title: Culture of human spare preembryos: association between blastocyst formation and pregnancy.
abstract: The rate of blastocyst development was studied in cultures of human fertilized eggs. A total of 195 spare embryos from 86 cycles in 73 in vitro fertilization (IVF) patients resulted in a total of 77 expanded blastocysts, corresponding to an overall blastocyst development of 39%. In the group of patients where pregnancy occurred, at least one of the spare embryos developed into the blastocyst stage in 100% of the patients, while the corresponding figure for nonpregnant patients was 53%. Superficially these results seem to indicate that blastocyst development could be of decisive importance for the success rate in IVF. A detailed analysis revealed, however, that this is not the case as long as in vitro culture before replacement is limited to 2-3 days.
authors.affiliation: Department of Obstetrics and Gynaecology, University of Göteborg, Sahlgrenska University Hospital, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Sjögren
authors.forename: P
authors.initials: P
authors.lastname: Sjöblom
authors.forename: L
authors.initials: L
authors.lastname: Hamberger
mesh_terms: D000328:Adult; D001755:Blastocyst; D046508:Culture Techniques; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D007246:Infertility / Q000628:therapy*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016896:Treatment Outcome