One of the main factors in the success of in-vitro fertilization is the quality of the environment of the embryo. In contrast to maternal age, the environment in which the embryo develops is a modifiable factor. Many techniques, such as assisted hatching and perfecting culture media have been attempted in order to reproduce as much as possible the natural, physiological environment of the mother for the embryo in in-vitro fertilization. However, the different new culture media used are devoid of growth factors normally secreted by uterine cells that enhance the interaction between the embryo and its environment.