title: First-trimester glycosylated hemoglobin in women at high risk for gestational diabetes.
abstract: BACKGROUND
  Our aim was to investigate the prognostic value of first-trimester glycosylated hemoglobin (HbA1c) in pregnant women with risk factors for developing gestational diabetes mellitus (GDM).
  
  
  METHODS
  This is an observational retrospective cohort study conducted at the Department of Obstetrics and Gynecology, University Hospital Bern, Switzerland. We included pregnant women at high risk for GDM (n = 208), who had an HbA1c measurement in the first trimester. We compared HbA1c values of women who later developed GDM with those who did not develop GDM. Diagnosis of GDM was made on the basis of a 75-g oral glucose tolerance test performed between 24 and 28 weeks of gestation. We further examined the prevalence of GDM in relation to the first-trimester HbA1c value.
  
  
  RESULTS
  The prevalence of GDM in our high-risk group was 14.7%. Women who developed GDM had significantly higher first-trimester HbA1c values [5.43 ± 0.31% (36 ± 3 mmol/mol) vs. 5.23 ± 0.28% (34 ± 3 mmol/mol); p = 0.0026]. Moreover, all pregnant women with HbA1c ≥ 6.0% (42 mmol/mol) developed GDM, whereas those with < 4.5% (26 mmol/mol) did not.
  
  
  CONCLUSIONS
  Women at risk for GDM have higher first-trimester HbA1c levels and values ≥ 6.0% (42 mmol/mol) are predictive of GDM. This information may be useful for counseling these women and providing appropriate advice on diet and lifestyle modification early in pregnancy.
authors.affiliation: Department for Gynecology and Obstetrics, Inselspital, University Hospital of Bern and University of Bern, Bern, Switzerland.
authors.forename: Sofia
authors.identifier: http://orcid.org/0000-0001-5996-4064
authors.initials: S
authors.lastname: Amylidi
authors.affiliation: Department for Gynecology and Obstetrics, Inselspital, University Hospital of Bern and University of Bern, Bern, Switzerland.
authors.forename: Beatrice
authors.identifier: http://orcid.org/0000-0001-6343-8016
authors.initials: B
authors.lastname: Mosimann
authors.affiliation: Department for Endocrinology and Diabetes, Inselspital, University Hospital of Bern and University of Bern, Bern, Switzerland.
authors.forename: Christoph
authors.identifier: http://orcid.org/0000-0003-1691-6059
authors.initials: C
authors.lastname: Stettler
authors.affiliation: Center of Laboratory Medicine, University Institute of Clinical Chemistry, Inselspital, University Hospital of Bern and University of Bern, Bern, Switzerland.
authors.forename: Georg Martin
authors.identifier: http://orcid.org/0000-0001-5689-4574
authors.initials: GM
authors.lastname: Fiedler
authors.affiliation: Department for Gynecology and Obstetrics, Inselspital, University Hospital of Bern and University of Bern, Bern, Switzerland.
authors.forename: Daniel
authors.identifier: http://orcid.org/0000-0001-7705-1584
authors.initials: D
authors.lastname: Surbek
authors.affiliation: Department for Gynecology and Obstetrics, Inselspital, University Hospital of Bern and University of Bern, Bern, Switzerland.
authors.forename: Luigi
authors.identifier: http://orcid.org/0000-0003-3957-3810
authors.initials: L
authors.lastname: Raio
mesh_terms: D000328:Adult; D016640:Diabetes, Gestational / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D015994:Incidence; D011237:Predictive Value of Tests; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000097:blood*; D018566:Pregnancy, High-Risk / Q000097:blood; D015995:Prevalence; D012372:ROC Curve; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human
keywords: Gestational diabetes mellitus; HbA1c; glycosylated haemoglobin; high-risk pregnancy; oral glucose tolerance test