Embryo score is a better predictor of pregnancy than the number of transferred embryos or female age

Objective: To compare the value of 17 IVF variables, including a new mean s core of transferred embryos (MSTE), in predicting pregnancy rate. Design: Retrospective study. Setting: Private IVF unit. Patient(s): Women who underwent 10,000 embryo transfers. Main Outcome Measure(s): Duration of infertility, type of infertility, fema le age, rank of IVF attempt, type of ovarian treatment, progesterone level, sperm count, sperm motility, sperm morphology, number of retrieved oocytes , number of mature oocytes, maturation rate, number of embryos obtained, fe rtilization rate, number of transferred embryos, cumulative embryo score (C ES), mean score of transferred embryos (MSTE), and pregnancy rate. Result(s): Outcome of IVF-ET was significantly correlated with female age, type of infertility, number of retrieved oocytes, number of mature oocytes, maturation rate, embryos obtained, fertilization rate, transferred embryos , CES, and MSTE. Multivariate analysis demonstrated that MSTE was a better predictor of pregnancy than the number of transferred embryos and female ag e. Conclusion(s): Embryo quality is the best predictor of pregnancy. The embry o score described herein should be used in IVF-ET programs to choose the be st embryos for transfer. (C) 2001 by American Society for Reproductive Medi cine.