title: Live birth sex ratios are not influenced by blastocyst-stage embryo transfer.
abstract: OBJECTIVE
  To analyze the sex ratio of infants born after blastocyst-stage transfer of embryos with normal preimplantation FISH genetic screening.
  
  
  METHODS
  Retrospective cohort analysis.
  
  
  METHODS
  Large academic assisted reproductive technology center.
  
  
  METHODS
  Two hundred twenty-eight patients undergoing fresh IVF cycle with blastocyst transfer.
  
  
  METHODS
  Preimplantation genetic screening for sex complement.
  
  
  METHODS
  Sex ratio in liveborn infants following blastocyst transfer.
  
  
  RESULTS
  One thousand thirteen embryos were normal by preimplantation genetic screening of chromosomes 13, 15, 16, 17, 18, 21, 22, X, and Y. Four hundred ninety-eight normal embryos were transferred to 228 patients with an overall live birth rate of 41.7%. Transferred blastocysts were selected based upon morphologic assessment. When controlling for the sex of the blastocyst embryo, there was no difference in the male-to-female delivery rate per embryo transferred (27.3% vs. 21.4%) (relative risk =1.28, confidence interval 0.93-1.74). Of the live births 51.7% were male and 48.3% were female (P=.61). Subanalysis revealed no difference in male-to-female delivery rates in groups with a 1:1 ratio of male:female embryos transferred, a non 1:1 ratio transferred, or single-sex transfers.
  
  
  CONCLUSIONS
  Blastocyst-stage embryo transfer does not influence the live birth sex ratio of embryos with normal preimplantation FISH genetic screening.
authors.affiliation: National Institutes of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland.
authors.forename: John M
authors.initials: JM
authors.lastname: Csokmay
authors.affiliation: Blanchfield Army Community Hospital, Ft. Campbell, Kentucky.
authors.forename: Micah J
authors.initials: MJ
authors.lastname: Hill
authors.affiliation: Reproductive Medicine Associates of New Jersey, Morristown, New Jersey.
authors.forename: Frank V
authors.initials: FV
authors.lastname: Cioppettini
authors.affiliation: Reproductive Medicine Associates of New Jersey, Morristown, New Jersey.
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Miller
authors.affiliation: Reproductive Medicine Associates of New Jersey, Morristown, New Jersey.
authors.forename: Richard T
authors.initials: RT
authors.lastname: Scott
authors.affiliation: Reproductive Medicine Associates of New Jersey, Morristown, New Jersey. Electronic address: jfrattarelli@rmanj.com.
authors.forename: John L
authors.initials: JL
authors.lastname: Frattarelli
mesh_terms: D000328:Adult; D001755:Blastocyst / Q000166:cytology*; D015331:Cohort Studies; D004624:Embryo Transfer / Q000379:methods*; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods; D005820:Genetic Testing; D006801:Humans; D050498:Live Birth; D008297:Male; D011247:Pregnancy; D011256:Pregnancy Outcome; D018873:Pregnancy Rate; D012189:Retrospective Studies; D012744:Sex Ratio