Live birth rate after preimplantation genetic testing for aneuploidy versus conventional in vitro fertilization among couples with recurrent implantation failure: a pragmatic randomized controlled clinical trial

INTERVENTION: PGT‐A group:blastocyst morphologic score, blastocyst biopsy, NGS sequencing, single thawed blastocyst transfer ;ICSI group:blastocyst morphologic score, single thawed blastocyst transfer ; CONDITION: recurrent implantation failure PRIMARY OUTCOME: Live birth rate after initial transfer; SECONDARY OUTCOME: good birth outcome ;biochemical pregnancy rate;clinical pregnancy rate;ongoing pregnancy rate;rate of biochemical pregnancy loss;rate of clinical pregnancy loss;rate of multiple pregnancy ;birth weight ;risk of maternal complications ;risk of neonatal complications ; INCLUSION CRITERIA: 1. Infertile women with a history of RIF, RIF refers to failure to achieve a clinical pregnancy after one of the following conditions with all embryos transferred being of good quality: 1) 3 or more embryo transfer cycles; 2) 2 embryo transfer cycles where no less than three embryos were transferred cumulatively; 2. Women under the age of 38 when oocytes were retrieved; 3. Women having at least 2 good‐quality blastocysts on day 5 of embryo culture.