PICSI: Only mature sperm can fertilise an egg

Hyaluronan indicates quality sperm

The PICSI method is based on the ability of quality sperm, capable of fertilisation, to bind to hyaluronan, which is placed in a culture dish. Bonded sperm are then used for ICSI. The selection of quality sperm is vital for better embryo development. Clinical studies show that the PICSI method demonstrates the best results in terms of the number of blastocysts compared with ICSI and the classic (conventional) IVF cycle. The use of hyaluronan also increases the number of early embryos with 2 primary nuclei, which is a necessary process for egg fertilisation.

Using this method, the embryologist can be certain the sperm has completed its development and can recognise and bind to hyaluronan. This process has a positive effect on the later formation of the blastocyst. In the past, it was found that sperm affects embryogenesis in two phases. Therefore, in the first early phase, poor sperm selection can affect fertilisation, the fusion of germ cells (i.e. the egg and sperm). In the second phase, sperm also affects the genetic material of the embryo. If the genetic material in the sperm is damaged and subject to fragmentation, this can lead to a reduction in the number of cultured blastocysts, a reduced level of implantation, or to miscarriage. Hence embryos after PICSI show fewer chromosomal abnormalities (Casillas et al.).

In general, cycles using PICSI demonstrate a higher number of pregnant patients and lower chance of miscarriage.