P-507 Prediction of clinical efficacy of PGT-A based on maternal age and embryo quality in patients with recurrent implantation failure (RIF) or recurrent pregnancy loss (RPL)
Authors: Kim J  W , Lee S  Y , Hur C  Y , Lim J  H 
Published: July 2024

Abstract

Study question
Can the utility of PGT-A be predicted by selecting embryos based on both maternal age and embryo quality in patients with RIF or RPL?

Summary answer
The predictive value of PGT-A can potentially be determined by assessing maternal age and embryo quality of experiencing patients with RIF or RPL.

What is known already
Embryo quality and euploid status are crucial determinants in selecting embryos for euploid embryo transfer to achieve a successful pregnancy. This is because embryos with high morphological scores may still exhibit aneuploidy, making morphologic evaluation alone limited. This limitation is particularly important in patients with a history of RIF and RPL. Aneuploidies occur during meiosis in the embryo and increase significantly with age, becoming a major contributor to implantation failure, leading to unsuccessful pregnancies, miscarriages, and congenital birth defects.

Study design, size, duration
This retrospective study, conducted at a single center, assessed embryo quality in 927 blastocysts derived from 221 cases of patients with RIF and 863 blastocysts derived from 204 cases of patients with RPL. The study spanned from January 2022 to November 2023. Blastocysts were scored using the KIDScore provided by the Embryoscope® time-lapse system (Vitrolife, Göteborg, Sweden) following the manufacturer’s protocols and subsequently underwent next-generation sequencing (NGS)-based PGT-A.

Participants/materials, setting, methods
A total of 927 RIF and 863 RPL patients’ blastocysts were analyzed, resulting in 256 and 242 euploid embryos, respectively, using NGS. Euploid embryos were classified by morphokinetics (good quality and medium quality) and maternal age groups (≤35, 36-37, 38-39, 40-41, 42-43, 44-45, ≥46). In RIF, 62.9% (161/256) of euploid embryos were classified as good quality, and 37.1% as medium quality. In RPL, 59.1% (143/242) were classified as good quality, and 40.9% as medium quality.

Main results and the role of chance
The euploid embryo rate decreases in both good- and medium-quality embryos as the patient’s age increases. For RIF patients: ≤35 (47.1% and 22.7%), 36-37 (46.7% and 19.8%), 38-39 (37.5% and 16.4%), 40-41 (37.5% and 11.5%), 42-43 (31.8% and 10.0%), 44-45 (0% and 11.1%), ≥46 (0% and 0%). For RPL patients: ≤35 (46.0% and 25.4%), 36-37 (45.9% and 25.0%), 38-39 (43.8% and 15.1%), 40-41 (27.9% and 18.0%), 42-43 (26.3% and 11.7%), 44-45 (0% and 12.5), ≥46 (0% and 0%). Moreover, ongoing pregnancy or live birth rates also decrease as the patient’s age increases, while the miscarriage rate increases. For RIF patients: ≤35 (57.8% and 16.1%), 36-37 (50.0% and 18.8%), 38-39 (46.2% and 25.0%), 40-41 (43.5% and 28.6%), 42-43 (36.4% and 33.3%), 44-45 (0% and 100%). For RPL patients: ≤35 (59.5% and 12.0%), 36-37 (52.0% and 18.8%), 38-39 (47.8% and 31.3%), 40-41 (43.5% and 37.5%), 42-43 (40.0% and 42.9%), 44-45 (0% and 100%). However, embryo transfer was not possible for those over 46 due to all embryos being aneuploidy.
Therefore, PGT-A is valuable for patients under 42, proves beneficial for reducing the abortion rate, and achieving a high pregnancy rate for those aged 42-43, and should be considered for patients over 44.

Limitations, reasons for caution
This data is from a retrospective study, and well-designed prospective studies with data from multiple centers, larger samples, and extended study periods are needed to validate the current results. Additionally, obtaining information on demographic characteristics, detailed embryo information, and overall clinical outcomes can further enhance the current results.

Wider implications of the findings
These findings suggest that individualizing each case based on both maternal age and embryo quality is helpful in predicting the utility of PGT-A. Such personalized considerations can result in significant benefits for patients by optimizing outcomes, reducing cycle times, and consequently lowering related costs.

Trial registration number
not applicable