ICSI - Intracytoplasmic sperm injection

ICSI – the modern method of artificial insemination

ICSI (intracytoplasmic sperm injection) is the most common method of artificial insemination in IVF treatment. In this method, a single sperm is injected directly into the egg using a fine pipette.

How is IVF different from IVF/ICSI?

In general, two main methods of artificial insemination are used: conventional IVF and ICSI as an additional measure within the IVF treatment. In classical IVF (without ICSI), sperm are placed in the test tube with the eggs. The sperm must meet the egg and penetrate it thanks to enzymes. The fertilization of the egg is successful as soon as a sperm succeeds in penetrating the cytoplasm of the egg nucleus. Nowadays, the ICSI method is most commonly used in laboratory practice. In this method, the egg can be fertilized with sperm of lower quality (e.g. reduced motility, unusually shaped sperm, inability of the sperm to attach to and penetrate the egg). Another reason for ICSI fertilization is low sperm and poor egg quality.

In modern clinics, the ICSI method is used most often. It is considered the method of first choice, fertilization by the classical IVF method is approached only in exceptional cases. Classical IVF has a significantly higher risk that the eggs will not be fertilized.

How does ICSI work?

Selecting the appropriate sperm is the task of the embryologist. He selects the specific sperm under a microscope with high magnification. Many methods for determining sperm quality, such as ZymotChip or MACS, can help with the selection. The selected sperm is injected directly into the inside of the cell with the help of a fine pipette, at this moment, fertilization takes place. The fertilized egg is placed in an incubator, where it grows to the blastocyst stage after 5 to 6 days. Samples are taken from it and sent for genetic diagnostics. The embryo is frozen and transferred to the uterus in the next cycle.

When is ICSI used?

The ICSI method is suitable for all treated couples and is used in the following cases:

• Poor spermiogram – a proven low sperm count, unusually shaped sperm, as well as their reduced motility.
• When using sperm obtained by TESE or MESA (surgical procedure).
• When using the cryopreserved sperm.
• If not many eggs were obtained.
• If donor oocytes are used.
• If previous IVF cycles have failed.
• If preimplantation genetic diagnosis is to be performed.