A systematic review and meta-analysis of double trophectoderm biopsy and/or cryopreservation in PGT: balancing the need for a diagnosis against the risk of harm.

This article systematically reviews and meta-analyzes the safety and reproductive outcomes associated with multiple embryo manipulations—specifically double cryopreservation and/or double trophectoderm biopsy—in preimplantation genetic testing (PGT). The study compares two workflows involving double manipulations, double cryopreservation with single biopsy (CBC) and double biopsy with double cryopreservation (BCBC), against the standard single biopsy and single cryopreservation (BC) approach. Results from 10 retrospective studies indicate that both CBC and BCBC are associated with significantly lower live birth rates and clinical pregnancy rates per embryo transfer, alongside higher miscarriage rates, compared to BC, although cryo-survival and perinatal outcomes remain within normal ranges. The review emphasizes the need to balance the potential risks of additional embryo manipulations against the benefits of avoiding transfer of genetically affected embryos and calls for standardized laboratory protocols, operator training, and further research to optimize PGT practices.