title: The clinical significance of overt diabetes in pregnancy.
abstract: OBJECTIVE
  To explore clinical implications of overt diabetes in pregnancy on antenatal characteristics, adverse neonatal outcome and diabetes risk post-partum.
  
  
  METHODS
  Retrospective audit of prospectively collected data for all patients with gestational diabetes mellitus from 1993 to 2010. We defined overt diabetes in pregnancy as an HbA(1c) ≥ 8 mmol/mol (6.5%) or a fasting plasma glucose ≥ 7.0 mmol/l, or a 2-h glucose level ≥ 11.1 mmo/L on a 75-g oral glucose tolerance test as a surrogate for a random glucose ≥ 11.1 mmo/l.
  
  
  RESULTS
  Our audit identified 1579 women with gestational diabetes and 254 with overt diabetes in pregnancy. Women with overt diabetes in pregnancy were diagnosed earlier in pregnancy, had a higher number of risk factors for gestational diabetes, higher antenatal HbA(1c), fasting and 2-h glucose levels, higher pre-pregnancy BMI and higher insulin use and dosage requirements than those with gestational diabetes. Overt diabetes in pregnancy was associated with an increased rate of large-for-gestational-age infant, neonatal hypoglycaemia and shoulder dystocia. Of the 133 patients with overt diabetes in pregnancy who attended a follow-up oral glucose tolerance test at 6-8 weeks post-partum, 21% had diabetes, 37.6% had impaired fasting glucose or impaired glucose tolerance, whilst 41.4% returned to normal glucose tolerance.
  
  
  CONCLUSIONS
  In this patient cohort, overt diabetes in pregnancy significantly increased the risk of adverse pregnancy outcomes and post-partum impaired glucose regulation, but should not be regarded as synonymous with underlying diabetes. Two-hour glucose following a 75-g glucose load is a poor predictor of post-partum diabetes.
authors.affiliation: Department of Diabetes and Endocrinology, Bankstown-Lidcombe Hospital, Sydney, NSW, Australia.
authors.forename: T
authors.initials: T
authors.lastname: Wong
authors.forename: G P
authors.initials: GP
authors.lastname: Ross
authors.forename: B B
authors.initials: BB
authors.lastname: Jalaludin
authors.forename: J R
authors.initials: JR
authors.lastname: Flack
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D016640:Diabetes, Gestational / Q000175:diagnosis / Q000453:epidemiology*; D042241:Early Diagnosis; D005215:Fasting / Q000097:blood; D005260:Female; D018149:Glucose Intolerance; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D008485:Medical Audit; D009517:New South Wales / Q000453:epidemiology; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology*; D011254:Pregnancy in Diabetics / Q000175:diagnosis / Q000453:epidemiology*; D011296:Prenatal Diagnosis / Q000706:statistics & numerical data; D011446:Prospective Studies; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin