title: Clinical value of early cleavage embryo.
abstract: OBJECTIVE
  This study was undertaken to see if embryo transfer containing early cleavage embryos resulted in better clinical pregnancy rate.
  
  
  METHODS
  The treatment outcomes of IVF-ET were retrospectively reviewed. Out of 258 transfer cycles, 160 cycles contained no early cleavage embryos (Group I) and 98 cycles contained at least one early cleavage embryo (Group II). The definition of early cleavage embryo is the presence of two blastomeres 24-26 h after insemination. The implantation rate, clinical pregnancy rate were compared between two groups. Student's t-test and the Mann-Whitney U-test were used for continuous variables, and the Chi-squared (chi(2)) test was used for binary variables. Differences were considered statistically significant at P<0.05.
  
  
  RESULTS
  The implantation rate and clinical pregnancy rate were 11.6% and 25.6% in Group I, 18.6% and 38.8% in Group II (P<0.05).
  
  
  CONCLUSIONS
  Early cleavage embryos possess greater implantation potential. Embryo transfer containing early cleavage embryos had a better clinical pregnancy rate.
authors.affiliation: Department of Obstetrics and Gynecology, Chi Mei Foundation Hospital, 71010, Tainan, Taiwan. yung0613@ms2.hinet.net
authors.forename: Y C
authors.initials: YC
authors.lastname: Tsai
authors.forename: M T
authors.initials: MT
authors.lastname: Chung
authors.forename: Y H
authors.initials: YH
authors.lastname: Sung
authors.forename: T F
authors.initials: TF
authors.lastname: Tsai
authors.forename: Y T
authors.initials: YT
authors.lastname: Tsai
authors.forename: L Y
authors.initials: LY
authors.lastname: Lin
mesh_terms: D000328:Adult; D002970:Cleavage Stage, Ovum / Q000502:physiology* / Q000637:transplantation; D010064:Embryo Implantation; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D006801:Humans; D011247:Pregnancy; D011256:Pregnancy Outcome; D018873:Pregnancy Rate; D012015:Reference Standards; D012189:Retrospective Studies; D013997:Time Factors