A new technique that takes 3D film of moving sperm could help doctors select those sperm that have the best chance of fertilizing an egg and leading to a successful pregnancy in cases where couples are undergoing in vitro fertilization (IVF) fertility treatments. More from The Optical Society, the professional scientific organization that published the research in its journal:
Now doctors may soon have a new technique to help them sort the good sperm cells from the less viable ones: a tracking system, developed by a team of researchers from four European institutions, that takes 3-D movies of living sperm. In addition to showing the sperm's movement and behavior in real time, the novel method simultaneously provides detailed 3-D imaging of the sperm's form and structure to detect potential infertility-causing anomalies, such as the "bent tail" that prevents the cells from swimming straight.
The researchers say this is the first technique for collecting data on sperm cell motility—a key predictor of IVF success—in three dimensions and over time. They describe their method in a paper published today in The Optical Society's (OSA) open-access journal Biomedical Optics Express.
Currently, sperm concentration and mobility in semen are assessed either by subjective visual evaluation or a process known as computer-assisted sperm analysis (CASA). While the latter provides more detail and fewer errors than the former, CASA still only allows tracking and imaging in two dimensions. In their new technique, the team of researchers from Italy and Belgium combined microscopy and holography—the creation of 3-D images—to visualize live sperm in not only two dimensions (the x and y positions) but according to their depth (z position) as well.
And, "by acquiring a video of the moving sperm in 3-D, we add a fourth dimension – time," said lead author Giuseppe Di Caprio of the Institute for Microelectronics and Microsystems of the National Research Council (NRC) in Naples, Italy, and Harvard University in Cambridge, Mass.