125 Toward a new recategorization for pathogen risk transmission via in vivo-derived and in vitro-produced embryos: an international survey to facilitate the recategorization mission

One of the Health and Safety Advisory Committee (HASAC) projects underway is the recategorization of risk of transmission of pathogens via in vivo-derived (IVD) and in vitro-produced (IVP) embryos. To replace the current International Embryo Technology Society (IETS) categorization system, which covers only IVD embryos and is unsuitable for IVP embryos, the IETS is moving toward a new categorization system that covers both IVD and IVP embryos. The new system provides for three categories of risk instead of four categories: Category 1 (negligible risk of transmission), Category 2 (unknown risk of transmission), and Category 3 (non-negligible risk of transmission). The list of pathogens for each category will be published in the IETS Manual 5th edition. At the last HASAC meeting held in Denver, Colorado, USA in January 2024, members of the research subcommittee concluded that the majority of pathogens, especially for IVP embryos, belong to category 2 because of a lack of studies. As there is a long list of pathogens to review, the research subcommittee decided to focus only on pathogens of interest in the international embryo trade. The purpose of the survey sent to embryo transfer practitioners and embryologists was to help the IETS identify the pathogens that were assessed to be important to international trade. We obtained 23 responses from practitioners, predominantly from the United States (56.5%), with additional responses from Finland, United Kingdom, France, Romania, Australia, Japan, and South Africa. This geographic skew suggests that the resulting data may reflect Western, particularly US, regulatory perspectives. Notably, there were no responses from South America and minimal representation from Asia and Africa. The respondents, who primarily work with bovine embryos, provided a ranked list of diseases for both types of embryo transfers and also for sperm (Table 1). This list will guide further research and categorization efforts, enhancing the understanding of pathogen risks and informing future regulations.