Search strategy
EMBASE (1980 to January 2021) and PubMed (1950 to January 2021) were systematically searched as well as the reference lists of the selected articles. Initially, a search was conducted for comparative studies comparing the pregnancy outcomes in the carriers and noncarriers with RPL. Next, a search was conducted to compare the pregnancy outcomes after attempting EM with those after performing PGD in the RPL carriers. ‘Recurrent pregnancy loss’ , ‘chromosome abnormalities’, ‘reproductive outcome’ ,‘parental’ and ‘preimplantation genetic diagnosis’ were used as keywords in the searches performed by a clinical librarian (JJ.H.). The appendix shows the search strategies in EMBASE, and adapted for PubMed, which were used to investigate the pregnancy outcomes between carriers and noncarriers and after EM or PGD in RPL carriers.