title: A prospective randomized comparison of early embryo cleavage kinetics between two media culture systems.
abstract: OBJECTIVE
  To investigate whether early embryo cleavage kinetics were affected by type of culture media.
  
  
  METHODS
  In this prospective sibling-split study, 620 oocytes from 37 patients were randomly allocated into two groups: Cook group and Vitrolife group. Oocytes/embryos in Cook group, would be cultured with Cook sequential culture medium, while oocytes/embryos in Vitrolife group, would be cultured with Vitrolife sequential culture medium. Time-lapse imaging technology was used to calculate exact timing of early embryo cleavage events which included time to 2PN breakdown, cleavage to 2-, 3-, 4-, 5- cell and the time duration in the 2-,3-cell stage. Then these timing of early embryo cleavage events were compared between Cook group and Vitrolife group. Moreover, fertilization rate, cleavage rate, high quality embryo rate, usable blastocyst rate, pregnancy rate and implantation rate of these two groups were also analyzed.
  
  
  RESULTS
  The results showed there were no differences in all timing of early embryo cleavage events between the two groups. In addition, the two groups were similar in fertilization rate (Cook 71.0% vs. Vitrolife 71.3%, P>0.05), cleavage rate (Cook 98.1% vs. Vitrolife 98.2%, P>0.05), high quality embryo rate (Cook 52.1% vs. Vitrolife 52.7%, P>0.05), usable blastocyst rate (Cook 29.7% vs. Vitrolife 28.0%, P>0.05), pregnancy rate (Cook 46.7% VS. Vitrolife 50.0%, P>0.05) and implantation rate (Cook 30.3% VS. Vitrolife 29.0%, P>0.05).
  
  
  CONCLUSIONS
  Morphokinetics used for embryo selection are not affected by the two different culture media.
authors.affiliation: Huan Zhang, MD, Department of Reproductive Medical Center, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China.
authors.forename: Huan
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Yi Zheng, MD, Department of Reproductive Medical Center, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: Yonggen Wu, MD, Department of Reproductive Medical Center, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China.
authors.forename: Yonggen
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Danna Ye, MD, Department of Reproductive Medical Center, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China.
authors.forename: Danna
authors.initials: D
authors.lastname: Ye
authors.affiliation: Xuefeng Huang, PhD, Department of Reproductive Medical Center, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China.
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Huang
keywords: Culture media; Embryonic development; Morphokinetics; Time-lapse imaging