title: Preterm delivery in IVF versus ICSI singleton pregnancies: a national population-based cohort.
abstract: OBJECTIVE
  To assess the risk of spontaneous and iatrogenic preterm delivery in singleton pregnancies when comparing in vitro fertilization (IVF) pregnancies with intracytoplasmic sperm injection (ICSI) pregnancies.
  
  
  METHODS
  A national population-based cohort study using Norwegian Medical Birth Register data during 1999 through 2006 was designed. The cohort included 5824 singleton pregnancies after IVF and ICSI treatment. Multinomial logistic regression analyses were used to calculate risk estimates.
  
  
  RESULTS
  There were no differences in maternal complicating factors such as pre-eclampsia, hypertension and diabetes between the IVF and ICSI pregnancies. However, IVF pregnancies had a 60% increased risk of moderately (32(+)(0)(days)-36(+)(6)(days) gestational weeks) iatrogenic preterm delivery (OR: 1.6, 95%CI: 1.1-2.2) and a 40% increased risk of iatrogenic preterm delivery <37 weeks (OR: 1.4, 95%CI: 1.02-1.9) compared to ICSI pregnancies.
  
  
  CONCLUSIONS
  IVF pregnancies were at increased risk of moderately iatrogenic preterm delivery when compared to ICSI pregnancies.
authors.affiliation: Department of Obstetrics and Gynecology, Haukeland University Hospital, 5021 Bergen, Norway. nhmorken@online.no
authors.forename: Nils-Halvdan
authors.initials: NH
authors.lastname: Morken
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D005307:Fertilization in Vitro / Q000009:adverse effects; D006801:Humans; D007049:Iatrogenic Disease / Q000453:epidemiology; D007231:Infant, Newborn; D007234:Infant, Premature; D007751:Labor, Induced; D008423:Maternal Age; D009664:Norway / Q000453:epidemiology; D011247:Pregnancy; D047928:Premature Birth / Q000453:epidemiology / Q000209:etiology*; D020554:Sperm Injections, Intracytoplasmic / Q000009:adverse effects