Intracitoplasmatic Sperm Injection
It consists of the Introduction/Injection of a single spermatozoon within the oocyte. We only need one single living spermatozoon for each oocyte, therefore, unlike IVF, it can be carried out with low quality semen specimens, even in cases of total absence of spermatozoa in the ejaculated, since these are obtained by a small operation practiced on the man, called testicular biopsy, which can be carried out once the oocytes have been obtained. However, for the first time in the world we have developed techniques that allow using spermatozoa from any precedence (ejaculated, epididimus or testicle) successfully for ICSI after their unfreezing process. Furthermore, in most cases it is not necessary to unfreeze the whole frozen specimen, therefore one single biopsy may allow several ICSI attempts.
Success possibilities for ICSI are similar to conventional IVF. However, it is important to make clear that couples submitted to ICSI started from a rather more severe primary problem: the difficulty to fertilize with male sperm. So it is important to remark the fact that, through this technique, even with the worst quality semen specimens, only in the 2% of cases there is a failure in fertilizing all the injected oocytes, but they are usually cases with less than three mature oocytes available.
When the semen specimens are very pathological, we always make complimentary analysis to detect whether there are chromosomal and/or genetic defects which may justify the pathology or even to recommend that specimen not to be used without the appropriate precautions. In these cases, it is also more probable to obtain worse quality embryos.