PGT-A: who and when? Α systematic review and network meta-analysis of RCTs

BSTRACT Purpose Wide controversy is still ongoing regarding efficiency of preimplantation genetic testing for aneuploidy (PGT-A). This systematic review and meta-analysis, aims to identify the patient age group that benefits from PGT-A and the best day to biopsy. Methods A systematic search of the literature was performed on MEDLINE/PubMed, Embase and Cochrane Central Library up to May 2020. Eleven randomized controlled trials employing PGT-A with comprehensive chromosomal screening (CCS) on Day-3 or Day-5 were eligible. Results PGT-A did not improve live-birth rates (LBR) per patient in the general population (RR:1.11; 95%CI:0.87-1.42; n=1513; I 2 =75%). However, PGT-A lowered miscarriage rate in the general population (RR:0.45; 95%CI:0.25-0.80; n=912; I 2 =49%). Interestingly, the cumulative LBR per patient was improved by PGT-A (RR:1.36; 95%CI:1.13-1.64; n=580; I 2 =12%). When performing an age-subgroup analysis PGT-A improved LBR in women over the age of 35 (RR:1.29; 95%CI:1.05-1.60; n=692; I 2 =0%), whereas it appeared to be ineffective in younger women (RR:0.92; 95%CI:0.62-1.39; n=666; I 2 =75%). Regarding optimal timing, only day-5 biopsy practice presented with improved LBR per ET (RR: 1.37; 95% CI: 1.03-1.82; I 2 =72%). Conclusion PGT-A did not improve clinical outcomes for the general population, however PGT-A improved live-birth rates strictly when performed on blastocyst stage embryos of women over the 35-year-old mark.