title: In vitro fertilization (IVF) in Sweden: infant outcome after different IVF fertilization methods.
abstract: OBJECTIVE
  To compare infant outcome after different IVF techniques.
  
  
  METHODS
  A register study in Sweden of IVF infants compared with all infants born.
  
  
  METHODS
  National health registers.
  
  
  METHODS
  We studied 16,280 IVF infants, 30% of whom were conceived by intracytoplasmic sperm injection (ICSI).
  
  
  METHODS
  None.
  
  
  METHODS
  Multiple births, infant sex, preterm birth, low birth weight, and small for gestational age among singletons, mortality, low Apgar score, neonatal diagnoses.
  
  
  RESULTS
  Twinning was less frequent after frozen standard IVF (18.1%) and after ICSI (21.8%) than after fresh standard IVF (24.4%). The male/female ratio was significantly increased in infants conceived after standard IVF. No significant differences were seen between singleton infants conceived after different IVF methods with respect to preterm birth, low birth weight, or infant mortality, with the possible exception of frozen standard IVF, for which some of these rates were lower than after fresh standard IVF. Infants born after ICSI had an indicated lower risk of respiratory problems than infants born after standard IVF.
  
  
  CONCLUSIONS
  Little difference in outcome was seen after different IVF methods. The differences observed might be due to dissimilar characteristics of the treated women (e.g., because ICSI was mainly used in connection with male infertility).
authors.affiliation: Tornblad Institute, University of Lund, Lund, Sweden.
authors.forename: Bengt
authors.initials: B
authors.lastname: Källén
authors.forename: Orvar
authors.initials: O
authors.lastname: Finnström
authors.forename: Karl-Gösta
authors.initials: KG
authors.lastname: Nygren
authors.forename: Petra Otterblad
authors.initials: PO
authors.lastname: Olausson
mesh_terms: D016001:Confidence Intervals; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods* / Q000706:statistics & numerical data; D006801:Humans; D007231:Infant, Newborn; D050498:Live Birth / Q000453:epidemiology*; D008297:Male; D016017:Odds Ratio; D011247:Pregnancy; D011272:Pregnancy, Multiple / Q000706:statistics & numerical data; D013548:Sweden; D016896:Treatment Outcome