An innovative new sperm sorting procedure offers the possibility of improved success rates for in vitro fertilization (IVF).
IVF is a costly procedure without guaranteed success. Women under 35 have only a 21.5 percent chance of a full-term live birth from a single round of IVF. At an average of $10,000-$15,000 per round in the U.S., improving the odds of IVF success is vital for the financial and emotional well-being of those who experience fertility problems.
Fundamentally, IVF relies upon placing healthy sperm in the vicinity of an egg to maximize the chances of a sperm penetrating the egg. To do this, sperm are sorted into those that can swim well (“swimmers”) and those that can’t (“non-swimmers”). Only swimmers are used to fertilize eggs.
The process of sorting sperm, however, can damage the DNA within them. This is because sperm are sorted through centrifugation (a sort of spinning), whose strong shearing forces can tear at the DNA strands within sperm nuclei.
A new technique under development by Dr. Afrouz Ataei of Florida Atlantic University offers a promising new means for sorting sperm that avoids the damaging centrifugation step.
Dr. Ataei has developed a microchip, in which sperm swim against a current. As Dr. Altaei explains, her chip exploits sperm’s natural tendency to turn towards an applied current and then swim against it.
Prior to running sperm through the chip, they are analysed for things like concentration, count and most importantly, a velocity parameter. The velocity parameter is a measure of the sample’s ability to swim against a flow and this determines the actual flow rate used during the process. In this way, each run through the system is tailored to its specific sperm sample.
The sperm samples that they have been able to collect, says Altaei, come close to 100% motility.
Still in early stages of development, Dr. Altaei and her colleagues are continuing to optimize their chip, hoping to increase the concentration of sperm collected before filing a patent on their design.