29 Aug 2017
Australian study on cow embryos suggests that the photonics technology could improve in vitro fertilization (IVF) outcomes in both animals and humans.
Researchers at Australia’s Centre of Excellence for Nanoscale BioPhotonics (CNBP) say that hyperspectral imaging could improve in vitro fertilization (IVF) success rates, by providing a more objective assessment of the health of early-stage embryos.
Members of the team from the University of Adelaide and Macquarie University have tested the application on cattle embryos, working alongside Sydney biophotonics and informatics company Quantitative, whose engineers have developed a hyperspectral system.
Reporting their findings in the journal Human Reproduction, lead author Mel Sutton-McDowall and colleagues said that the approach had the potential to significantly benefit the IVF industry of the future, improving assisted reproduction outcomes for women.
Sutton-McDowall explains that the hyperspectral approach shows up differences in the metabolism and chemical make-up of embryos before they’ve been implanted, potentially giving clinicians an objective indication of which embryos it would be best to select for the IVF process.
“Pre-implantation screening of embryos generally takes place under a normal optical microscope,” says the University of Adelaide researcher. “Although it’s quite easy to discern poor embryos (due to differences in uniformity), it is far harder for the clinician to determine objectively, the viability of the other embryos.”
Being able to measure embryo metabolism is viewed by many researchers as one of the most important factors determining whether a particular IVF program will be successful. However, Sutton-McDowall says that, at the moment, fertility specialists take a largely subjective approach in deciding which embryos should be used.
“The challenge is how to choose the single healthiest embryo out of this group to maximize the chances of pregnancy,” she said.
In the latest work, differences in metabolic characteristics between embryos exposed to two different oxygen concentrations (20% and 7%) could not be detected with traditional fluorophore and two-channel autofluorescence imaging, whereas the hyperspectral technique was able to spot the difference.
“The benefit of hyperspectral imaging is that it can capture information-rich content of inspected objects. It analyzes every pixel in an image for its light intensity at differing wavelengths,” said Sutton-McDowall.
“This lets us drill down and analyze the hyperspectral signature of each individual embryo, looking for known or anomalous characteristics. It lets us discriminate between embryos, but also measure metabolic differences within individual embryos. We predict that embryos that have cells with homogeneous (uniform) metabolic profiles are the healthier ones.”
Although the approach has only been used on cattle so far, Sutton-McDowall believes there is a great deal of promise for human applications.
“It offers benefits of being a non-invasive imaging approach that provides real-time information to the clinician,” she said.
And while the development of specialized hyperspectral imaging equipment for use in IVF clinics remains several years off, Sutton-McDowall expects to see a surge of interest from those clinics in technologies that are better able to predict embryo development outcomes.
“I think we’ll see this innovative approach commercialized fairly quickly,” she predicted. “IVF is a costly and complex treatment. Any new method that can help improve the odds of women successfully having babies is of benefit to both clinicians and their patients.”
The potential for animal applications should not be underestimated either, with Sutton-McDowall anticipating future commercial opportunities in the livestock and farming sectors.
“Many beef and dairy producers include advanced reproductive technology programs as a regular part of their farming practice,” she said. “Identifying and breeding from elite animals improves herd quality and maximizes productivity.
"If we can enhance the IVF process and improve pregnancy outcomes, farmers will see better animals with healthier genetics and more desirable traits. I see a lot of potential for our imaging technology in this economically important area too.”