A new means of analysing sperm developed by researchers at the University of Birmingham could bring substantial improvements to male fertility testing.
The new technique uses imaging software called Flagellar Capture and Sperm Tracking (FAST) to track the speed and action of the sperm flagellum, or tail. This provides vital information about whether the sperm in an ejaculate sample would have been able to reach and fertilise an egg, providing a more sophisticated understanding of male fertility than traditional means.
The project was developed by the University of Birmingham’s School of Mathematics in partnership with the university’s Centre for Human Reproductive Science. The results have been published in the journal Human Reproduction.
Current methods of sperm analysis have been restricted to counting the number of sperm produced in a sample or tracking the head of the sperm cells to note their movements. However, these tests have their limitations. While sperm count and motility can adequately predict how long conception may take, it does not directly measure the fertilising potential of the sample.
FAST enables the researchers to measure the miniscule forces exerted on and by the flagellum through a combination of rapid, high-throughput digital imaging, mathematics and fluid dynamics.
The team hopes this will enable clinical researchers to better understand how sperm motility relates to fertility, and develop new interventions to tackle male fertility problems.
University of Birmingham Centre for Human Reproductive science professor Jackson Kirkman-Brown said: “Diagnostic techniques are crude and there are still no drugs available for treating male infertility. We know that sperm motility is a major factor and so being able to analyse the movement of the sperm in detail will ultimately help us to identify appropriate treatments or lifestyle changes to tackle male fertility problems, giving couples clearer answers and enabling better decisions.”
The better diagnoses that the team behind FAST hopes to enable mean that infertile couples can also be assigned more appropriate fertility treatments.
These includes fertility pathways such as intrauterine insemination (IUI) to inject sperm directly into the womb; in-vitro fertilisation (IVF), where an egg is manually fertilised in a sperm culture laboratory dish then returned to the womb; or intra-cytoplasmic sperm injection (ICSI), where a single sperm is injected into an egg through a fine glass needle.
University of Birmingham mathematics professor Dave Smith, who led the study, said: “The tools available to understand sperm – manual counting with a microscope – have not changed much since the 1950s. However, think of the amount of technology – camera, computing, connectivity – that we all now have access to. This project is about harnessing these 21st century technologies to address male fertility problems.”