title: In vitro fertilization with single euploid blastocyst transfer: a randomized controlled trial.
abstract: OBJECTIVE
  To determine whether performing comprehensive chromosome screening (CCS) and transferring a single euploid blastocyst can result in an ongoing pregnancy rate that is equivalent to transferring two untested blastocysts while reducing the risk of multiple gestation.
  
  
  METHODS
  Randomized, noninferiority trial.
  
  
  METHODS
  Academic center for reproductive medicine.
  
  
  METHODS
  Infertile couples (n = 205) with a female partner less than 43 years old having a serum anti-Müllerian hormone level ≥ 1.2 ng/mL and day 3 FSH <12 IU/L.
  
  
  METHODS
  Randomization occurred when at least two blastocysts were suitable for trophectoderm biopsy. The study group (n = 89) had all viable blastocysts biopsied for real-time, polymerase chain reaction-based CCS and single euploid blastocyst transfer. The control group (n = 86) had their two best-quality, untested blastocysts transferred.
  
  
  METHODS
  The ongoing pregnancy rate to ≥ 24 weeks (primary outcome) and the multiple gestation rate.
  
  
  RESULTS
  The ongoing pregnancy rate per randomized patient after the first ET was similar between groups (60.7% after single euploid blastocyst transfer vs. 65.1% after untested two-blastocyst transfer; relative risk [RR], 0.9; 95% confidence interval [CI], 0.7-1.2). A difference of greater than 20% in favor of two-blastocyst transfer was excluded. The risk of multiple gestation was reduced after single euploid blastocyst transfer (53.4% to 0%), and patients were nearly twice as likely to have an ongoing singleton pregnancy (60.7% vs. 33.7%; RR, 1.8; 95% CI, 1.3-2.5).
  
  
  CONCLUSIONS
  In women ≤ 42 years old, transferring a single euploid blastocyst results in ongoing pregnancy rates that are the same as transferring two untested blastocysts while dramatically reducing the risk of twins.
authors.affiliation: Reproductive Medicine Associates of New Jersey, Basking Ridge, New Jersey 07920, USA. eforman@rmanj.com
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Forman
authors.forename: Kathleen H
authors.initials: KH
authors.lastname: Hong
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Ferry
authors.forename: Xin
authors.initials: X
authors.lastname: Tao
authors.forename: Deanne
authors.initials: D
authors.lastname: Taylor
authors.forename: Brynn
authors.initials: B
authors.lastname: Levy
authors.forename: Nathan R
authors.initials: NR
authors.lastname: Treff
authors.forename: Richard T
authors.initials: RT
authors.lastname: Scott
mesh_terms: D000328:Adult; D004624:Embryo Transfer / Q000379:methods*; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D006801:Humans; D007247:Infertility, Female / Q000175:diagnosis / Q000628:therapy*; D011247:Pregnancy; D018873:Pregnancy Rate / Q000639:trends*