ABSTRACT
This study was designed to evaluate the applicability of the pronuclear scoring system [2-score] alone, or in combination with maternal variables to predict embryo grade determined on day 3 from a large number of embryos derived from patients undergoing treatment with IVF and/or ICSI. The study included 92 couples assigned to undergo NF or ICSI for primary [66.3%] or secondary [33.7%] infertility due to male factor in 30.4%. female factor in 55.5% or unexplained infertility in 14.1 %. A total of 500 zygotes of a total of 611 oocytes were evaluated for 2-scoring at 16-1 8 hours after fertilization and followed for embryo grading on day 3 for evaluation of statistical relation between both and to determine the specificity and sensitivity of Z-score and certain maternal variables in such relation. There were 265, 172, 43 and 20 zygotes of 2-1, 2-2, 2-3 and 2-4 scores. Using regression analysis, 2-scoring showed highly significant [P=0.000] difference in comparison to other variables in prediction of the embryo grade on day 3 and showed high specificity as determined using the receiver operating characteristic [ROC] curve analysis. It could be concluded that the pronuclear scoring sys tern of zygotes is a specific predictor of the embryo grade on day 3 after n/F and/or ICSI and significantly aid for selection of top quality embryo