What is sperm DNA fragmentation and how does it affect the chances of conceiving?
There are two types of fragmentation: one that affects only one of the two strands of the DNA helix (single-strand fragmentation) and one that affects both (double-strand fragmentation). Single-strand fragmentation is associated with failed fertilisation, whilst double-strand fragmentation is associated with embryos that develop slowly and may have genetic abnormalities leading to miscarriages. The only technique that examines both types of fragmentation separately is COMET®, which is performed exclusively at the CIMAB® laboratory, a pioneer in the study and treatment of sperm fragmentation.
How can microfluidics help select sperm without fragmentation?
It could be said that microfluidic techniques aim to mimic the selection process that occurs naturally in the fallopian tubes, as it has been proven that the swimming trajectory of sperm is linked to the presence or absence of double-strand fragmentation.
Scientific studies show that the use of these techniques improves fertilisation rates, blastulation (embryos reaching the blastocyst stage) and the percentage of embryonic euploidy (embryos with a normal chromosome count).
What microfluidic techniques are available? What was the Fertile Chip® or Zymot ICSI®?
The Fertile Chip®, which was later renamed Zymot ICSI®, was a filter developed by CIMAB® to select spermatozoa without double-strand breaks. It was a device in which the semen sample was placed in a well, and only sperm without fragmentation were able to pass through a microfluidic channel and reach a second well from which the sperm were extracted for ICSI. For many years, this has been the filter of choice for patients with this condition, and very positive results have been achieved with it. However, the company responsible for its manufacture has recently decided to cease production, so it is currently unavailable. It should not be confused with Zymot Multi®, which is still on the market and available, but is not indicated for double-strand fragmentation.
At the same time, CIMAB® has developed another method of sperm selection using microfluidics that can be replicated in the laboratory. With this method, the microfluidic channels are created on the spot by the embryologists themselves using liquid culture media in specialised plates. The data show very positive results, even surpassing those previously obtained with the Fertile Chip/Zymot ICSI.
Thus, at Love Fertility Clinic we offer this microfluidic sperm selection technique in all IVF treatments, and particularly in cases where double-strand fragmentation has been diagnosed, in order to optimise results and offer the best success rates to our patients.
