摘要Objective To investigate the effect of the glucose-free reimplantation stage one(P1) medium and the ECM medium on embryo development quality in IVF.Methods The patients with ≥4 zygotes of 2PN were studied.A total of 201 retrieval cycles were included in a prospective randomized study.Each patient was herself control Half of zygotes of 2PN were transferred into ECM medium(group A)and half into P1 medium(group B)for further culture.Embryo development was evaluated on the day of embryo transfer.The efficacy of ECM was compared with P1 as culture medium for the development of preimplantation embryos.Results No statistically significant differences were noted between the two groups regarding embryo-cleavage rate(97.13% vs 97.55%)and rate of normal-cleaving embryos(58.29% and 58.37%).The rate of top-quality embryos was statistically higher in group A than in group B(27.59% vs 19.75%,P＜0.05).Embryo quality,as assessed by morphological parameters(the amount of detached anuclear fragments＞30%),was better in group A than in group B(19.86% vs 21.75%),however,there was no statistically significance.Both the rate of good-quality embryos(47.95% vs 46.17%)and available embryos(63.22% vs 61.,9%)were higher in group A than in group B,but there was also no statistically significance.Conclusion The ECM medium may be associated with a better embryo quality compared with the P1 medium.