“…Studies concerned either autologous cycles (13, 14, 19, 21, 22, 25, 27, 29-32, 36, 38-43, 45, 47), oocyte donation (20,44) or not specified (11, 21, 23, 26, 28, 33-35, 37, 46). Studies included single-embryo transfers (11,13,22,28,33,35,40,41), single-or double-embryo transfers (19,20,26,27,30,31,34,37,46), transfers of two to three embryos (24), transfers of three to four embryos (38,39,44) and not reported (14,21,23,25,29,36,43,45,47). Transferred embryos were cleaved embryos (21,24,27,29,34,39), blastocyst embryos (11,13,14,19,20,22,23,26,…”