Diverging guidelines and consensus statements on preimplantation genetic testing for aneuploidy: indications and strategies reviewed

Preimplantation genetic testing for aneuploidy (PGT-A) is widely used to screen for embryo aneuploidy, enabling the selection and transfer of genetically normal embryos. Despite its potential to improve clinical outcomes, the implementation of PGT-A raises challenges, including variability in clinical indications, protocols, interpretation of results, and post-PGT counselling. To better explore the extent of standardization and consistency in PGT-A practice, this study undertook a comparative analysis of recommendations from widely adopted guidelines, opinion papers, and position statements on PGT-A, emphasizing both convergent views and points of divergence. Thus, the impact of variability in PGT-A practice has been assessed by reviewing the technical and clinical approaches established by n = 11 authoritative scientific societies. Recommendations from widely adopted guidelines, opinion and position papers were compared, highlighting areas of both consensus and divergence. Advanced maternal age is the only indication to PGT-A proposed in the committee opinion of the American Society for Reproductive Medicine and in general all the societies concur with this opinion. However, recurrent implantation failure and recurrent miscarriages are also indications for PGT-A according to 4 societies and male factor infertility by 3 societies. Comparative genomic hybridization is one of the recommended testing platforms by 6 societies while the more recent documents tend to support the use of next generation sequencing or single nucleotide polymorphism array. Approaches to managing mosaic embryo transfers differ, with only some societies providing criteria for embryo prioritization or defining thresholds for the degree of mosaicism. Similarly, there is no uniform guidance on prenatal testing of pregnancies following PGT-A. None of the guideline or document herein presented was able to label recommendation with a grade assigned based on the strength of the supporting evidence. As medical knowledge and evidence evolve rapidly in PGT-A and robust data from RCTs is scarce, proposing specific recommendations is very challenging. Older guidelines may not reflect the most recent research findings or technological advancements, which can significantly affect their relevance and accuracy.