Time-lapse imaging (TLI) versus preimplantation genetic testing (PGT): a scoping review on embryo assessment strategies

Background: Embryo selection remains a critical determinant in the success of assisted reproductive technologies (ART). While conventional morphological assessment is widely used, it lacks predictive precision and is prone to subjectivity. Two advanced technologies; Time-Lapse Imaging (TLI) and Preimplantation Genetic Testing (PGT) have emerged to enhance embryo viability assessment, yet their comparative effectiveness remains uncertain. This scoping review aimed to evaluate and compare the effectiveness of TLI and PGT in embryo selection for transfer, their impact on clinical outcomes, and the strengths and limitations of each method. Methods: A scoping review methodology based on PRISMA for scoping review 2020 guidelines was employed. Four databases PubMed, Scopus, Springer Link, and Cochrane Library were searched for articles published between 2014 and 2024. Results: A total of 20 eligible studies were included and analysed. TLI studies reported improved morphological assessment and non-invasive, real-time observation, with pregnancy rates ranging between 27.8% to 68% and live birth rates up to 45.9%. PGT, particularly PGT-A, showed superior outcomes in terms of implantation up to 76.8% and live birth rates up to 78.3%, especially among patients with recurrent pregnancy loss or advanced maternal age. However, PGT carries the risk of embryo damage due to its invasive nature and is associated with higher costs and longer processing times. TLI offers a safer and cost effective option for embryo selection with minimal risk to embryo integrity. TLI’s integration with software tools such as iDA scores has further enhanced its diagnostic capability. Nonetheless, in specific clinical scenarios like recurrent miscarriages or known genetic disorders, PGT remains indispensable. Conclusion: Both TLI and PGT offer significant advantages in embryo assessment. While TLI is favorable for routine, non-invasive monitoring, PGT provides critical genetic insights.