INTRODUCTION: In ICSI and conventional IVF cycles, the embryos are usually selected for transfer based on evaluation of the cleavage speed and the extent of blastomere fragmentation. Pronuclear stage scoring system has been used in IVF recently as an additional parameter. OBJECTIVES: The aim of this study was to classify embryos from ICSI cycles according to the pronuclear scoring system and its influence on implantation rate. MATERIAL AND METHODS: 62 couples suffering from different types of infertility and treated by ICSI were included in our study. For each embryo, the following data were analyzed: pronuclei (PN) morphology, 16-20 hours after ICSI, and embryo morphology, about 40-42 (day 2) and 65-68 (day 3) hours after ICSI. The embryo transfer was performed on the third day after pick-up. RESULTS: In 55 (88.7%) cases we transferred at least one embryo from the zygotes of 0 or 1 or 2 pattern. The implantation rate was 30.6% (n = 19). In all of these cases the embryos have been derived from zygotes from pattern 0, 1 or 2. CONCLUSIONS: Pronuclear scoring system of zygotes appears to be a predictor of the implantation potential. Embryos derived from pattern 0, 1 and 2 of zygotes implant at a higher rate (p = 0.05).
INTRODUCTION: In ICSI and conventional IVF cycles, the embryos are usually selected for transfer based on evaluation of the cleavage speed and the extent of blastomere fragmentation. Pronuclear stage scoring system has been used in IVF recently as an additional parameter. OBJECTIVES: The aim of this study was to classify embryos from ICSI cycles according to the pronuclear scoring system and its influence on implantation rate. MATERIAL AND METHODS: 62 couples suffering from different types of infertility and treated by ICSI were included in our study. For each embryo, the following data were analyzed: pronuclei (PN) morphology, 16-20 hours after ICSI, and embryo morphology, about 40-42 (day 2) and 65-68 (day 3) hours after ICSI. The embryo transfer was performed on the third day after pick-up. RESULTS: In 55 (88.7%) cases we transferred at least one embryo from the zygotes of 0 or 1 or 2 pattern. The implantation rate was 30.6% (n = 19). In all of these cases the embryos have been derived from zygotes from pattern 0, 1 or 2. CONCLUSIONS: Pronuclear scoring system of zygotes appears to be a predictor of the implantation potential. Embryos derived from pattern 0, 1 and 2 of zygotes implant at a higher rate (p = 0.05).