Clinical Significance of Cumulative Embryo Score As a Predictor of Pregnancy in IVF-ET Patients Undergoing ICSI

Kim, S H; Jung, B J; Jae, B C; Kim, H S; Ryn, B Y; Oh, S K; Suh, C S; Choi, Y M; Kim, J K; Moon, S Y; Lee, J Y

Abstract

In in vitro fertilization and embryo transfer[IVF-ET] program, the cumulative embryo score[CES] system involves three aspects of relevance in embryos for the achievement of pregnancy : cleavage rates, morphological qualities and number of embryos transferred. The objective of this retrospective study was to determine the cut-off value of CES influencing the occurrence of pregnacy outcome in IVF-ET patients undergoing intracytoplasmic sperm injection[ICSI]. A total of 153 cycles of IVF-ET augmented with ICSI was performed in 69 patients from May, 1995 and June, 1997. Both the total and clinical pregnancy rates were progressively increased with CES, with the highest pregnancy rates in group with CES 60~79.A highly significant difference was obserbed in the average CES between the pregnant[68.3+/-35.8] and nonpregnant[49.5+/-29.2] groups[p<0.01]. In addition, mean CES in pregnant patients was consistently higher, irrespective of the number of embryos transferred. From our data, it is suggested that the minimum number of embryos to be transferred for the achievement of pregnancy was 3 for patients less than 30 years old, 4 for 30~34 years, and 5 for more than 35 years. In conclusion, the CES system is a good indicator of cumulative embryo quality as expressed by the achievement and outcome of pregnancy in IVF-ET patients undergoing ICSI.