title: Population-based study of cesarean section after in vitro fertilization in Australia.
abstract: BACKGROUND
  Decisions about method of birth should be evidence based. In Australia, the rising rate of cesarean section has not been limited to births after spontaneous conception. This study aimed to investigate cesarean section among women giving birth after in vitro fertilization (IVF).
  
  
  METHODS
  Retrospective population-based study was conducted using national registry data on IVF treatment. The study included 17,019 women who underwent IVF treatment during 2003 to 2005 and a national comparison population of women who gave birth in Australia. The outcome measure was cesarean section.
  
  
  RESULTS
  Crude rate of cesarean section was 50.1 percent versus 28.9 percent for all other births. Single embryo transfer was associated with the lowest (40.7%) rate of cesarean section. Donor status and twin gestation were associated with significantly higher rates of cesarean section (autologous, 49.0% vs donor, 74.9%; AOR: 2.20, 95% CI: 1.80, 2.69) and (singleton, 45.0% vs twin gestations, 75.7%; AOR: 3.81, 95% CI: 3.46, 4.20). The gestation-specific rate (60.1%) of cesarean section peaked at 38 weeks for singleton term pregnancies. Compared with other women, cesarean section rates for assisted reproductive technology term singletons (27.8% vs 43.8%, OR: 2.02 [95% CI: 1.95-2.10]) and twins (62.0% vs 75.7%, OR: 1.92 [95% CI: 1.74-2.11]) were significantly higher.
  
  
  CONCLUSIONS
  Rates for cesarean section appear to be disproportionately high in term singleton births after assisted reproductive technology. Vaginal birth should be supported and the indications for cesarean section evidence based.
authors.affiliation: Perinatal and Reproductive Epidemiology Research Unit, School of Women's and Children's Health, University of New South Wales, Sydney, Australia.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Sullivan
authors.forename: Michael G
authors.initials: MG
authors.lastname: Chapman
authors.forename: Yueping A
authors.initials: YA
authors.lastname: Wang
authors.forename: G David
authors.initials: GD
authors.lastname: Adamson
mesh_terms: D000328:Adult; D001315:Australia; D002585:Cesarean Section / Q000706:statistics & numerical data*; D055317:Evidence-Based Practice; D005260:Female; D005306:Fertilization; D005307:Fertilization in Vitro / Q000706:statistics & numerical data*; D006801:Humans; D008875:Middle Aged; D009321:Natural Childbirth / Q000706:statistics & numerical data; D018587:Oocyte Donation / Q000706:statistics & numerical data; D011247:Pregnancy; D012042:Registries; D012044:Regression Analysis; D012189:Retrospective Studies; D014427:Twins