Environmental pollution produces a wide range of negative effects on human health, including different reproductive problems. As far as assisted reproduction is concerned, there are still many gaps in the interactions that the compounds may have with different types of cells, gametes and embryos, which are manipulated daily through different techniques within the in vitro fertilization laboratories (IVF). Likewise, the air quality of these laboratories depends on the people, activities and elements present inside and outside the laboratory, for which there is a constant risk of contamination that can cause short and long term embryo development failures. Thanks to the empirical experience, studies in animal models and retrospective studies, it has been possible to identify and describe some of the pollutants present in the IVF laboratory and also, to propose mechanisms to counteract the effects they produce on the embryo development and clinical outcomes (rates of implantation, pregnancy and birth, among others), mainly through the development of filtration systems that can be very efficient. However, many of the studies also emphasize on how difficult it is to eliminate certain contaminants, since some of them are produced within the same IVF laboratory. Despite the known information available, further prospective studies are needed in order to evaluate specific interactions between compounds and human gametes or embryos such as induction of oxidative stress, negative effects on membranes and organelles, as well as deleterious effects on DNA, among others. During the development of this thesis, a test plan has been carried out focused on determining the specific effects of two of the most frequently encountered volatile organic compounds (VOCs) within the IVF laboratory. The study complied three parts: the first focused on analyzing the air quality characterizations of the IVI clinics, to assess which compounds were most frequently found within the IVF laboratory. The second part focused on a comparative study of the developmental rates of embryos of a control group and embryos exposed to one of the two contaminants (Benzene and Limonene), also evaluating the rate of expansion and the morphology of the groups. Finally, in the third part of the study, the karyotype and the mitochondrial DNA content of the embryos were determined. The results allowed to determine that, the presence of benzene and limonene directly diluted in the embryonic culture medium can produce deleterious effects on the development of the embryos, possibly by mechanisms related to its metabolism and by oxidative stress, which can also influence the chromosomes errors, found mainly after exposure to benzene. These results are of particular interest since, to date, this is the only study that addresses through morphological and chromosomal parameters, the implications of the presence of volatile organic compounds in the environmental air of human embryos.
2017-09-27
