Models for the study of uterine receptivity for blastocyst implantation

A variety of models have been developed to study endometrial receptivity wh ich involves normal, appropriately timed endometrial development and remode ling for blastocyst attachment and trophoblast invasion during the luteal p hase of the menstrual cycle. Due to species differences, the human is by fa r the best model per se by which to study human endometrial receptivity. Te chniques have evolved to obtain in vivo data on endometrial receptivity usi ng hysteroscopy, ultrasonography or magnetic resonance imaging. Despite spe cies differences, comparative studies of mammalian models and tissue- and c ell culture models using endometrial tissue or cells harvested at particula r phases of the reproductive cycle, or following experimental manipulation, have been used productively to study endometrial function. Differences as well as similarities have proven to be instructive. Such models have been u sed to study a variety of entities, such as homotypic and heterotypic cell- cell interaction, the role of steroids, cytokines, growth factors, immunomo dulatory agents and pharmacological substances. These models have also been used to study cellular, biochemical and molecular mechanisms involved with uterine receptivity. This chapter teas designed to provide a critical revi ew of contemporary literature relating to in vivo models and laboratory str ategies and paradigms for the study of uterine receptivity for blastocyst i mplantation.