Intracytoplasmic injection or ICSI is one of the techniques that in vitro fertilization treatment uses to increase fertilization rates in this treatment. It is generally used when infertility is related to the malefactor, such as little presence or defects in the sperm. In an IVF traditional, both gametes are placed together so that over time they can be fertilized so that this is possible and at least one of the sperm can penetrate the zona pellucida of the ovum, it must be in optimal conditions of mobility, quantity, and form, with ICSI the male sperm that is considered most viable for fertilization is chosen.

The sperm with the best mobility and morphology is selected, to be placed inside a tiny pipette to inject it directly into the oocyte, depending on the ovules of good quality.