For Physicians. By Physicians.™

ObGFirst: Get guideline notifications, fast. First month free!Click here

Updated ACOG Guidance on Gestational Diabetes


ACOG released updated guidance on gestational diabetes (GDM), which has become increasingly prevalent worldwide.  Class A1GDM refers to diet-controlled GDM. Class A2GDM refers to the clinical scenario where medications are required. Highlights and changes from the previous practice bulletin include the following:

Screening for GDM – First or Second Trimester?

  • ACOG supports the ‘2 step’ approach (24 to 28 week 1 hour venous glucose measurement following 50g oral glucose solution), followed by a 100g 3 hour oral glucose tolerance test (OGTT) if positive
    • Note: Diagnosis of GDM is based on 2 abnormal values on the 3 hour OGTT
      • ACOG recommends that currently there is insufficient evidence to diagnose GDM based on only one abnormal value
      • Patients with only one elevated value may require additional surveillance
  • ACOG does not recommend routine screening for GDM <24 weeks 
  • The USPSTF
    • Recommends screening for gestational diabetes in asymptomatic pregnant persons at ≥24 weeks of gestation or after (B recommendation)
    • Current evidence is insufficient to assess the balance of benefits and harms of screening for gestational diabetes in asymptomatic pregnant persons <24 weeks of gestation (I statement)
  • ACOG suggests use of Carpenter and  Coustan vs national Diabetes Data Group (NDDG) criteria due to higher thresholds with NDDG and possibility of missing patients who would benefit from GDM diagnosis
    • Fasting blood sugar: <95 mg/dL (5.3 mmol/L)
    • 1 hour blood sugar: <180 mg/dL (10.0 mmol/L)
    • 2 hour blood sugar: <155 mg/dL (8.6 mmol/L)
    • 3 hour blood sugar: <140 mg/dL (7.8 mmol/L) 

Note: ACOG does state that some practices may use the ‘one step’ 75g OGTT vs ‘2 step’ “if appropriate for the population they serve” 

Who Should be Screened Early?

Consider early screening in pregnancy if patient is overweight with BMI of 25 (23 in Asian Americans), and one or more of the following

  • Physical inactivity
  • Family history of diabetes – 1st degree relative (parent or sibling)
  • Black, Hispanic, Native American, Asian American, or Pacific Islander
  • Previous pregnancy history of
    • GDM
    • Macrosomia (≥ 4000 g)
  • Hypertension (140/90 mm Hg or being treated for hypertension) 
  • HDL cholesterol ≤ 35 mg/dl (0.90 mmol/L)
  • Fasting triglyceride ≥ 250 mg/dL (2.82 mmol/L)
  • PCOS
  • Conditions associated with insulin resistance (e.g., acanthosis nigricans, morbid obesity)
  • Hgb A1C ≥ 5.7%, impaired glucose tolerance or impaired fasting glucose | If A1C>6.5%, diagnosis of pregestational diabetes is met and GCT/GTT not needed
  • Cardiovascular disease
  • HIV
  • 35 years or older 
  • Other factors suggestive of increased risk for pregestational diabetes