title: Birth after double cryopreservation of human oocytes at metaphase II and pronuclear stages.
abstract: OBJECTIVE
  To document the possibility to double-cryopreserve human metaphase II and pronuclear oocytes.
  
  
  METHODS
  Case report.
  
  
  METHODS
  University-based IVF center.
  
  
  METHODS
  A couple with primary andrological infertility.
  
  
  METHODS
  Pronuclear stage oocytes derived after sperm injection into frozen-thawed metaphase II oocytes were cryopreserved again for later transfer.
  
  
  METHODS
  Post-thaw survival rates and pregnancy.
  
  
  RESULTS
  Five metaphase II oocytes survived the freeze-thaw procedure. Three of five oocytes presented with two pronuclei after sperm injection and were cryopreserved again. Post-thawing, all three oocytes developed into good quality embryos for transfer. A singleton pregnancy was achieved, resulting in the birth of a healthy girl.
  
  
  CONCLUSIONS
  Double-cryopreservation of oocytes at metaphase II and at pronuclear stage is a treatment option in human-assisted reproduction.
authors.affiliation: Department of Gynecological Endocrinology and Reproductive Medicine, University of Bonn, Bonn, Germany. Markus.Montag@ukb.uni-bonn.de
authors.forename: Markus
authors.initials: M
authors.lastname: Montag
authors.forename: Katrin
authors.initials: K
authors.lastname: van der Ven
authors.forename: Christoph
authors.initials: C
authors.lastname: Dorn
authors.forename: Vladimir
authors.initials: V
authors.lastname: Isachenko
authors.forename: Eugenia
authors.initials: E
authors.lastname: Isachenko
authors.forename: Hans
authors.initials: H
authors.lastname: van der Ven
mesh_terms: D000328:Adult; D015925:Cryopreservation; D004624:Embryo Transfer; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008677:Metaphase; D009865:Oocytes / Q000166:cytology*; D036801:Parturition; D011247:Pregnancy; D011418:Prophase; D020554:Sperm Injections, Intracytoplasmic