First trimester gestational diabetes screening - Change in incidence and pharmacotherapy need

Diabetes Res Clin Pract. 2015 Jul;109(1):135-40. doi: 10.1016/j.diabres.2015.04.027. Epub 2015 Apr 25.


Aims: Adopting recommendations of the International Association of Diabetes in Pregnancy Study Groups (IADPSG) and the California Diabetes and Pregnancy Program, our institution implemented early gestational diabetes (GDM) screening. Our objective was to compare GDM diagnosis rates using the standard two-step approach versus early screening, and secondarily to compare pharmacotherapy needs and perinatal outcomes.

Methods: This retrospective study included singleton pregnancies diagnosed between 7/2010 and 6/2012. Two cohorts were compared; those diagnosed via two-step screening versus early screening diagnosis: HbA1c≥5.7% (39 mmol/mol) or fasting plasma glucose (FPG)≥92 mg/dL at ≤24 weeks gestation, or an abnormal 2-h oral glucose tolerance test (GTT) between 24 and 28 weeks. We calculated the rate of diagnosis, analyzed the need for pharmacotherapy, and reviewed neonatal outcomes.

Results: A total of 2652 patients were screened. GDM was diagnosed in 5.3% with two-step screening and 9.4% with early screening. Of those diagnosed via early screening with HbA1c, FPG, or both HbA1c and FPG, 49.2%, 66.7%, and 78.9% respectively required pharmacotherapy. In contrast, of those diagnosed with a 2-h GTT, 30.6% required pharmacotherapy (p<0.001). When controlling for confounders in a multivariable regression, BMI is most predictive of medication requirements (aOR 1.13, 95% CI 1.08-1.18, p<0.001). There were no differences in mean birth weight (3240±619 g vs. 3179±573 g, p=0.51) and macrosomia rates (7% vs. 2.5%, p=0.12).

Conclusion: Implementing early screening nearly doubled the incidence of GDM. Patients with early screening had a greater need for pharmacotherapy, but BMI was the best predictor of this outcome. There was no significant difference in neonatal outcomes.

Keywords: Early screening; Gestational diabetes; Incidence; Outcome; Pharmacotherapy.

MeSH terms

  • Adult
  • Birth Weight
  • Blood Glucose / analysis
  • California / epidemiology
  • Diabetes, Gestational / diagnosis*
  • Diabetes, Gestational / drug therapy
  • Diabetes, Gestational / epidemiology*
  • Early Diagnosis
  • Female
  • Gestational Age
  • Glucose Tolerance Test
  • Humans
  • Hypoglycemic Agents / therapeutic use
  • Incidence
  • Infant, Newborn
  • Mass Screening* / methods
  • Mass Screening* / statistics & numerical data
  • Pregnancy
  • Pregnancy Trimester, First*
  • Prenatal Diagnosis* / methods
  • Prenatal Diagnosis* / statistics & numerical data
  • Retrospective Studies
  • Young Adult


  • Blood Glucose
  • Hypoglycemic Agents