For couples dealing with severe male-factor infertility-especially when the semen sample shows zero sperm, also known as azoospermia-the journey to parenthood may be truly overwhelming. These days, reproductive medicine offers novel opportunities through surgical sperm retrievals: PESA, TESA, and M-TESE, all of which, combined with ICSI, can make biological parenthood possible even in the most challenging of cases.
This blog describes how these procedures work, why they’re used, and what the latest success rates show.
Understanding how surgical sperm retrieval helps in ICSI
Sometimes men produce normal amounts of sperm, but a blockage in the reproductive tract prevents delivery of the sperm into the semen. In other cases, a man may produce extremely low numbers of sperm within the testis, not enough to appear in the semen. In these cases, physicians can bypass the normal delivery process by directly retrieving sperm from the testes or epididymis through minimally invasive or microsurgical techniques.
Once retrieved, even if the sperm count is extremely low or the sperm appear immature, ICSI allows the embryologist to inject one healthy sperm directly into an egg. This eliminates the need for the sperm to swim or penetrate the egg on its own. Because only one sperm is required per egg, even men with almost no natural sperm output still have a realistic chance of fathering a child.
PESA, TESA, M-TESE — What’s the Difference?
PESA is a procedure indicated in cases of obstructive azoospermia, where sperm production is normal but the sperm cannot come out because of a blockage. A fine needle is inserted into the epididymis and sperm is aspirated gently. The procedure is simple and quick, often without anesthesia. Because the production of sperm itself is normal, the quality of the retrieved sperm is usually good; this explains why PESA-ICSI cycles show very encouraging results.
TESA, or testicular sperm aspiration, involves the direct aspiration of sperm from the testes using a fine needle. TESA is indicated for individuals with low or inconsistent sperm production or whenever PESA fails in retrieving enough sperm. Sperm aspirated through TESA may be less mature or of lower motility, but with ICSI, embryologists can still choose the best-appearing sperm for fertilization.
M-TESE is the most advanced technique, performed using a high-powered surgical microscope. This allows the surgeon to carefully identify even the smallest areas of active sperm production in the testes. In men with severe non-obstructive azoospermia, where natural sperm production is extremely limited, M-TESE is usually the best hope of retrieving sperm.
Success Chances When Using Surgically Retrieved Sperm
In the case of obstructive azoospermia, the sperm retrieval rate with PESA is very high, nearly 90-100%. Since sperm formation is normal, the ICSI outcome using PESA-retrieved sperm generally shows fertilization rates between 65-80% and pregnancy rates ranging from 45-55% per cycle. It has emerged as one of the most reliable combinations in male infertility treatment.
TESA shows slightly lower success, as the sperm retrieved directly from the testis can be immature or structurally weaker. TESA retrieves sperm successfully in 40-60% of cases. Fertilization rates with TESA-ICSI are generally 50-70%, and pregnancy rates are at about 30-45% per cycle, depending on the woman’s egg quality and the lab conditions.
Although more intricate, M-TESE represents the most effective approach in cases of severe non-obstructive azoospermia. Because the surgeon is better able to locate the healthiest sperm-producing tissue, retrieval success by M-TESE in even the most difficult cases can approximate 50-70%. ICSI performed with M-TESE sperm demonstrates fertilization rates of approximately 60-75%, with pregnancy rates ranging between 35-55%, thus representing the best option for very low sperm-producing patients.
What Really Determines the Ultimate Result?
As powerful a tool as surgical sperm retrieval has become, the final success with ICSI depends on several factors. The most important among them is the female partner’s egg quality, which declines naturally with age. The healthiest sperm in the world cannot compensate for significantly poor egg quality. Another determinant of outcomes is the underlying reason for the man’s azoospermia. In general, men with obstructive azoospermia have better success compared with men whose testes make sperm in very small or scattered amounts.
Surgically retrieved sperm may sometimes carry higher DNA fragmentation or be less mature, particularly in nonobstructive azoospermia. Advanced techniques of sperm selection include MACS, microfluidics, and hyaluronan-based selection (PICSI) that help the embryologist to select the healthiest sperm for ICSI. The expertise of the embryology team along with the technology at the IVF lab significantly influences fertilization and embryo development.
Conclusion
ICSI in combination with surgical sperm retrieval has transformed fertility treatment for couples suffering from severe male factor infertility. Whether the sperm is retrieved using PESA, TESA, or M-TESE, even a minimal amount of viable sperm can suffice to achieve a successful pregnancy. PESA provides good results in obstructive cases, TESA is one of the reliable options for low sperm production, and M-TESE provides hope for the most difficult nonobstructive azoospermia patients. With the use of modern microsurgical techniques and advanced embryology, even those men who at one time had no sperm in their semen now have the possibility of biological parenthood. Provided the ovarian health of the female partner remains favorable and the IVF lab is adequately equipped, the chances of success remain promising and continue to improve with ongoing medical advancements.