In many cases, there are too few sperm cells available which are motile and of normal morphology. In such cases, it is likely that no egg cell can be fertilized when the sperm cells are added.
For such cases, the intercytoplasmic sperm infection (ICSI) technique is recommended. This means that even with a poor sperm test result fertilization can be achieved. The minimum requirement is one motile sperm cell per egg cell.
IMPORTANT: even if the ICSI technique is used, fertilization can fail to take place or only a few of the egg cells can be fertilized. As with traditional IVF (in-vitro fertilization) this can be due to the egg cells or the sperm cells. Unfortunately, we mostly cannot give an exact reason as this is not possible with today’s methods.