Micro-TESE is an operation that uses an operating microscope to search testicular tissue for small areas that may be producing sperm. It is mainly used for non-obstructive azoospermia. Finding sperm is not guaranteed, and any sperm retrieved normally need to be used with ICSI. Assessment, genetic testing and a clear contingency plan should come before surgery.

What is micro-TESE?

Micro-TESE stands for microscopic testicular sperm extraction. A specialist surgeon opens the testicle through a small scrotal incision and uses an operating microscope to identify seminiferous tubules that look more likely to contain sperm. Small tissue samples are passed to the laboratory and examined during the procedure.

The aim is to find sperm while limiting unnecessary removal of testicular tissue. If suitable sperm are found, they may be used immediately with eggs or frozen for later IVF with intracytoplasmic sperm injection, known as ICSI.

Micro-TESE is a sperm-retrieval procedure. It does not treat the underlying cause of reduced sperm production and does not restore sperm to the ejaculate.

Who might be offered micro-TESE?

Micro-TESE is mainly considered for non-obstructive azoospermia. This means no sperm are found in the ejaculate because sperm production in the testicles is severely impaired or absent, rather than because sperm are being produced but blocked from reaching the semen.

The 2026 NICE fertility guideline says to offer surgical sperm retrieval for non-obstructive azoospermia and to consider micro-TESE when carrying it out. NICE describes the evidence comparing retrieval techniques as limited and low quality, but notes that micro-TESE is the preferred method in clinical practice for this group.

Other retrieval techniques may be more appropriate for obstructive azoospermia. The diagnosis needs to be established before choosing a procedure.

What is the difference between obstructive and non-obstructive azoospermia?

• Obstructive azoospermia: Sperm production may be relatively preserved, but a blockage prevents sperm entering the ejaculate
• Non-obstructive azoospermia: Sperm production within the testicles is severely reduced or absent
• Obstructive azoospermia: Causes can include vasectomy, congenital absence of the vas deferens, infection or injury
• Non-obstructive azoospermia: Causes can include genetic conditions, previous chemotherapy, testicular damage, undescended testicles or unexplained testicular failure
• Obstructive azoospermia: Reconstruction or less extensive sperm-retrieval methods may be options
• Non-obstructive azoospermia: Micro-TESE may be considered to search for small areas of sperm production

A semen report saying “no sperm seen” is the starting point, not the complete diagnosis. A repeat analysis and specialist assessment are needed.

What assessment should happen before micro-TESE?

A thorough assessment helps confirm the diagnosis, identify conditions that change the treatment plan and avoid an operation when sperm retrieval is not appropriate.

It may include:

• At least two appropriately processed semen analyses confirming azoospermia
• Medical, surgical and reproductive history
• Examination of the testicles, scrotum and vas deferens
• Testosterone, follicle-stimulating hormone and luteinising hormone tests
• Karyotype testing
• Y-chromosome microdeletion testing
• CFTR testing when obstruction or an absent vas deferens is suspected
• Scrotal ultrasound when clinically indicated
• Review of previous chemotherapy, surgery, infection, testosterone or anabolic-steroid use
• Assessment of the partner providing eggs and the wider IVF plan

The 2026 NICE guideline recommends Y-chromosome microdeletion testing for unexplained azoospermia and karyotype testing for unexplained azoospermia. It says not to offer surgical sperm retrieval when an AZFa or AZFb Y-chromosome microdeletion is present because the chance of retrieval is extremely low.

Genetic counselling should be offered when a relevant genetic condition is identified. Some findings may be passed to a male child, so the implications extend beyond whether sperm can be found.

Can tests predict whether micro-TESE will find sperm?

No available test can provide certainty. Hormone levels, testicular volume, diagnosis, genetics, previous surgery and tissue findings may help a specialist discuss probability, but they do not produce a reliable yes-or-no prediction for every man.

Be cautious about a single percentage quoted without context. Published sperm-retrieval rates vary because studies include different diagnoses, surgeons, laboratories, definitions and previous procedures.

Ask whether the clinic’s estimate is based on:

• Men with the same diagnosis and genetic findings
• First-time or repeat micro-TESE procedures
• Retrieval of any sperm or enough usable sperm for ICSI
• Fresh or frozen sperm use
• The surgeon’s and laboratory’s own audited results

Finding sperm is not the same outcome as having a baby. Live birth also depends on egg-related factors, fertilisation, embryo development, transfer and pregnancy.

What happens on the day of surgery?

The exact pathway varies by hospital, but micro-TESE usually involves:

Anaesthetic and preparation

The operation is commonly performed under general anaesthetic. Follow the hospital’s fasting, medication and arrival instructions. Tell the team about blood-thinning medication, allergies, recent illness and any change in your health.

Surgical examination

The surgeon makes an incision in the scrotum and opens the testicle. Using an operating microscope, they inspect the tubules and select small samples from areas that appear more promising.

Laboratory search

An embryologist or andrology scientist processes and examines the tissue for sperm. The surgeon and laboratory may communicate during the operation so that sampling can stop when usable sperm are found or continue according to the agreed limits.

Closure and recovery

The surgeon closes the testicular and scrotal layers. You are monitored while the anaesthetic wears off and may be discharged the same day or after an overnight stay, depending on the service and your recovery.

Ask before surgery whether one or both testicles may be explored and under what circumstances the team would stop.

What happens if sperm are found?

Sperm found during micro-TESE are generally used with ICSI because the number is small and testicular sperm may not move like ejaculated sperm.

Depending on the treatment plan, sperm can be:

• Used fresh with eggs collected around the same time
• Frozen for a later IVF or ICSI cycle
• Divided between fresh use and storage if enough are found

Freezing is valuable because it may avoid another operation, but not every sperm survives freezing and thawing. Ask how the laboratory decides whether the sample is suitable for storage and whether a test thaw is performed.

