Non-invasive chromosome screening of embryos fertilized in vitro: A single center, retrospective study

Objective: To evaluate the center’s experience with non-invasive preimplantation genetic testing for aneuploidy (NIPGT-A), focusing on embryo aneuploidy assessment, euploidy-linked pregnancy outcomes, and the relationship between embryo morphology and chromosomal status. Methods: A retrospective study was conducted on couples undergoing in-vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycles that yielded day-5 blastocysts eligible for NIPGT-A. Spent culture media from 159 blastocysts were analyzed using multiple annealing and looping-based amplification cycles (MALBAC)-based whole genome amplification followed by next- generation sequencing with a 10 Mb resolution threshold for copy- number variation detection. Embryo ploidy was categorized as euploid, low mosaic, high mosaic, or aneuploid based on cell- free DNA (cfDNA) abnormality levels. Euploid embryos were transferred in subsequent frozen embryo transfer (FET) cycles. Clinical outcomes included biochemical pregnancy, clinical pregnancy, ongoing pregnancy, and live birth rates. Results: Fifty couples were included in this study. Among 213 blastocysts formed, 159 (74.7%) underwent NIPGT-A. Of these, 43.4% were euploid, 19.5% aneuploid, 23.3% mosaic, and 13.8% uninterpretable. A total of 82 embryos were transferred across 45 FET cycles, including euploid (69), mosaic (7), and uninterpretable (6) embryos. The clinical pregnancy rate was 53.3%, with a biochemical loss rate of 6.7% and early pregnancy failure of 4.4%. Ongoing pregnancy occurred in nearly half of the participants, and several successful outcomes were documented even among mosaic and uninterpretable embryos. Embryo morphology did not correlate significantly with euploidy, reaffirming the limited predictive value of morphologic grading alone. Conclusion: NIPGT-A is a feasible, safe, and clinically meaningful alternative to invasive PGT-A, offering favorable pregnancy outcomes while avoiding embryo manipulation. Although technical limitations such as cfDNA variability and uninterpretable results persist, NIPGT-A enhances embryo selection, reduces miscarriage risk, and is particularly beneficial in low-yield or high-risk IVF populations. Continued refinement of laboratory protocols and long-term outcome studies are essential for broader clinical adoption.