Expected Contributions of TLM Technology in the Future of Mammalian Embryology
It is obvious that being able to summarize and cite all published articles in TLM field is beyond the scope of this manuscript. Here, we have therefore aimed at focusing on important aspects of the technology and their impact on mammalian and human embryology as well as assisted reproductive technologies. Today, numerous different TLM systems have been continuously developed, improved, validated, and are available in the public and research hospitals, clinics as well as private IVF Centers. The authors of this manuscript have no doubt that incubators with the ability of TLM analysis will soon replace conventional standard cell culture incubators in both research centers as well as clinical embryology laboratories. The rate of change, on the other hand, will depend on the relative and competitive pricing policies of the producers as well as technological investment plans of institutions.
TLM analysis systems have already changed our classical twodimensional embryo follow-up and analysis protocols into a fourdimensional (or even six-dimensional) world, where every single developmental event or sequence of events could easily be observed, recorded, and evaluated in detail, or can even be integrated and used to correlate/compare with a gradient of multiple variables. In this way, we can collect tons of new information such as developmental modifiers, growth factors, their molecular-level interactions and possible effects on implantation, peri-implantation, prenatal development, and live birth. Thanks to such systems, epigenetic changes/defects or variations during mammalian preimplantation development will also continue to be evaluated and translated into human embryology and ART. We can therefore predict that, in the near future, we will eventually be analyzing possible effects or projections of unique TLM parameters on the fetal development and will be using them to select/de-select the embryos for embryo transfers in ART programs.
Besides its advantages on improving the embryo culture conditions and selection for the implantation-competent embryos, TLM technology is raising the bar upwards on the standardization of these advantages by minimizing the inter-observer evaluation differences and by creating unique algorithms which allow the automotized selection of the most competent embryos for implantation. Such advantages can surely have huge potential to change our view of mammalian and human embryology and clinical treatment protocols completely. As an example, although blastocyst culture and transfer is known to be the most advanced and successful protocol for human ART, it can come with a high price of loss in embryo viability due to culture conditions. Having predictive software which is based on early embryo developmental dynamics can therefore make blastocyst culture obsolete and save millions of couple from every negative aspect (financial, psychological etc.) of ART failures and cancellations.
Implementation of TLM technologies in modern mammalian embryology can be considered as the end of classical approach and the beginning of a new era in the field of mammalian embryology. Our expectations from this technology is on the other hand completely depends on the improvements in embryo culture conditions and the media. Just like most of our knowledge accumulated after a suitable culture media has been produced in the 1950s, our understanding and imitation power for the nature in four dimensions require properly designed embryo culture systems that uninterruptedly and dynamically hold and support them for 5-6 days. Without such improvements, the implementation and the possible positive benefits of TLM in the laboratory can hardly be measured in the current clinical conditions with a variety of modular (distractive and invasive) clinical programs and protocols (freezing on different stages, embryo biopsy, etc.).