Scientists in the United States have created obstacle courses to help sort the fastest and best-formed sperm for use in IVF procedures. The obstacle course is called SPARTAN (or the Simple Periodic ARray for Trapping And isolatioN) and is 14mm long – sperm have to swim through three-dimensional pillars to emerge at the other end. Any sperm that make it within a specified time frame are judged to be the best candidates for IVF.
Professor Erkan Tuzel states that, “with SPARTAN, we not only get sperm with excellent motility, but also with normal morphology and better DNA integrity, helping families worldwide by reducing the stress of multiple IVF procedures, while potentially increasing pregnancy rates.” Only normal sperm should make it to the end of the obstacle course – sperm with bent necks will swim in circles without progressing through the full course, while sperm with large heads also struggle to get through.
Theoretically, self-sorting sperm without the need for pumps and chemoattractants means that andrologists and embryologists would not need to use centrifugation or washing after the sperm has been sorted, making this a relatively cheap, one-step process to retrieve the highest quality sperm from a sample. It is said that SPARTAN also improves on previous processes by cutting the amount of time it takes by up to 88% – it takes just 10 minutes to sort sperm using this technique, whereas conventional procedures take anything from 30 to 90 minutes. If independent studies show that the claims made for SPARTAN are valid, it will no doubt be adopted throughout the world but until that time, most scientists will stick with tried and trusted methods.
Sperm morphology is believed to have a relationship with fertility potential, so it is important to use the best sperm from a sample to maximise the changes of success with every treatment. A “normal” sperm sample, i.e. one which should not result in reduced fertility, may have up to 96% of sperms morphologically abnormal.
All new techniques may introduce new problems of their own. One of the limitations of most sperm-sorting devices is that they can only be used for ICSI procedures, which only require a single sperm per egg, rather than conventional IVF or IUI which require larger numbers of sperm. Here at Concept, we feel that adding ICSI to IVF is an additional procedure which should be avoided wherever possible, in order to obtain the best pregnancy results.