P-162 Numeric Embryo Quality Scoring Index (NEQsi) is Predictive of IVF Cycle Outcome at any Endometrial Thickness

Abstract

Listen

Translate article

Abstract Study question Is it possible to use NEQsi to determine the statistical contributions of embryo quality and endometrial thickness (ET) to IVF cycle outcome? Summary answer Yes. Analytics revealed that the likelihood of pregnancy is reliably predicted by the quality of the embryo at any endometrial thickness. What is known already ET is widely utilized to assess the quality of endometrial preparation in IVF cycles. The connection between endometrial thickness and cycle outcome is divided in the literature; studies report correlation between ET and cycle outcome while others find no link between the two. Regardless, the statistical interactions between ET and embryo quality remain understudied. NEQsi was recently developed as a method for converting Gardner embryo grades to interval variables for use in statistical modeling. The combination of NEQsi scores and endometrial thickness measurements provides an opportunity to assess the contributions of embryo quality and ET on IVF cycle outcomes. Study design, size, duration We conducted a retrospective analysis including IVF cycles conducted at a Canadian multi-clinician fertility care centre (n = 1623). Data were acquired from a chart review of deidentified patient files from 2014 – 2021. Participants/materials, setting, methods Participants were all patients who underwent single embryo transfer and had endometrial thickness measurements, Gardner embryo grading, and ultrasound based endometrial receptivity testing (usER) as part of their care program. No interventions were made. Gardner embryo grades on file were created using EmbryoScope (Vitrolife, Göteborg Sweden) and converted to NEQsi scores. We conducted multivariate statistical modelling analysis to determine the combined contribution of embryo grade and endometrial thickness on IVF cycle outcome. Main results and the role of chance NEQsi scores ranged from 3 – 11 (mean 8.32 ± 1.78 SD). Endometrial thicknesses ranged from 3.1 mm to 20.2 mm (mean 9.69 ± 2.23 SD). A positive linear relationship was observed between NEQsi score and probability of pregnancy. Multivariate logistical regression determined that embryo grade was a highly significant predictor of cycle outcome (p < 0.0001). Endometrial thickness was not a statistically significant predictor of cycle outcome (p = 0.585). Limitations, reasons for caution We acknowledge that the single centre design is a limitation of this study. Future investigation with more cycles and multiple centres will strengthen the study and interpretation of the data. Wider implications of the findings The application of NEQsi was simple and this work confirms the utility of the NEQsi in conducting statistical analyses with embryo quality as a covariate. In addition, our findings imply that cancellation of embryo transfers based on ET measurements may not be warranted. Trial registration number Not applicable