Recurrent implantation failure: the role of the endometrium.

The success rate of reproductive treatment methods depends on many different factors. The most important and discussed ones in the literature are maternal age, the causes of infertility, the ovarian response to stimulation, the influence of the male factor and sperm quality, embryo quality and the various uterine pathologies. Some couples fail repeatedly after transferring good quality embryos without any obvious reason and this becomes a major continuing problem after IVF/ICSI procedures. It can be speculated that in these couples, insufficiency of the endometrium might be a possible reason for implantation failure. This review article summarized current literature describing the consecutive endomertial procedures involved in successful embryo implantation. It is believed that efforts to align criteria for definition of recurrent implantation failure (RIF) and attempts to classify different RIF types would develop guidelines for treatment procedures which would result in an increase in patients' opportunities to conceive.