title: Diabetic family history is an isolated risk factor for gestational diabetes after 30 years of age.
abstract: BACKGROUND
  Family history of diabetes is regarded as a risk factor for gestational glucose intolerance. Most selective screening policy includes family history as an indication of oral glucose tolerance test. However, few studies had evaluated the actual incidence of glucose intolerance in this group of women.
  
  
  METHODS
  Pregnant women with oral glucose tolerance test performed for family history of diabetes over two consecutive years were identified. Receiver operating curve was used to identify the age cut-off that give the highest sensitivity and specificity. The incidence of glucose intolerance was compared between women with age above and below this cut-off.
  
  
  RESULTS
  One hundred and eighty-seven women were identified. The age cut-off selected was 30.5 years. In young women (age <or= 30 years) with family history alone, the incidence of glucose intolerance is similar to that in the low risk pregnant population (12.5% and 6.3% for 8.0 mmol/L and 9.0 mmol/L cut-off for two hour value of 75 g oral glucose tolerance test, respectively). In women aged above 30 years, the incidence of glucose intolerance raised by three fold (35.2% and 22.0% for 8.0 mmol/L and 9.0 mmol/L cut-off, respectively).
  
  
  CONCLUSIONS
  The risk of glucose intolerance in young women with positive family history is similar to that in the background pregnant population. Standard oral glucose tolerance test may not be necessary in this group of women if selective screening policy is adopted.
authors.affiliation: Department of Obstetrics and Gynaecology, Princess Margaret Hosptial, Princess Margaret Hospital Road, Lai Chi Kok, Kowloon, Hong Kong, China. lyschan@netvigator.com
authors.forename: Louis Yik-Si
authors.initials: LY
authors.lastname: Chan
authors.forename: Shell Fean
authors.initials: SF
authors.lastname: Wong
authors.forename: Lau Cheung
authors.initials: LC
authors.lastname: Ho
mesh_terms: D002681:China / Q000453:epidemiology; D015331:Cohort Studies; D003920:Diabetes Mellitus / Q000453:epidemiology / Q000235:genetics*; D016640:Diabetes, Gestational / Q000453:epidemiology* / Q000209:etiology*; D005260:Female; D020022:Genetic Predisposition to Disease; D018149:Glucose Intolerance / Q000175:diagnosis / Q000453:epidemiology*; D005951:Glucose Tolerance Test; D006801:Humans; D015994:Incidence; D008423:Maternal Age; D010375:Pedigree; D011247:Pregnancy; D018570:Risk Assessment; D012307:Risk Factors