title: Elective single embryo transfer: Is frozen better than fresh?
abstract: OBJECTIVE
  Single embryo transfer (SET) has been recommended to avoid multiple births following assisted reproductive technology (ART) procedures. Many studies have shown that frozen embryo transfer may yield better pregnancy rates than fresh embryo transfer. This study looked into pregnancy rates following fresh versus frozen single embryo transfer procedures in age-matched patients.
  
  
  METHODS
  This retrospective case control study was carried out at a private clinic [NewLife Fertility Clinic, ON, Canada]. Patient groups included infertile women treated with IVF/ICSI and elective single embryo transfer (eSET) given either fresh or frozen embryos. Cycle outcomes were compared between patient groups matched by age. The primary endpoints were positive testing for ß-hCG and viable ongoing pregnancy. The secondary endpoints were live birth and miscarriage rates.
  
  
  RESULTS
  A total of 583 eSET cycles (212 fresh transfer cycles and 371 frozen transfer cycles) were performed. Significantly higher pregnancy and live birth rates were observed among patients aged ≤ 39 years given frozen embryos.
  
  
  CONCLUSIONS
  Frozen single embryo transfer was associated with higher pregnancy and live birth rates when compared to fresh single embryo transfer.
authors.affiliation: NewLife Fertility Center, Mississauga, Ontario, Canada.
authors.forename: Hala
authors.initials: H
authors.lastname: Gomaa
authors.affiliation: NewLife Fertility Center, Mississauga, Ontario, Canada.
authors.forename: Rania
authors.initials: R
authors.lastname: Baydoun
authors.affiliation: NewLife Fertility Center, Mississauga, Ontario, Canada.
authors.forename: Sakina
authors.initials: S
authors.lastname: Sachak
authors.affiliation: NewLife Fertility Center, Mississauga, Ontario, Canada.
authors.forename: Ilyn
authors.initials: I
authors.lastname: Lapana
authors.affiliation: NewLife Fertility Center, Mississauga, Ontario, Canada.
authors.forename: Samuel
authors.initials: S
authors.lastname: Soliman
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D015925:Cryopreservation; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D011247:Pregnancy; D012189:Retrospective Studies; D056826:Single Embryo Transfer / Q000379:methods* / Q000706:statistics & numerical data*
keywords: Fresh embryo transfer; Frozen embryo transfer; IVF; Pregnancy rate; eSET