Tel Aviv University researchers have developed a safe and accurate 3D imaging method to identify sperm cells moving at a high speed. The new technology could provide doctors with the ability to select the highest-quality sperm for injection into an egg during IVF treatment, potentially increasing a woman’s chance of becoming pregnant and giving birth to a healthy baby.
The research, published in Science Advances, was led by Prof. Natan Shaked of the Department of Biomedical Engineering.
The most common type of IVF today is intra-cytoplasmic sperm injection (ICSI), which involves sperm selection by a clinical embryologist and injection into the woman’s egg. “To that end, an effort is made to select the sperm cell that is most likely to create a healthy embryo,” Shaked says.
Under natural fertilization in the woman’s body, the fastest sperm to reach an egg is supposed to bear high-quality genetic material. “But this ‘natural selection’ is not available to the embryologist, who selects a sperm and injects it into the egg,” Shaked says. “Sperm cells not only move fast, they are also mostly transparent under regular light microscopy, and cell staining is not allowed in human IVF. We sought to develop an entirely new type of imaging technology that would provide as much information as possible about individual sperm cells, does not require cell staining to enhance contrast, and has the potential for enabling the selection of optimal sperm in fertilization treatments.”
The researchers chose light computed tomography (CT) technology for the unique task of sperm cell imaging. Using this technique, the researchers obtained a clear and accurate CT image of the sperm at very high resolution in four dimensions: three dimensions in the space at resolution of less than half a micron (one micron equals one millionth of a meter) and the exact time (motion) dimension of the second sub-millisecond.
“Our new development provides a comprehensive solution to many known problems of sperm imaging,” Prof. Shaked says.