Perifollicular vascularity and its relationship with oocyte maturity and IVF outcome.

New markers of embryo ability to implant are pursued continuously. Understanding whether an oocyte is really "mature," that is, ready to be fertilized, would be of great help in choosing an embryo that will implant. It is usual to pay attention to the phase of meiosis, considering the extrusion of the polar body (metaphase II) to be the only sign of the maturity of the oocytes. Nevertheless, understanding more about how the cytoplasm contributes to an oocyte's competency also shows promise as a method of predicting which embryos will implant. Some studies about perifollicular vascularity have demonstrated that embryos originating from oocytes developed in well-vascularized follicles have a higher implantation rate than those originating from oocytes developed in follicles with poor vascularization. Here, we report our results from a preliminary study in which embryos were transferred according to the degree of vascularization of the follicle. Women who received embryos originating from oocytes developed in well-vascularized follicles had a statistically higher pregnancy rate than women who received embryos deriving from oocytes grown in more poorly vascularized follicles (34% vs. 13.7%).