title: Successful pregnancy resulting from cryopreserved pronuclear and cleaved embryos thawed and cultured to blastocysts, refrozen and transferred. A case report.
abstract: BACKGROUND
  Twice-frozen, thawed embryos may have utilization in vitro fertilization (IVF) cycles.
  
  
  METHODS
  A 37-year-old woman with endometriosis and infertility returned five years after a fresh IVF cycle. Seven cryopreserved embryos (2 pronuclear [pn] and cleaved) were thawed, and five developed to the blastocyst stage. One blastocyst was transferred, and the remaining four were recryopreserved. This transfer did not result in pregnancy. The remaining four blastocysts were thawed, and two were transferred resulting in a live, singleton delivery.
  
  
  CONCLUSIONS
  Pregnancy can result from cryopreserved 2-pn and cleaved embryos cultured to blastocysts, refrozen and then transferred at the blastocyst stage.
authors.affiliation: Toll Center for Reproductive Sciences, Department of Obstetrics and Gynecology, Abington Hospital, Abington, Pennsylvania, USA.
authors.forename: Stephanie J
authors.initials: SJ
authors.lastname: Estes
authors.forename: Donna C
authors.initials: DC
authors.lastname: Laky
authors.forename: Linda M
authors.initials: LM
authors.lastname: Hoover
authors.forename: Scott E
authors.initials: SE
authors.lastname: Smith
authors.forename: Jay S
authors.initials: JS
authors.lastname: Schinfeld
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Somkuti
mesh_terms: D000328:Adult; D001755:Blastocyst; D015925:Cryopreservation / Q000379:methods*; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods; D006801:Humans; D007247:Infertility, Female; D011247:Pregnancy; D011256:Pregnancy Outcome; D018570:Risk Assessment