title: Effect of in vitro culture of human embryos on birthweight of newborns.
abstract: BACKGROUND
  In animal models, in vitro culture of preimplantation embryos has been shown to be a risk factor for abnormal fetal outcome, including high and low birthweight. In the human, mean birthweight of singletons after in vitro fertilization (IVF) is considerably lower than after natural conception, but it is not known whether culture conditions play a role in this.
  
  
  METHODS
  We compared pregnancy rates and perinatal outcomes from singleton pregnancies resulting from a total of 826 first IVF treatment cycles in which oocytes and embryos were randomly allocated to culture in either of two commercially available sequential media systems.
  
  
  RESULTS
  When the 110 live born singletons in the Vitrolife group were compared with the 78 singletons in the Cook group, birthweight +/- SEM (3453 +/- 53 versus 3208 +/- 61 g, P = 0.003), and birthweight adjusted for gestational age and gender (mean z-score +/- SEM: 0.13 +/- 0.09 versus -0.31 +/- 0.10, P = 0.001) were both significantly higher in the Vitrolife group. When analyzed by multiple linear regression together with several other variables that could possibly affect birthweight as covariates, the type of culture medium was significantly (P = 0.01) associated with birthweight.
  
  
  CONCLUSIONS
  In vitro culture of human embryos can affect birthweight of live born singletons.
authors.affiliation: Department of Obstetrics and Gynaecology, Maastricht University Medical Centre, Center for Reproductive Medicine, Maastricht, The Netherlands. j.dumoulin@maastrichtuniversity.nl
authors.forename: John C
authors.initials: JC
authors.lastname: Dumoulin
authors.forename: Jolande A
authors.initials: JA
authors.lastname: Land
authors.forename: Aafke P
authors.initials: AP
authors.lastname: Van Montfoort
authors.forename: Ewka C
authors.initials: EC
authors.lastname: Nelissen
authors.forename: Edith
authors.initials: E
authors.lastname: Coonen
authors.forename: Josien G
authors.initials: JG
authors.lastname: Derhaag
authors.forename: Inge L
authors.initials: IL
authors.lastname: Schreurs
authors.forename: Gerard A
authors.initials: GA
authors.lastname: Dunselman
authors.forename: Arnold D
authors.initials: AD
authors.lastname: Kester
authors.forename: Joep P
authors.initials: JP
authors.lastname: Geraedts
authors.forename: Johannes L
authors.initials: JL
authors.lastname: Evers
mesh_terms: D000328:Adult; D001724:Birth Weight; D003470:Culture Media; D046149:Embryo Culture Techniques / Q000379:methods*; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007234:Infant, Premature; D007236:Infant, Small for Gestational Age; D011247:Pregnancy
chemical_list: D003470:Culture Media