In Vivo implantation Murine Modeling

Ethical and legal restrictions limit human implantation knowledge. Alternative tools, such as retrospective clinical studies, in vitro three dimensional cell culture modelling, and in vivo implantation animal modelling provide some insight. While in vivo implantation murine models have proven useful, none are recognised as standard. Therefore, the overall research objective was to gain an understanding of improved standardization of in vivo implantation murine models, suitable to explore implantation and preliminary studies surrounding In Vitro Fertilization (IVF) intervention potential. A selection of models, termed optimal or suboptimal by their level of implantation, were examined and compared to natural mouse pregnancy. Embryo transfer (ET) outcomes on day 17 post coitus (pc) and the ability of the most suitable optimal and suboptimal models to detect consequences of manipulated embryos, an IVF intervention, were explored. Significant inconsistencies within suboptimal models led to investigating the beginning of endometrial receptivity within natural pregnancy, and synchronous and asynchronous uterine ET. Assessed time points were set to capture the pre receptive and receptive endometrial phases. Examining at least three mice per time point, achieving 80% statistical power, ensured statistical robustness. This research extended current knowledge in three ways. Firstly, ETs performed at two hourly intervals, demonstrated significant influence of the distinct moments of coitus, ET and autopsy on implantation rate consistency. Previous research, which specified the day of transfer rather than hours pc, was unable to reveal such influence. Finer control of coitus, ET and autopsy demonstrated improved implantation rate consistency, necessary for model standardization. Implementation within wider research could improve statistical robustness and facilitate greater comparison between research groups. Secondly, assessed time points extended beyond previous the literature, which did not report endometrial receptivity ...