lower: Complication rate (more selective dissection)
Selecting the best tubules
Wider, opaque tubules more often contain sperm.
Precision over volume
Fine dissection finds focal sperm pockets standard TESE misses.
Micro-TESE roughly doubles retrieval in severe cases.
Trade-offs of the technique
It takes longer and needs specialized training.
Sperm Retrieved and Isolated
Viable sperm are extracted from tissue and prepared for ICSI.
- 1 per egg: Sperm needed (ICSI requires very few)
- Yes: Cryopreservation option (freeze for later cycles)
- Motility, morphology: Quality graded by (lab assessment)
- Same day: Time to ICSI use (or frozen cycle)
Isolating viable sperm
Motile sperm are pipetted away from tissue debris.
Grading retrieved sperm
Quality score reflects motility and shape together.
Even a few sperm can be enough for ICSI.
Storage and backup
Extra sperm are frozen for future attempts.
Predicting ICSI Fertilization Success
Retrieved sperm quality and quantity forecast fertilization rate.
- 40–75%: Fertilization rate range (with retrieved sperm)
- Similar: TESE vs ejaculated sperm (ICSI outcomes)
- Sperm quality: Key predictor (more than count)
- ~30–40%: Live birth per cycle (varies by cause)
What predicts fertilization
Motility and morphology outweigh raw sperm count.
Technique and cause combine
Better retrieval technique raises expected fertilization rate.
Micro-TESE plus good grading improves ICSI odds most.
Beyond fertilization
Embryo development still depends on the egg too.