title: Comparable implantation rates with fresh vs frozen embryo transfer suggests that controlled ovarian hyperstimulation has an adverse effect on conception outcome.
abstract: OBJECTIVE
  A retrospective comparison of fresh vs frozen embryo pregnancy rates.
  
  
  METHODS
  All frozen embryos transferred used in the analysis including deselected embryos from the oocyte retrieval cycle, and twice-frozen embryos.
  
  
  RESULTS
  Pregnancy and implantation rates following fresh or frozen embryo transfers were similar.
  
  
  CONCLUSIONS
  The similar outcomes despite the obvious disadvantages for the frozen-thawed embryo suggests that some other factor reduces the chance of embryo implantation on oocyte-retrieval cycles. An adverse affect of controlled ovarian hyperstimulation on the uterine environment is a strong possibility.
authors.affiliation: The University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School at Camden Cooper Hospital/University Medical Center, Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology & Infertility, USA.
authors.forename: J H
authors.initials: JH
authors.lastname: Check
authors.forename: D
authors.initials: D
authors.lastname: Katsoff
authors.forename: D
authors.initials: D
authors.lastname: Brittingham
authors.forename: D
authors.initials: D
authors.lastname: Summers-Chase
authors.forename: C
authors.initials: C
authors.lastname: Wilson
mesh_terms: D000328:Adult; D000375:Aging; D015925:Cryopreservation; D010064:Embryo Implantation; D004624:Embryo Transfer; D005260:Female; D006801:Humans; D010062:Ovulation Induction / Q000009:adverse effects*; D011247:Pregnancy; D012189:Retrospective Studies