title: Successful pregnancy following the transfer of vitrified blastocyst which developed from poor quality embryos on day 3.
abstract: BACKGROUND
  The selection of pre-embryos for transferred is based on morphological appearance. But some poor quality cleaved embryos also can be cultured to the blastocyst stage and implanted.
  
  
  OBJECTIVE
  To assess the clinical pregnancy outcomes of blastocyst transfer which developed from poor quality embryos.
  
  
  METHODS
  A total of 109 cleaved embryos with poor quality were cultured to day 5/day 6 and 27 (24.8%) blastocysts were collected from the 15 cycles/patients undergoing conventional IVF. All the blastocysts were cooling with fast-freezing. Then the blastocysts were warmed for transfer.
  
  
  RESULTS
  All of 25 vitrified blastocysts (92.6%) survived after warming and were transferred to 15 patients. Five of the women became pregnant.
  
  
  CONCLUSIONS
  Our results suggest that vitrified human day 5/day 6 blastocyst transfer which develop from poor quality embryo at day 3 can contribute to increasing cumulative pregnancy rates in assisted reproduction.
authors.affiliation: Department of Assisted Reproductive Medical Center, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Sichuan, China.
authors.forename: Xiao-Jian
authors.initials: XJ
authors.lastname: Zhang
authors.affiliation: Department of Assisted Reproductive Medical Center, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Sichuan, China.
authors.forename: Ye-Zhou
authors.initials: YZ
authors.lastname: Yang
authors.affiliation: Department of Assisted Reproductive Medical Center, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Sichuan, China.
authors.forename: Li-Hua
authors.initials: LH
authors.lastname: Min
authors.affiliation: Department of Assisted Reproductive Medical Center, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Sichuan, China.
authors.forename: Qun
authors.initials: Q
authors.lastname: Lv
authors.affiliation: Department of Assisted Reproductive Medical Center, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Sichuan, China.
authors.forename: Pin
authors.initials: P
authors.lastname: Bai
authors.affiliation: Department of Assisted Reproductive Medical Center, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Sichuan, China.
authors.forename: Xiao-Jie
authors.initials: XJ
authors.lastname: Li
authors.affiliation: Department of Assisted Reproductive Medical Center, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Sichuan, China.
authors.forename: Mei-Xu
authors.initials: MX
authors.lastname: Liao
keywords: Poor quality embryos; Pregnancy; Vitified Blastocyst- transfer