Recurrent implantation failure: definition
An attempt to define recurrent implantation failure.
Numerous definitions of recurrent implantation failure exist. The complexity and redundancy of the process of implantation makes a single definition difficult to determine.
Each center must establish a definition of recurrent implantation failure based upon the data from that center. The definition of RIF used in our program requires the transfer of ≥8, 8-cell stage embryos or ≥5 blastocyst embryos.