Accuracy of a combined score of zygote and embryo morphology for selecting the best embryos for IVF / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

ABSTRACT

<p><b>OBJECTIVE</b>To evaluate the accuracy of a scoring system combining zygote and embryo morphology in predicting the outcome of in vitro fertilization (IVF) treatment.</p><p><b>METHODS</b>In a study group, 117 consecutive IVF or intracytoplasmic sperm injection (ICSI) cycles with embryo transfer were carried out and 312 embryos were scored using a combined scoring system (CSS) of zygote and embryo morphology before transplantation. In a control group, a total of 420 IVF or ICSI cycles were carried out and 1176 embryos were scored using a cumulative embryo score (CES). The effects of the combined scoring system on the embryo implantation rate and pregnancy rate per cycle were analyzed.</p><p><b>RESULTS</b>Using the combined scoring system, the embryo implantation rate (27.6%) and the clinical pregnancy rate (48.7%) were significantly higher than those in the control group (20.8% and 38.6%, respectively). Also, the implantation rate of embryos scoring>or=70 (38.5% 82 sacs/213 embryos) was significantly higher (P<0.001) than that of embryos scoring<70 (4% 4 sacs/99 embryos). The pregnancy rate of patients with embryos scoring>or=70 using the combined scoring system (66.7%) was significantly higher (P<0.001) than that of patients with embryos scoring>or=20 using the cumulative embryo score (59.0%).</p><p><b>CONCLUSION</b>The results suggest that selecting embryos with a high score (>or=70) using the combined scoring system could increase the implantation rate and pregnancy rate, and that using a scoring system combining assessments of human zygotes and pre-implantation embryos might predict IVF outcomes more accurately than using a cumulative embryo score.</p>