New Technologies to Improve Embryo Assessment

Abstract

Embryo quality is a key factor in determining whether an IVF cycle will result in a live birth. Current approaches for assessing embryo quality are subjective (morphology) or invasive (biopsy) and are not always predictive of live birth. Development of an accurate and non-invasive method to assess embryo quality would likely improve IVF success. We have taken a different approach towards developing a non-invasive diagnostic for embryo quality: optical imaging. We use low levels of light to illuminate the embryo and obtain spatial information on cell metabolism as well as biophysical properties of the embryo. Here I will present our work showing that hyperspectral imaging – captures natural autofluorescence emitted by the embryo – can be used to accurately discriminate between euploid and aneuploid mouse blastocysts (inner cell mass). Importantly, we show that this form of imaging is safe: compared to embryos that were not imaged, hyperspectral imaged embryos had similar, and not significantly different, pregnancy and implantation rates, with offspring weight at weaning also comparable. Another potential optical approach to assess embryo quality is digital holographic imaging. To date, little attention has been paid to the physical parameters of an embryo and whether these could be markers of embryo quality. One such physical parameter is refractive index. We have shown that digital holographic microscopy is able to measure very small changes in refractive index between good and poor-quality mouse embryos. Importantly, these optical approaches occur in the absence of stains or exogenous tags. Used alone, or in combination, such optical approaches may prove beneficial in developing to an accurate, non-invasive diagnostic for embryo quality.