The developmental potential of an individual embryo after fertilisation and the endometrial receptivity are critical for the success of medically-assisted reproduction (MAR), albeit difficult to evaluate. To assess endometrial receptivity, mainly hysteroscopy and a few molecular diagnostics with rather weak utility are currently available. Understanding how normal endometrium is regulated to interact with the blastocyst is essential to define molecular mechanisms altered in suboptimal endometrium. Research area D aims to utilise in vivo-inspired models (resulting from data generated by single cell sequencing, 3D high resolution microscopy, and microRNAs) to optimise MAR and to study molecular mechanisms of endometrial receptivity.