title: Impact of pre-pregnancy diabetes mellitus on congenital anomalies, Canada, 2002-2012.
abstract: OBJECTIVE
  To examine the impact of pre-pregnancy diabetes mellitus (DM) on the population birth prevalence of congenital anomalies in Canada.
  
  
  METHODS
  We carried out a population-based study of all women who delivered in Canadian hospitals (except those in the province of Quebec) between April 2002 and March 2013 and their live-born infants with a birth weight of 500 grams or more and/or a gestational age of 22 weeks or more. Pre-pregnancy type 1 or type 2 DM was identified using ICD-10 diagnostic codes. The association between DM and all congenital anomalies as well as specific congenital anomaly categories was estimated using adjusted odds ratios; the impact was calculated as a population attributable risk percent (PAR%).
  
  
  RESULTS
  There were 118,892 infants with a congenital anomaly among 2,839,680 live births (41.9 per 1000). While the prevalence of any congenital anomaly declined from 50.7 per 1000 live births in 2002/03 to 41.5 per 1000 in 2012/13, the corresponding PAR% for a congenital anomaly related to pre-pregnancy DM rose from 0.6% (95% confidence interval [CI]: 0.4-0.8) to 1.2% (95% CI: 0.9-1.4). Specifically, the PAR% for congenital cardiovascular defects increased from 2.3% (95% CI: 1.7-2.9) to 4.2% (95% CI: 3.5-4.9) and for gastrointestinal defects from 0.8% (95% CI: 0.2-1.9) to 1.4% (95% CI: 0.7-2.6) over the study period.
  
  
  CONCLUSIONS
  Although there has been a relative decline in the prevalence of congenital anomalies in Canada, the proportion of congenital anomalies due to maternal pre-pregnancy DM has increased. Enhancement of preconception care initiatives for women with DM is recommended.
authors.affiliation: Maternal, Child & Youth Health Unit, Surveillance and Epidemiology Division, Centre for Chronic Disease Prevention, Public Health Agency of Canada, Ottawa, Ontario, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Liu
authors.affiliation: Maternal, Child & Youth Health Unit, Surveillance and Epidemiology Division, Centre for Chronic Disease Prevention, Public Health Agency of Canada, Ottawa, Ontario, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Rouleau
authors.affiliation: Maternal, Child & Youth Health Unit, Surveillance and Epidemiology Division, Centre for Chronic Disease Prevention, Public Health Agency of Canada, Ottawa, Ontario, Canada.
authors.forename: J A
authors.initials: JA
authors.lastname: León
authors.affiliation: Departments of Pediatrics and Community Health Sciences, University of Calgary, Calgary, Alberta, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Sauve
authors.affiliation: Department of Obstetrics & Gynaecology, University of British Columbia, Vancouver, British Columbia, Canada.|Children's and Women's Hospital of British Columbia, Vancouver, British Columbia, Canada.|School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: K S
authors.initials: KS
authors.lastname: Joseph
authors.affiliation: Departments of Medicine, Health Policy Management and Evaluation, and Obstetrics and Gynecology, St Michael's Hospital, University of Toronto, Toronto, Ontario, Canada.
authors.forename: J G
authors.initials: JG
authors.lastname: Ray
mesh_terms: D000328:Adult; D002170:Canada / Q000453:epidemiology; D000013:Congenital Abnormalities / Q000453:epidemiology* / Q000209:etiology; D003922:Diabetes Mellitus, Type 1 / Q000150:complications / Q000453:epidemiology*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000453:epidemiology*; D004065:Digestive System Abnormalities / Q000453:epidemiology; D005260:Female; D006330:Heart Defects, Congenital / Q000453:epidemiology; D006801:Humans; D007231:Infant, Newborn; D050498:Live Birth / Q000453:epidemiology; D009139:Musculoskeletal Abnormalities / Q000453:epidemiology; D009421:Nervous System Malformations / Q000453:epidemiology; D011247:Pregnancy; D011254:Pregnancy in Diabetics / Q000453:epidemiology*; D015995:Prevalence; D012307:Risk Factors; D014564:Urogenital Abnormalities / Q000453:epidemiology
keywords: birth defect; congenital anomaly; diabetes mellitus; population attributable risk percent; pre-pregnancy; trends