title: First polar body morphology before ICSI is not related to embryo quality or pregnancy rate.
abstract: BACKGROUND
  The aim of this study was to analyse the relationship between the first polar body (1st PB) morphology and the fertilization rate, cleavage rate, embryo quality, pregnancy and implantation rate.
  
  
  METHODS
  This was a retrospective study on 167 consecutive cycles undergoing assisted reproduction with ICSI. The 1st PB morphology was evaluated at the moment of ICSI in the 596 injected oocytes and it was coded as intact or fragmented. The fertilization rate, cleavage rate, embryo quality (three grades), pregnancy rate, implantation rate and the time elapsed between oocyte retrieval and ICSI were evaluated. The 1st PB morphology was checked twice (denudation and ICSI) in a random sample of 180 oocytes in order to verify the effect of the in vitro culture.
  
  
  RESULTS
  No significant relationship was found between the 1st PB morphology and the fertilization rate (P=0.703), cleavage rate (P=0.055), embryo quality (P=0.673), pregnancy rate (P=0.201) and implantation rate (P=0.511). A significant positive relationship (P=0.006) was found between the frequency of the 1st PB fragmentation and the time elapsed between denudation and ICSI. The pregnancy rate was significantly higher (P=0.008) when oocytes were injected between 5 and 7 h after retrieval rather than earlier or later.
  
  
  CONCLUSIONS
  Our data suggest that the embryo quality, pregnancy rate and implantation rate are not related to the 1st PB fragmentation. The time which elapses between the oocyte retrieval and ICSI should be maintained at approximately 6 h in order to obtain optimal results.
authors.affiliation: Infertility and IVF Centre, Human Reproductive Medicine Unit, Alma Mater Studiorum, University of Bologna, Via Massarenti 13, 40138 Bologna, Italy. ciottip@orsola-malpighi.med.unibo.it
authors.forename: P M
authors.initials: PM
authors.lastname: Ciotti
authors.forename: L
authors.initials: L
authors.lastname: Notarangelo
authors.forename: A M
authors.initials: AM
authors.lastname: Morselli-Labate
authors.forename: V
authors.initials: V
authors.lastname: Felletti
authors.forename: E
authors.initials: E
authors.lastname: Porcu
authors.forename: S
authors.initials: S
authors.lastname: Venturoli
mesh_terms: D002970:Cleavage Stage, Ovum; D010064:Embryo Implantation; D004622:Embryo, Mammalian / Q000502:physiology*; D005260:Female; D005306:Fertilization; D006801:Humans; D008297:Male; D009865:Oocytes / Q000648:ultrastructure*; D009866:Oogenesis; D011247:Pregnancy; D018873:Pregnancy Rate; D012189:Retrospective Studies; D020554:Sperm Injections, Intracytoplasmic; D013997:Time Factors