Gonadotropins, including human chorionic gonadotropin (hCG), have been used since and for several decades to treat infertility by ovarian stimulation. hCG is the most important protein for embryogenesis and embryo development and implantation in uterus upon fertilization of oocytes. The hCG used for in-vitro fertilization (IVF) is being extracted from urine of pregnant women, and it does inevitably contains other proteins secreted into urine. The presence of other proteins varies from batch to batch, and it can be significantly high. Due to the fact that many of the proteins identified in these formulations can trigger an allergic reaction, which, in turn, can affect the embryogenesis and prevent embryo implantation, it is very important to check the amount and type of contaminant proteins in pharmaceutical formulations. It was found that the total protein content varied from batch to batch, and a large number of contaminant urinary proteins were identified in all analyzed samples except for the recombinant product.
Part of the book: Embryology
New technical and methodical and more efficient approaches beyond preimplantation genetic screening (PGS) are needed to elevate success rates in in vitro fertilization (IVF). One new approach could be the characterization of the embryos’ proteome during the IVF process. This means that specific proteins secreted by the embryo in the surrounding cultivating medium can be analyzed and compared between embryos in order to identify potential markers for a successful embryo transfer and resulting pregnancy. Furthermore, this procedure could result with understanding the processes during the whole time of incubation, from the moment of oocyte fertilization until embryo transfer and subsequently implantation by analyzing the culturing medium used in multiple culture medium exchange during the cultivation period. This procedure of embryo transfer to a new culture medium is essential for the embryo’s development and is performed daily or at least when the embryos reached the stage of embryoblast at day 4. The remaining medium after embryo removal is routinely discarded. However, this medium still can be useful for a detailed analysis of proteins and lipids that were secreted by the embryo during the previous incubation process and could help gaining information on the embryos’ current developmental status.
Part of the book: Innovations In Assisted Reproduction Technology