title: Increased incidence of glucose disorders during pregnancy is not explained by pre-pregnancy obesity in London, Canada.
abstract: BACKGROUND
  The increasing incidence of impaired glucose tolerance (IGT), gestational diabetes (GDM) and type 2 diabetes (T2D) during pregnancy was hypothesized to be associated with increases in pre-pregnancy body mass index (BMI). The aims were to 1) determine the prevalence of IGT/GDM/T2 D over a 10 year period; 2) examine the relationship between maternal overweight/obesity and IGT/GDM/T2D; and 3) examine the extent to which maternal metabolic complications impact maternal and fetal pregnancy outcomes.
  
  
  METHODS
  Data arose from a perinatal database which contains maternal characteristics and perinatal outcome for all singleton infants born in London, Canada between January 1, 2000 and December 31, 2009. Univariable and multivariable odds ratios (OR) were estimated using logistic regression with IGT/GDM/T2 D being the outcome of interest.
  
  
  RESULTS
  A total of 36,597 women were included in the analyses. Population incidence of IGT, GDM and T2 D rose from 0.7%, 2.9% and 0.5% in 2000 to 1.2%, 4.2% and 0.9% in 2009. The univariable OR for IGT, GDM and T2 D were 1.65, 1.52 and 2.06, respectively, over the ten year period. After controlling for maternal age, parity and pre-pregnancy BMI the OR did not decrease. Although there was a positive relationship between pre-pregnancy BMI and prevalence of IGT/GDM/T2 D, this did not explain the time trends in the latter. Diagnosis of IGT/GDM/T2 D increased the risk of having an Apgar score <7 at 5 minutes, which was partially explained by gestational hypertension, high placental ratio, gestational age and large for gestational age babies.
  
  
  CONCLUSIONS
  We found a significant increase in the incidence of IGT/GDM/T2 D for the decade between 2000-2009 which was not explained by rising prevalence of maternal overweight/obesity.
authors.affiliation: R, Samuel McLaughlin Foundation Exercise and Pregnancy Lab, School of Kinesiology, The University of Western Ontario, London, Ontario, N6A 3K7, Canada.
authors.forename: Margie H
authors.initials: MH
authors.lastname: Davenport
authors.forename: M Karen
authors.initials: MK
authors.lastname: Campbell
authors.forename: Michelle F
authors.initials: MF
authors.lastname: Mottola
mesh_terms: D000293:Adolescent; D000328:Adult; D015992:Body Mass Index; D002170:Canada / Q000453:epidemiology; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology* / Q000209:etiology; D016640:Diabetes, Gestational / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D018149:Glucose Intolerance / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology*; D016017:Odds Ratio; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology* / Q000209:etiology; D015995:Prevalence; D013997:Time Factors; D055815:Young Adult