title: Maternal factors and the risk of birth defects after IVF and ICSI: a whole of population cohort study.
abstract: OBJECTIVE
  To assess the contribution of maternal factors to major birth defects after in vitro fertilisation (IVF), intracytoplasmic sperm injection (ICSI), and natural conception.
  
  
  METHODS
  Retrospective cohort study in South Australia for the period January 1986 to December 2002.
  
  
  METHODS
  A whole of population study.
  
  
  METHODS
  A census of all IVF and ICSI linked to registries for births, pregnancy terminations, and birth defects (diagnosed before a child's fifth birthday).
  
  
  METHODS
  Odds ratios (ORs) for birth defects were calculated among IVF, ICSI, and natural conceptions for maternal age, parity, pre-pregnancy BMI, smoking, pre-existing diseases, and conditions in pregnancy, with adjustment for confounding factors.
  
  
  METHODS
  Birth defects classified by International Classification of Diseases (ninth revision) and British Paediatric Association (ICD9-BPA) codes.
  
  
  RESULTS
  There were 2211 IVF, 1399 ICSI, and 301 060 naturally conceived births. The unadjusted prevalence of any birth defect was 7.1, 9.9, and 5.7% in the IVF, ICSI, and natural conception groups, respectively. As expected, the risk of birth defects increased with maternal age among the natural conceptions. In contrast, for IVF and ICSI combined, relative to natural conceptions, births to women aged ≤29 years had a higher risk (adjusted odds ratio, aOR 1.42; 95% confidence interval, 95% CI 1.04-1.94), births to women aged 35-39 years had no difference in risk (aOR 1.01; 95% CI 0.74-1.37), and births to women aged ≥40 years had a lower risk of defects (aOR 0.45; 95% CI 0.22-0.92). Defects were also elevated for nulliparity, anaemia, and urinary tract infection in births after ICSI, but not after IVF.
  
  
  CONCLUSIONS
  The usual age-birth defect relationship is reversed in births after IVF and ICSI, and the associations for other maternal factors and defects vary between IVF and ICSI.
  
  
  CONCLUSIONS
  Risk of birth defects in women over 40 years is lower after infertility treatment than for natural conceptions.
authors.affiliation: Robinson Research Institute, The University of Adelaide, Adelaide, SA, Australia.
authors.forename: M J
authors.initials: MJ
authors.lastname: Davies
authors.affiliation: Robinson Research Institute, The University of Adelaide, Adelaide, SA, Australia.
authors.forename: A R
authors.initials: AR
authors.lastname: Rumbold
authors.affiliation: Department of Obstetrics and Gynaecology, Royal Women's Hospital, The University of Melbourne, Parkville, Vic., Australia.
authors.forename: J L
authors.initials: JL
authors.lastname: Marino
authors.affiliation: School of Public Health, The University of Adelaide, Adelaide, SA, Australia.
authors.forename: K
authors.initials: K
authors.lastname: Willson
authors.affiliation: Robinson Research Institute, The University of Adelaide, Adelaide, SA, Australia.|School of Public Health, The University of Adelaide, Adelaide, SA, Australia.
authors.forename: L C
authors.initials: LC
authors.lastname: Giles
authors.affiliation: Robinson Research Institute, The University of Adelaide, Adelaide, SA, Australia.|School of Public Health, The University of Adelaide, Adelaide, SA, Australia.
authors.forename: M J
authors.initials: MJ
authors.lastname: Whitrow
authors.affiliation: Pregnancy Outcome Unit, SA Health, Government of South Australia, Adelaide, SA, Australia.
authors.forename: W
authors.initials: W
authors.lastname: Scheil
authors.affiliation: School of Public Health and Preventive Medicine Monash University, Melbourne, Vic., Australia.
authors.forename: L J
authors.initials: LJ
authors.lastname: Moran
authors.affiliation: Robinson Research Institute, The University of Adelaide, Adelaide, SA, Australia.
authors.forename: J G
authors.initials: JG
authors.lastname: Thompson
authors.affiliation: Robinson Research Institute, The University of Adelaide, Adelaide, SA, Australia.
authors.forename: M
authors.initials: M
authors.lastname: Lane
authors.affiliation: Robinson Research Institute, The University of Adelaide, Adelaide, SA, Australia.|School of Public Health, The University of Adelaide, Adelaide, SA, Australia.
authors.forename: V M
authors.initials: VM
authors.lastname: Moore
mesh_terms: D000328:Adult; D000013:Congenital Abnormalities / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D005306:Fertilization; D005307:Fertilization in Vitro / Q000009:adverse effects*; D006801:Humans; D007231:Infant, Newborn; D008423:Maternal Age; D016017:Odds Ratio; D010298:Parity; D011247:Pregnancy; D015995:Prevalence; D012042:Registries; D012189:Retrospective Studies; D012307:Risk Factors; D013021:South Australia / Q000453:epidemiology; D020554:Sperm Injections, Intracytoplasmic / Q000009:adverse effects*; D055815:Young Adult
keywords: Birth defects; ICSI; IVF; Infertility; maternal factors