Testicular sperm extraction (T.E.S.E) is recommended for patients with a blockage in the epididymis, very close to the testes (from previous surgery, infection or a genetic birth defect) or blockage in the ejaculatory duct.
It is also recommended for men with extremely poor sperm production, that there are not enough spermatozoa to reach the end of the reproductive tract. Currently, achieving a pregnancy in cases of severe male factor infertility has become a routine. However, there is still concern about using testicular sperm since, in most cases, the etiology behind poor sperm production remains unknown.
Therefore, application of ICSI in couples with severe male factor infertility can result in offspring with an enhanced risk of inheriting genetic abnormalities.
However, the use of immature germ cells in clinical practice has raised many concerns. It is therefore crucial to investigate the genetic stability of these cells on animal models.