title: Maternal hemoglobin and risk of gestational diabetes mellitus in Chinese women.
abstract: OBJECTIVE
  To examine the relationship between high maternal hemoglobin concentration at the initial antenatal visit and occurrence of gestational diabetes mellitus (GDM) in the third trimester in nonanemic women.
  
  
  METHODS
  In a prospective observational study, 762 nondiabetic Chinese women with singleton pregnancies, whose initial visit hemoglobin concentration and mean cell volume were 10 g/dL or more and 80 fL or more, respectively, recruited at 28-30 weeks, had blood drawn for repeat measurement of hemoglobin concentration and iron parameters. These women were categorized by their initial visit hemoglobin concentration into quartiles, and the incidence of GDM was analyzed together with the maternal characteristics and iron status.
  
  
  RESULTS
  The final study sample comprised 730 women. Compared with the rest, the group in the highest hemoglobin quartile (more than 13 g/dL) had a significantly higher incidence of GDM (18.7% versus 10.9%, P =.007), as well as greater age, weight, and serum ferritin and iron concentrations. Logistic regression was used to examine the effects of high body mass index (more than 25 kg/m(2)), advanced age (older than 34 years), parity of 1 or more, and hemoglobin in the highest quartile, on the incidence of GDM. Only advanced age (odds ratio 3.79, 95% confidence interval 2.33, 6.17) and hemoglobin in the highest quartile (odds ratio 1.73, 95% confidence interval 1.08, 2.78) emerged to be significant factors.
  
  
  CONCLUSIONS
  A high maternal hemoglobin (more than 13 g/dL) at the initial prenatal visit in Chinese women is an independent risk factor for GDM. This may reflect a better nutritional status in these women, as suggested by the increased iron status.
authors.affiliation: Department of Obstetrics and Gynecology, The University of Hong Kong, Hong Kong, China. laotth@hkucc.hku.hk
authors.forename: Terence T
authors.initials: TT
authors.lastname: Lao
authors.forename: Louis Y
authors.initials: LY
authors.lastname: Chan
authors.forename: Kar Fai
authors.initials: KF
authors.lastname: Tam
authors.forename: Lai Fong
authors.initials: LF
authors.lastname: Ho
mesh_terms: D001835:Body Weight; D016640:Diabetes, Gestational / Q000097:blood* / Q000208:ethnology*; D004909:Erythrocyte Indices; D005260:Female; D005293:Ferritins / Q000097:blood; D006454:Hemoglobins / Q000032:analysis*; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D007501:Iron / Q000097:blood; D008423:Maternal Age; D010298:Parity; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D011446:Prospective Studies; D012044:Regression Analysis; D012307:Risk Factors
chemical_list: D006454:Hemoglobins; D005293:Ferritins; D007501:Iron