What are the sperm preparation techniques for IVF?
The basic processing of sperm is mainly about the separation of sperm from seminal plasma and at the same time, if possible, about the separation of as many immobile sperm as possible.
Basic processing methods include, for example, swimm-up (the oldest method, which is no longer widely used today – based on active sperm movement), gradient sperm separation (used in Sanatorium Helios) or microfluidic sperm separation (MFSS).
In general, these methods select well-motile sperm, which are more likely to be functional and genetically sound (but this is not necessarily the rule).
How is the technique of processing sperm and fertilizing eggs decided?
We know from our long-term results that sperm with fragmented DNA occur almost as often in men with normal semen analysis values as in those with pathological values of a semen analysis. In addition to the basic semen analysis, it is equally important to examine the integrity of sperm DNA and, based on the overall results, decide on a specific method of fertilization (classical fertilization “in a test tube”, ICSI, PICSI).
The actual fertilization of the egg may be preceded by another selection of sperm – MACS (magnetic sorting of sperm according to their actual viability) and / or PICSI (selection of well-mature sperm with the ability to bind to the egg). In indicated cases we combine MACS and PICSI techniques.
What is MACS?
MACS (magnetically activated cell sorting) is a non-invasive technique of selecting sperm based on their functional state. Allows you to adjust a sperm sample to increase the chances of successful fertilization with any assisted reproduction method. In MACS, sperm with damaged DNA are captured and removed. Sperm that pass this selection have better properties than the original sample.
Damaged sperm with excessively fragmented DNA naturally initiate the process of cell death. In the early stages of cell death, which may not otherwise be recognizable, cells expose on their surface a substance phosphatidylserine, which is normally only inside the cell. The MACS system contains magnetic nanoparticles that bind to this substance. Using a magnetic field, it is possible to capture such sperm and remove them from the sample. They can then be used for any method of assisted reproduction. The chances of fertilization with these sperm are higher.