Read IVF vs ICSI for the laboratory process.

Should egg collection happen on the same day?

There are two broad strategies:

• Coordinate micro-TESE with egg collection so fresh sperm can be used immediately
• Perform retrieval first and freeze sperm before the partner begins or completes ovarian stimulation

Each has advantages and risks. Coordinating fresh treatment may avoid concern about thawing a very small sample, but eggs may be collected even if no sperm are found. Retrieving and freezing first confirms that sperm are available, but very limited sperm may not survive the freeze-thaw process.

This decision should involve the surgeon, embryology laboratory, fertility clinician and both partners. Agree in advance what will happen to the eggs if no sperm are found, including whether they will be frozen, used with donor sperm if valid prior consent exists, or not fertilised.

What happens if no sperm are found?

The team should prepare you for this possibility before surgery. If no sperm are found, ask:

• Whether tissue examination was complete under the agreed plan
• Whether any additional laboratory assessment is pending
• Whether another retrieval attempt would ever be reasonable
• What the result suggests about the underlying diagnosis
• What follow-up is needed for testosterone and testicular health
• What reproductive options remain

Options may include donor sperm, donor embryos, adoption, fostering or living without children. These are not emotionally equivalent alternatives, and no one should pressure you into deciding immediately after an unsuccessful procedure.

What are the risks of micro-TESE?

Potential risks include:

• Pain, swelling and bruising
• Bleeding or a scrotal haematoma
• Infection
• Anaesthetic complications
• Testicular tissue damage or loss of volume
• Reduced testosterone production, temporarily or persistently
• Failure to find sperm
• A need for further treatment or surgery

NICE found no evidence that micro-TESE increased testicular pain, atrophy, haematoma or infection compared with TESA followed by salvage micro-TESE, but it describes the evidence base as limited. Individual surgical risk still needs to be explained.

Ask how testosterone will be checked after surgery, especially if levels were low beforehand or both testicles are explored.

What is micro-TESE recovery like?

Recovery instructions differ, so follow the surgical team’s plan. You may be advised to:

• Wear supportive underwear
• Use prescribed or recommended pain relief
• Keep the wound clean and dry as directed
• Avoid heavy lifting, strenuous exercise and cycling for a stated period
• Avoid sex and ejaculation until the team says it is safe
• Arrange time away from work based on whether your job is sedentary or physical
• Attend wound, hormone and fertility follow-up

Contact the team urgently for increasing redness, fever, discharge, severe or worsening pain, rapidly increasing swelling, difficulty passing urine or any symptom listed in your discharge instructions.

Do not use someone else’s recovery timetable as a substitute for your own surgeon’s advice.

Can hormones or supplements improve the chance of retrieval?

Hormone treatment is appropriate for some specific diagnoses. NICE recommends gonadotrophin therapy for hypogonadotropic hypogonadism, where inadequate hormonal stimulation is the cause of impaired sperm production.

For men without hypogonadotropic hypogonadism, the 2026 NICE guideline says gonadotrophins or anti-oestrogens should only be considered as part of a clinical trial. It says not to use androgens to treat semen abnormalities.

Do not start testosterone before micro-TESE unless a specialist who understands your fertility goal has recommended it as part of a clear plan. Testosterone taken from outside the body can further suppress sperm production.

Ask for evidence before paying for an unproven “optimisation” protocol or supplements advertised as improving retrieval rates.

Questions to ask your surgeon and embryologist

• Has non-obstructive azoospermia been confirmed on two properly processed samples?
• What is the likely cause in my case?
• Have I had all relevant hormone and genetic tests?
• Why is micro-TESE preferable to another retrieval method for me?
• What is your audited retrieval rate for men with my diagnosis?
• What would make you explore one or both testicles or stop the procedure?
• Will an embryologist examine tissue during the operation?
• Will sperm be used fresh, frozen or both?
• What happens to my partner’s eggs if no sperm are found?
• What are the risks to my testosterone and how will it be monitored?
• What support is available if retrieval is unsuccessful?

The most important thing to remember

Micro-TESE offers some men with non-obstructive azoospermia a chance of finding sperm, but it cannot guarantee retrieval, fertilisation or a baby. Confirm the diagnosis, complete genetic assessment, understand the surgical and hormonal risks, and agree the laboratory and contingency plans before treatment begins.

The original Male Fertility Hub webinar with Dr Pippa Sangster explores retrieval methods, realistic outcomes, risks and recovery. Any statement presented as her personal view should be checked against the recording and approved before publication.

For a wider overview, read Understanding Surgical Sperm Retrieval, or join The Male Fertility Hub community for peer support.

Sources

• NICE guideline NG257: Management of male-factor fertility problems
  https://www.nice.org.uk/guidance/ng257/chapter/Management-of-male-factor-fertility-problems
• NICE guideline NG257: Investigation of fertility problems
  https://www.nice.org.uk/guidance/ng257/chapter/Investigation-of-fertility-problems-and-management-strategies
• NICE guideline NG257: Rationale and impact, including azoospermia and Y-chromosome microdeletions
  https://www.nice.org.uk/guidance/ng257/chapter/Rationale-and-impact
• NICE guideline NG257: ICSI
  https://www.nice.org.uk/guidance/ng257/chapter/Intracytoplasmic-sperm-injection-ICSI
• European Association of Urology: Male infertility guideline
  https://uroweb.org/guidelines/sexual-and-reproductive-health/chapter/male-infertility

This article provides general information and does not replace individual advice from a specialist urologist, andrologist, embryologist or fertility clinician.