title: Comparison of pregnancy outcomes in elective single blastocyst transfer versus double blastocyst transfer stratified by age.
abstract: OBJECTIVE
  To determine whether there is a difference in pregnancy outcomes, stratified by age, between women undergoing elective single blastocyst transfer (eSBT) versus those undergoing double blastocyst transfer (2BT).
  
  
  METHODS
  Retrospective analysis.
  
  
  METHODS
  University IVF center.
  
  
  METHODS
  A total of 1,141 nondonor IVF cycles in women aged <40 years from January 2004-March 2007.
  
  
  METHODS
  None.
  
  
  METHODS
  Eggs retrieved, embryos cryopreserved, implantation rates, clinical pregnancy rates (PR), live birth rates (LBR), spontaneous abortion rates (SAB).
  
  
  RESULTS
  Pregnancy outcomes in 52 cycles of women <40 years of age who underwent eSBT were compared with 1,086 cycles of women who underwent 2BT in fresh IVF cycles from January 2004-March 2007. Overall, the eSBT was associated with a statistically significant 92% reduction in the twinning rate (from 25%-2%) while maintaining a high clinical PR (63% in the eSBT group vs. 61% in the 2BT group).
  
  
  CONCLUSIONS
  Women who are <40 years of age undergoing nondonor fresh IVF cycles can electively choose to transfer a single blastocyst for the purpose of significantly reducing their risk of multiples without compromising their PR.
authors.affiliation: New York University Fertility Center, New York University, New York, New York 10016, USA. christine.mullin@gmail.com
authors.forename: Christine M
authors.initials: CM
authors.lastname: Mullin
authors.forename: M Elizabeth
authors.initials: ME
authors.lastname: Fino
authors.forename: Sheeva
authors.initials: S
authors.lastname: Talebian
authors.forename: Lewis C
authors.initials: LC
authors.lastname: Krey
authors.forename: Frederick
authors.initials: F
authors.lastname: Licciardi
authors.forename: Jamie A
authors.initials: JA
authors.lastname: Grifo
mesh_terms: D000328:Adult; D000367:Age Factors; D017558:Elective Surgical Procedures; D019924:Embryo Disposition; D004624:Embryo Transfer / Q000379:methods*; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods; D006801:Humans; D007247:Infertility, Female / Q000628:therapy; D011247:Pregnancy; D011256:Pregnancy Outcome; D018873:Pregnancy Rate; D012189:Retrospective Studies; D056826:Single Embryo Transfer / Q000379:methods