Improving IVF Success - Time-lapse photography!
IVF success rates have continued to climb since the first successful IVF live birth in 1978. Significant improvements in success rates have often followed long periods of time during which pregnancy rates have been stagnant. In 2013, the vast majority of patients who have egg retrievals will have some of their eggs fertilize successfully. In spite of the fact that most patients (greater than 90%) will have embryos available for transfer, when considering a group that includes patients of all ages, only 30-40% will achieve a live birth. Understanding why two thirds of patients who receive embryos fail to conceive is the key to further improvements in IVF live birth rates. In recent years we have learned through genetic study of embryos that approximately 50 percent are genetically abnormal and therefore not capable of successful implantation and live birth. Technology, which would differentiate between genetically normal and abnormal embryos, would allow for transfer of only genetically competent embryos with potential to significantly improve live birth rates. Efforts to obtain genetic information about embryos have thus far required embryo biopsy, an invasive procedure. Using this technology (pre-implantation genetic study -PGS) has not resulted in consistently improved live birth rates. Attempts to explain this failure to improve IVF success rates have focused on unknown affects of biopsy on the integrity of the embryo, and variations in the capabilities of genetics laboratories performing these studies.
A non-invasive technology that would enable identification of genetically normal embryos for transfer would have great potential to improve IVF live birth rates. A British group has investigated a novel technique that involves time-lapse photography of embryos during the days of incubation. Cameras mounted within incubators provided time-lapse photographs of each embryo, which could later be carefully studied to identify slow embryo growth, or failure of the embryo to meet important recognized milestones. Altered embryonic growth is highly suggestive of genetic abnormality and in this study allowed for differentiation of genetically normal versus abnormal embryos. Transfer of the “genetically normal” embryos resulted in a 56% greater chance of successful pregnancy. Randomized controlled studies are required to confirm these findings and standardization of the milestones of time lapse evaluation of normal human embryos will need to be carefully delineated in the future so that others may use this technology with comparable results. The effects of repetitive exposure of the embryo to the additional light required for frequent photographs will need to be studied carefully as well before widespread application of this technique can be recommended.
