ICSI (intracytoplasmic sperm injection) is a procedure carried out in an embryology laboratory. This technique is applied in approximately 95% of IVF cases. It consists in injecting a single sperm directly into an egg with a very fine glass needle (micropipette). This technique is applied effectively in the case of male infertility: both in the case of the low count of normal sperm cells in ejaculate and in the case of sperm collection during testicular or epididymal aspiration. In any other case, it also increases the rate of achieved fertilizations, therefore it is the globally preferred method of egg fertilization.
Based on the generally accepted medical and scientific standards, in order to increase the chance of fertilization, sperm cells with the best morphology are selected. However, this does not give any certainty that the result of treatment will be positive. Following the introduction of a single sperm to an egg cell, the natural process of conception begins.
The ICSI technique has been used since 1992. In accordance with current knowledge, this process does not cause changes in the genetic material; nevertheless, the long-term consequences of the ICSI technique for children already born are difficult to determine definitively. The opinion that the fertilization using the ICSI technique may be the cause of the increased rate of fetal defects or retarded intellectual or motor development has not been proved.