When men don't have any sperm in their ejaculate and they're trying for a baby with their partner, doctors try and extract the swimmers directly from their testicles instead. Success rates of the process are strangely low — but a new way of tracking sperm could help improve things.
Usually, doctors blindly guess at where in the testes to take a sample from — but sperm aren't evenly spread throughout the area and there often aren't many to be found. That means that the process only provides viable sperm to use in IVF around 50 per cent of the time. Up until now, there's been no reliable way of tracking the sperm during the procedure, but a team of researchers from the University of Munich reckons that probe-based confocal laser endomicroscopy could do the trick. The technique is a relation to conventional optical confocal microscopy, which uses two light detectors rather than one to sharpen images and even render them in 3D. The use of laser light — said to be safe within the human body by the researchers — allows them to see within structures where normal visible light wouldn't and tag the sperm with contrast agents to help them show up better.
In tests on excised human tissue, acquired from the testes of transsexual patients after surgical removal, the team found the technique was able to reliably identify single spermatozoa in the tubules of the testes, even tracking their motion. These samples were crucially low in sperm — like many of the men who will need the technique during sperm extraction — because the patients had been taking long-term medication to suppress their creation. The researchers hope that the technique could be used in the near future to help doctors identify and harvest sperm for use in IVF. [BioPhotonics via MaterialsViews]