Optimizing embryo transfer technique for recurrent implantation failure management

The enigmatic condition of recurrent implantation failure (RIF) may be much related to conditions that characterize the reproductive process in the human species. With optimal fertility in the second and third decade of life, a rapid decline is observed in the fourth, resulting in a state of natural sterility on average in the early forties. The majority of explanatory factors seem to be present in the female, as males tend to have uncompromised fertility up to the age of 50, with a slow decline thereafter. Factors that are believed to highly contribute to the limited fertile lifespanin the human female are oocyte and subsequent embryo quality, for which the mechanisms are largely unknown.^1–3 Next to embryonic aneuploidy, mostly related to meiotic errors, many other failures in the oocyte-follicle complex maycontributeto the overall low, and with age rapidly declining, quality of the human embryo.^4,5 Still, aging ordysfunction of the endometrium may have a certain degree of contribution, although oocyte donation studies have excluded a major role at this level.