title: Frozen blastocyst embryo transfer using a supplemented natural cycle protocol has a similar live birth rate compared to a programmed cycle protocol.
abstract: OBJECTIVE
  The purpose of this study is to compare outcomes for a supplemented natural cycle with a programmed cycle protocol for frozen blastocyst transfer.
  
  
  METHODS
  A retrospective analysis was performed of frozen autologous blastocyst transfers, at a single academic fertility center (519 supplemented natural cycles and 106 programmed cycles). Implantation, clinical pregnancy, miscarriage, and live birth and birth weight were compared using Pearson's Chi-squared test, T-test, or Fisher's exact test.
  
  
  RESULTS
  There was no significant difference between natural and programmed frozen embryo transfers with respect to implantation (21.9 vs. 18.1 %), clinical pregnancy (35.5 vs. 29.2 %), and live birth rates (27.7 vs. 23.6 %). Mean birth weights were also similar between natural and programmed cycles for singletons (3354 vs. 3340 g) and twins (2422 vs. 2294 g)
  
  
  CONCLUSIONS
  Frozen blastocyst embryo transfers using supplemented natural or programmed protocols experience similar success rates. Patient preference should be considered in choosing a protocol.
authors.affiliation: Department of Obstetrics and Gynecology, Stanford University School of Medicine, Palo Alto, CA, USA, rlathi@stanford.edu.
authors.forename: Ruth B
authors.initials: RB
authors.lastname: Lathi
authors.forename: Yueh-Yun
authors.initials: YY
authors.lastname: Chi
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.forename: Briana
authors.initials: B
authors.lastname: Saravanabavanandhan
authors.forename: Aparna
authors.initials: A
authors.lastname: Hegde
authors.forename: Valerie L
authors.initials: VL
authors.lastname: Baker
mesh_terms: D000328:Adult; D001755:Blastocyst; D015925:Cryopreservation / Q000379:methods*; D010064:Embryo Implantation; D004624:Embryo Transfer / Q000379:methods*; D004958:Estradiol / Q000008:administration & dosage; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000819:agonists; D006801:Humans; D007231:Infant, Newborn; D050498:Live Birth; D011247:Pregnancy; D011256:Pregnancy Outcome; D018873:Pregnancy Rate; D011374:Progesterone / Q000008:administration & dosage
chemical_list: D007987:Gonadotropin-Releasing Hormone; D011374:Progesterone; D004958:Estradiol