Repeated implantation failure and fetal growth restriction in patients undergoing IVF: a retrospective cohort study

What exactly do we mean by ‘recurrent implantation failure’? A systematic review and opinion

“…The second most common definition used was 'two or more failed treatment cycles' which was used in 25 studies. In this group, the treatment cycle involved the use of IVF in 11 cases (Chou et al, 2011;Fukui et al, 2006;Gianaroli et al, 1997;Huang et al, 2011;Ivanov et al, 2012;Kalu et al, 2008;Martinuzzo et al, 2005;Matsubayashi et al, 2001;Sermondade et al, 2012;Spandorfer et al, 2002;Vaquero et al, 2006), ICSI in two cases (Berker et al, 2011;Oliveira et al, 2011), IVF or ICSI in two cases (Eyheremendy et al, 2010;Lodigiani et al, 2011) and was not clarified in 10 studies (Foulk et al, 2007;Hiraoka et al, 2008;Kahraman et al, 2000;Petersen et al, 2005;Schoolcraft et al, 2010;Stephenson and Fluker, 2000;Takahashi et al, 2011;Tsoumpou et al, 2010;Urman et al, 2009;Valojerdi et al, 2008). Six of the authors identified the transferred embryos as being 'fresh and or frozen' (Eyheremendy et al, 2010;Hiraoka et al, 2008;Petersen et al, 2005;Stephenson and Fluker, 2000;Takahashi et al, 2011;Urman et al, 2009).…”

“…The outcomes of treatment, which defined each unsuccessful cycle, were stated in 42 of all studies. The most frequently stated outcome was 'failure to achieve a pregnancy' which was used in 21 studies (Achache et al, 2010b;Carp et al, 1994;Creus et al, 1998;Dos Santos et al, 2012;Friedler et al, 2007;Kalu et al, 2008;Ledee et al, 2008;Quenby et al, 2007Quenby et al, , 2009Raziel et al, 2002Raziel et al, , 2007Sharif and Ghunaim, 2010;Stein et al, 1995;Taranissi et al, 2005;Tremellen and Russell, 2011;Tsoumpou et al, 2010;van den Heuvel et al, 2007;Vialard et al, 2008;Voullaire et al, 2002;Wilton et al, 2003;Yakin et al, 2008). A negative serum b-HCG 2 weeks following embryo transfer was used to define treatment outcome by eight authors (Coulam et al, 2006;Debrock et al, 2009;Firouzabadi et al, 2009;Goodman et al, 2008Goodman et al, , 2009Sacks et al, 2012;Sauer et al, 2010;Urman et al, 2009).…”