title: Effects of early-cleavage embryo transfer on in vitro fertilization-embryo transfer pregnancy outcomes.
abstract: OBJECTIVE
  To observe the effects of early-cleavage embryo transfer (ET) on pregnancy outcomes in vitro fertilization-embryo transfer (IVF-ET).
  
  
  METHODS
  The data of 6,548 two pro-nucleate (2PN) embryos and 968 patients who underwent IVF or intracytoplasmic sperm injection (ICSI) were analyzed. Of the 968 cycles, early-cleavage embryos were used in 432 cycles (early-cleavage group), late-cleavage embryos were used in 246 cycles (late-cleavage group), and both early and late-cleavage embryos were used in 290 cycles (mixed group).
  
  
  RESULTS
  High-quality embryo rate was significantly higher in early-cleavage group than in late-cleavage group (82.74% vs 59.83%; p < 0.01). Both clinical pregnancy and implantation rates in IVF or ICSI were significantly higher in early-cleavage group than in late-cleavage group (all p < 0.01). In ICSI, both clinical pregnancy and implantation rates were significantly higher in mixed group than in late-cleavage group (all p < 0.05).
  
  
  CONCLUSIONS
  Early-cleavage ET can improve pregnancy outcomes in IVF or ICSI.
authors.affiliation: Reproductive Medical Center, First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
authors.forename: W L
authors.initials: WL
authors.lastname: Lian
authors.forename: Z M
authors.initials: ZM
authors.lastname: Xin
authors.forename: H X
authors.initials: HX
authors.lastname: Jin
authors.forename: W Y
authors.initials: WY
authors.lastname: Song
authors.forename: Z F
authors.initials: ZF
authors.lastname: Peng
authors.forename: Y P
authors.initials: YP
authors.lastname: Sun
mesh_terms: D000328:Adult; D004624:Embryo Transfer / Q000379:methods*; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D008297:Male; D011247:Pregnancy; D011256:Pregnancy Outcome; D012189:Retrospective Studies; D020554:Sperm Injections, Intracytoplasmic