es of fertilization have failed in the past, or when the man has an extremely low sperm count or motility. Smith does not think the use of microfluidics will replace ICSI, but he says it could offer another option to many couples whose situations do not require ICSI, a process that can cost an extra $1,500 to $2,500 in addition to standard IVF costs.
"While ICSI bypasses all natural selection, the use of microfluidic channels more closely resembles in vivo insemination. The microfluidic environment also may possess conditions more suitable for efficient sperm-oocyte interaction than the culture dish," he says.
During the early stages of the study, researchers found that, contrary to their initial hypothesis, a much lower fertilization rate was achieved with the microfluidic device (12 percent) than in culture dishes (43 percent). They then hypothesized that as sperm concentration is decreased, fertilization rates would improve in microchannels. At these lower concentrations, the combined fertilization rate was significantly higher in microchannels (27 percent) than in culture dishes (10 percent).
The authors note that the research has only been conducted on mice, and that more testing and possibly the development of auxiliary technology will be needed before IVF by microfluidics is a viable option for humans.
Still, the research is very promising, says lead author Ronald S. Suh, M.D., now with Urology of Indiana LLC in Indianapolis who was a resident in the U-M Department of Urology when he wrote the paper.
"There has been a large amount of research on almost every aspect of IVF. The exciting thing we're seeing here is going the potential of integration of all of these things. In the future, you will be able to take patients with low sperm counts, use microfluidics to select the best sperm, and achieve fertilization in one step," he says. "That integration is really what is going to make microfluidics change IVF."
In addition to Smith and Suh, other authors of the paper are Dana A. Ohl, M.D., professor of urology