P-146 Blastocyst morphometry and morphology predict ploidy

Abstract

Abstract Study question Are objective measurements and subjective assessments of blastocysts predictive of aneuploidy? Summary answer Aneuploidy was predicted equally well by lower trophectoderm cell count (objectively measured morphometry) or by a lower subjective trophectoderm grade. What is known already Blastocyst morphological grade has been reported to be moderately predictive of embryo ploidy. However, due to its subjective nature, morphological grade may be significantly more difficult to code into artificial intelligence algorithms when compared to objective measurements. Study design, size, duration This retrospective cohort study included all 1409 blastocysts that were subject to pre-implantation genetic testing (PGT) in a 30-month study period. Participants/materials, setting, methods Per clinic routine, embryos from oocyte were cultured to the blastocyst stage following conventional ovarian stimulation, oocyte retrieval, and intracytoplasmic sperm injection. If the patients opted for PGT, a laser was used to open the zona at the cleavage stage, trophectoderm biopsies were collected at the blastocyst stage, and biopsies were analyzed by next-generation sequencing. Inner cell mass sizes were measured by ocular micrometer and trophectoderm cells were counted in one plane of focus. Main results and the role of chance The mean patient age (including oocyte donors) was 31.9±6.4 years and the mean number of collected oocytes was 23.0±12.9. In multivariable logistic regression, greater patient age was the best available predictor of blastocyst aneuploidy (P < 0.0001). Along with age in the model, the observation of fewer trophectoderm cells (P = 0.0019) was also predictive of aneuploidy. Alternatively, the failure to have an A-grade trophectoderm (P = 0.0007) was also predictive of aneuploidy, also with age in the model. Neither the objectively measured inner cell mass size nor subjective inner cell mass grade were significant predictors of ploidy. Overall, objectively measured blastocyst morphometry was about equally predictive of ploidy as was subjective blastocyst grading, and area under the receiver operating characteristic curve was 0.62 for each model. Limitations, reasons for caution This study was retrospective, allowing the possibility of selection bias among patients and among embryos chosen for biopsy. Wider implications of the findings Artificial intelligence algorithms assessing embryos might benefit from the similar performance of subjective grading and objective measurements, because it is much easier to code objective measurements into the algorithms. Trial registration number None.