Repeated implantation failure: clinical approach.

Successful embryo implantation depends on a well-functioning endometrium as well as a normal healthy embryo. This process might be hampered if either of these variables is defective. Repeated implantation failure (RIF) is diagnosed when good-quality embryos repeatedly fail to implant after transfer in several IVF treatment cycles. The causes of RIF originate with either the mother or the embryo. The authors discuss factors that are associated with RIF and address various treatment options.