title: Assisted reproductive technology and major birth defects in Western Australia.
abstract: OBJECTIVE
  To estimate the prevalence of major birth defects diagnosed by 6 years of age in all births and terminations of pregnancy for fetal anomaly conceived by assisted reproductive technology (when this included intracytoplasmic sperm injection and in vitro fertilization [IVF]) and the remainder of nonassisted reproductive technology-conceived children born in Western Australia from 1994 to 2002.
  
  
  METHODS
  This retrospective cohort study used data linkage between three population-based registers (Reproductive Technology Register, Western Australian Register of Developmental Anomalies, and Midwives' Notification of Birth System) to identify all assisted reproductive technology (n=2,911) and nonassisted reproductive technology (n=210,997) births with and without birth defects diagnosed by age 6 and all terminations of pregnancy for fetal anomaly.
  
  
  RESULTS
  A major birth defect was diagnosed in 8.7% of assisted reproductive technology and 5.4% of nonassisted reproductive technology singletons (odds ratio [OR] 1.53, 95% confidence interval [CI] 1.30-1.79), as well as 7.1% of assisted reproductive technology twins and 5.9% of nonassisted reproductive technology twins of unlike sex (OR 1.08, 95% CI 0.77-1.51). The prevalence of birth defects in assisted reproductive technology singletons and twins decreased markedly over the study period. This change was evident across all three clinics contributing data over the whole study and was particularly marked for children conceived as a result of IVF.
  
  
  CONCLUSIONS
  There has been a decrease in the prevalence of birth defects over time in children born as a result of assisted reproductive technology in Western Australia; however, the prevalence of major birth defects in assisted reproductive technology singletons remains increased compared with nonassisted reproductive technology singletons.
  
  
  METHODS
  II.
authors.affiliation: Division of Population Sciences and the Department of Biostatistics and Bioinformatics, Telethon Institute for Child Health Research and the Centre for Child Health Research, University of Western Australia, Perth, Western Australia. michele@ichr.uwa.edu.au
authors.forename: Michele
authors.initials: M
authors.lastname: Hansen
authors.forename: Jennifer J
authors.initials: JJ
authors.lastname: Kurinczuk
authors.forename: Nicholas
authors.initials: N
authors.lastname: de Klerk
authors.forename: Peter
authors.initials: P
authors.lastname: Burton
authors.forename: Carol
authors.initials: C
authors.lastname: Bower
mesh_terms: D000025:Abortion, Eugenic / Q000706:statistics & numerical data; D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D000013:Congenital Abnormalities / Q000453:epidemiology / Q000209:etiology*; D004200:Diseases in Twins / Q000453:epidemiology / Q000209:etiology; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D011247:Pregnancy; D015995:Prevalence; D012042:Registries; D027724:Reproductive Techniques, Assisted / Q000009:adverse effects*; D012189:Retrospective Studies; D014904:Western Australia / Q000453:epidemiology; D055815:Young Adult