A comparison of the in vivo and in vitro environment of the human preimplantation embryo

The culture environment of the human preimplantation embryo not only affects the effectiveness of IVF treatments, but also the health of the children born from such treatments. In this thesis, we describe our studies towards improving the effectiveness and safety of IVF by evaluating the in vitro and in vivo environment of the human preimplantation embryo.
We first performed an observational study to determine the pH-stability and pH differences between (different) batches of culture media of human embryo culture media during culture and during storage. We continued to determine the biochemical composition of fifteen commercially available human preimplantation embryo culture media. We then shifted our focus towards the natural, in vivo environment of the human embryo in the human uterus. More precisely, we measured the composition, temperature and pH of human uterine fluid at the time when the uterus is receptive for implantation. Finally, we compare our in vivo findings to the current in vitro culture conditions used in IVF laboratories worldwide.
Our findings provide novel insights in the in vivo environment of the human preimplantation embryo. In addition, our findings set the path towards optimizing the currently used human embryo culture system so that it more represents the conditions in the human uterus at the time of the menstrual cycle when an embryo would normally reside there. Further research should be conducted to study the clinical effects of such a novel embryo culture system, focussing on its effectiveness and safety.