title: Differences in pregnancy outcomes in donor egg frozen embryo transfer (FET) cycles following preimplantation genetic screening (PGS): a single center retrospective study.
abstract: OBJECTIVE
  This study aims to test the hypothesis, in a single-center retrospective analysis, that live birth rates are significantly different when utilizing preimplantation genetic screening (PGS) compared to not utilizing PGS in frozen-thawed embryo transfers in our patients that use eggs from young, anonymous donors. The question therefore arises of whether PGS is an appropriate intervention for donor egg cycles.
  
  
  METHODS
  Live birth rates per cycle and live birth rates per embryo transferred after 398 frozen embryo transfer (FET) cycles were examined from patients who elected to have PGS compared to those who did not. Blastocysts derived from donor eggs underwent trophectoderm biopsy and were tested for aneuploidy using array comparative genomic hybridization (aCGH) or next-generation sequencing (NGS), then vitrified for future use (test) or were vitrified untested (control). Embryos were subsequently warmed and transferred into a recipient or gestational carrier uterus. Data was analyzed separately for single embryo transfer (SET), double embryo transfer (DET), and for own recipient uterus and gestational carrier (GC) uterus recipients.
  
  
  RESULTS
  Rates of implantation of embryos leading to a live birth were significantly higher in the PGS groups transferring two embryos (DET) compared to the no PGS group (GC, 72 vs. 56 %; own uterus, 60 vs. 36 %). The live birth implantation rate in the own uterus group for SET was higher in the PGS group compared to the control (58 vs. 36 %), and this almost reached significance but the live birth implantation rate for the SET GC group remained the same for both tested and untested embryos. Live births per cycle were nominally higher in the PGS GC DET and own uterus SET and DET groups compared to the non-PGS embryo transfers. These differences almost reached significance. The live birth rate per cycle in the SET GC group was almost identical.
  
  
  CONCLUSIONS
  Significant differences were noted only for DET; however, benefits need to be balanced against risks associated with multiple pregnancies. Results observed for SET need to be confirmed on larger series and with randomized cohorts.
authors.affiliation: Oregon Reproductive Medicine, 808 SW 15th Ave., Portland, OR, 97205, USA.|School of Biosciences, University of Kent, Canterbury, CT2 7NJ, UK.
authors.forename: Alison
authors.initials: A
authors.lastname: Coates
authors.affiliation: Oregon Reproductive Medicine, 808 SW 15th Ave., Portland, OR, 97205, USA.
authors.forename: Brandon J
authors.initials: BJ
authors.lastname: Bankowski
authors.affiliation: School of Biosciences, University of Kent, Canterbury, CT2 7NJ, UK.|Reprogenetics, 3 Regent Street, Suite 301, Livingston, NJ, 07039, USA.
authors.forename: Allen
authors.initials: A
authors.lastname: Kung
authors.affiliation: School of Biosciences, University of Kent, Canterbury, CT2 7NJ, UK. D.K.Griffin@kent.ac.uk.
authors.forename: Darren K
authors.initials: DK
authors.lastname: Griffin
authors.affiliation: Reprogenetics, 3 Regent Street, Suite 301, Livingston, NJ, 07039, USA.
authors.forename: Santiago
authors.initials: S
authors.lastname: Munne
mesh_terms: D000328:Adult; D001755:Blastocyst / Q000166:cytology*; D055028:Comparative Genomic Hybridization; D015925:Cryopreservation; D010064:Embryo Implantation; D005260:Female; D005307:Fertilization in Vitro; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D050498:Live Birth; D011247:Pregnancy; D011256:Pregnancy Outcome; D019836:Preimplantation Diagnosis; D016032:Randomized Controlled Trials as Topic; D012189:Retrospective Studies; D056826:Single Embryo Transfer / Q000379:methods*; D058989:Vitrification
keywords: Aneuploidy; Donor egg; IVF; Preimplantation diagnosis for aneuploidy (PGS)