title: Use of the egg-share model to investigate the paternal influence on fertilization and embryo development after in vitro fertilization and intracytoplasmic sperm injection.
abstract: OBJECTIVE
  To investigate whether sperm from different males can influence fertilization and embryo development.
  
  
  METHODS
  To use an egg-sharing model, in which the eggs from one woman are shared between herself and a recipient, and different spermatozoa are used to fertilize the eggs.
  
  
  METHODS
  Assisted Conception Unit, Birmingham Women's Hospital, Edgbaston, United Kingdom.
  
  
  METHODS
  Infertile women undergoing egg sharing.
  
  
  METHODS
  In vitro fertilization (IVF).
  
  
  METHODS
  Fertilization rates and the mean day 2 or 3 embryo score (cell number X grade) were examined for egg-sharing pairs. A comparison was also made for pairs in which intracytoplasmic sperm injection (ICSI) and IVF was used as the insemination method. A paired samples t-test was used to compare the sharer and recipient results.
  
  
  RESULTS
  Pregnancy rates did not differ between sharer and recipient couples. Interestingly, when comparing fertilization, there was a significant difference (P<.05) in favor of IVF over ICSI. When comparing embryo development between egg-sharing pairs, we found that approximately 30% of patients showed a difference in mean embryo score of >or= 5 in all embryo development and 14% in the quality of embryos available for transfer.
  
  
  CONCLUSIONS
  We showed that the egg-sharing model is a successful alternative for the treatment of women who required donated eggs. More important, the egg-sharing model shows that, in a certain percentage of couples, differences in early embryo development are paternally influenced.
authors.affiliation: Department of Obstetrics and Gynecology, Yale University School of Medicine, New Haven, Connecticut 06520-8063, USA. denny.sakkas@yale.edu
authors.forename: Denny
authors.initials: D
authors.lastname: Sakkas
authors.forename: Yvonne
authors.initials: Y
authors.lastname: D'Arcy
authors.forename: Gail
authors.initials: G
authors.lastname: Percival
authors.forename: Lucinda
authors.initials: L
authors.lastname: Sinclair
authors.forename: Masoud
authors.initials: M
authors.lastname: Afnan
authors.forename: Khaldoun
authors.initials: K
authors.lastname: Sharif
mesh_terms: D004622:Embryo, Mammalian / Q000502:physiology; D005314:Embryonic and Fetal Development / Q000502:physiology*; D005260:Female; D005306:Fertilization / Q000502:physiology*; D005307:Fertilization in Vitro; D006801:Humans; D008297:Male; D018587:Oocyte Donation; D020554:Sperm Injections, Intracytoplasmic; D013094:Spermatozoa / Q000502:physiology*