TESA & Micro-TESE Sperm Retrieval at Yaal Fertility Centre, Chennai

This distinction shapes almost every decision that follows an azoospermia diagnosis, so it is worth understanding clearly.

Obstructive azoospermia means the testicles are producing sperm normally, but a blockage somewhere in the reproductive tract prevents that sperm from reaching the ejaculate. Causes include a prior vasectomy, a congenital absence of the vas deferens, scarring from a past infection or surgery, or a blockage at the level of the epididymis. Because sperm production itself is normal, retrieval in obstructive azoospermia is generally more predictable, and a simpler procedure such as TESA is often sufficient to retrieve usable sperm.

Non-obstructive azoospermia means the problem lies in sperm production itself — the testicle is producing very little sperm, or none, often for reasons related to hormonal signalling, genetics, prior injury or treatment such as chemotherapy, or an unidentified cause. Here, any sperm present is likely to exist only in small, scattered pockets of tissue rather than throughout the testicle, which is precisely why a more thorough, microscopically guided search — micro-TESE — gives a meaningfully better chance of finding it than a simpler aspiration.

Determining which category applies uses a combination of hormone levels (particularly FSH), testicular size and ultrasound findings, and sometimes genetic testing, though in some cases the distinction only becomes fully clear at the time of the retrieval procedure itself.

TESA is a relatively brief, minimally invasive procedure in which a fine needle is inserted into the testicle to aspirate a small sample of testicular tissue and fluid, which is then examined in the laboratory for the presence of sperm. It is usually performed under local anaesthesia, sometimes with light sedation, and does not typically require an overnight stay.

Because it does not involve directly visualising testicular tissue under magnification, TESA is best suited to situations where sperm production is expected to be relatively normal and evenly distributed throughout the testicle — most often obstructive azoospermia. Recovery is generally quick, with some soreness or bruising in the days following the procedure that settles with simple measures such as rest and pain relief as advised by your doctor.

Micro-TESE is a more involved surgical procedure, typically performed under general or regional anaesthesia. The testicle is opened and its internal tissue examined directly under an operating microscope, which allows the surgeon to identify the specific seminiferous tubules that appear larger or otherwise more likely to contain active sperm production, rather than sampling tissue blindly.

This matters most in non-obstructive azoospermia, where sperm production, if present at all, tends to be patchy rather than uniform throughout the testicle. By directly visualising and selectively sampling the most promising areas, micro-TESE gives a meaningfully better chance of finding usable sperm than a blind aspiration would, while also allowing the surgeon to remove less tissue overall, which is gentler on the testicle. Recovery takes somewhat longer than after TESA, generally over one to two weeks, with some discomfort, swelling, and bruising that is managed with rest and pain relief.

Sperm obtained through TESA or micro-TESE are typically very few in number and often immature compared with ejaculated sperm, which means they cannot fertilise an egg on their own. This is why surgically retrieved sperm are always used together with ICSI, in which a single sperm is selected and injected directly into each mature egg — a technique that needs only one viable sperm per egg, making it effective even where retrieval yields only a handful.

There are two ways retrieved sperm can be used. Where the timing allows, the retrieval procedure is scheduled to coincide with the female partner’s egg retrieval, so that sperm can be used fresh for ICSI on the same day — this is generally the more efficient path when it can be coordinated. Alternatively, retrieved sperm can be cryopreserved (frozen) immediately after retrieval and stored for use in a future cycle, which is particularly useful where the two procedures cannot be timed together, where multiple ICSI attempts may be needed from a single retrieval, or where a couple wishes to bank sperm ahead of a treatment that could affect future fertility.

Whether sperm is found at all, and in what quantity, cannot always be predicted with certainty before the procedure, particularly in non-obstructive azoospermia. This uncertainty is discussed openly beforehand, including what the plan would be, and what it would mean, if no sperm were found on the day.