1. Home>
2. Specialties>
3. Women's Health>
4. Practice Watch

Screening and Follow-Up for Gestational Diabetes

High-risk individuals require both initial screening and repeated testing during and after pregnancy.

Identification and aggressive management of gestational diabetes mellitus (GDM) is associated with improved maternal and fetal outcomes. Several issues were addressed at the Fifth International Workshop-Conference on GDM, including pathophysiology and epidemiology, therapeutic interventions during pregnancy, effects on offspring, and maternal follow-up. The recommendations are based on the following strategies for maternal screening and follow-up.

Risk assessment should be performed at the first prenatal visit. Blood glucose testing is not routinely required in low-risk patients (who meet all of the following criteria):

• Member of an ethnic group (e.g., Caucasian) with a low prevalence of GDM
  
• No known diabetes in first-degree relatives
  
• Age 25
  
• Normal prepregnancy weight
  
• Normal birth weight
  
• No history of abnormal glucose metabolism
  
• No history of poor obstetric outcome
  

For average-risk patients (i.e., those who do not meet all of the above criteria), blood glucose testing should be performed at 24 to 28 weeks’ gestation. Either one-step or two-step oral glucose tolerance testing (OGTT) is appropriate.

High-risk patients should be tested as soon as possible. Factors conferring high risk include severe obesity; a strong family history of type 2 diabetes; or a previous history of GDM, impaired glucose metabolism, or glucosuria. High-risk individuals with negative initial results should be retested at 24 to 28 weeks’ gestation or when symptoms of hyperglycemia first occur.

Most women with GDM will eventually go on to develop type 2 diabetes. The following assessments are recommended after GDM:

• 1 to 3 days postdelivery: fasting or random OGTT to detect overt diabetes
  
• At postpartum visit: 75-g 2-hour OGTT to classify glucose metabolism
  
• 1 year postpartum and every 3 years: 75-g 2-hour OGTT to assess glucose metabolism
  
• Annually: fasting plasma glucose to assess glucose metabolism
  

Comment: Most U.S. obstetric practices routinely perform GDM screening on all patients regardless of risk. Screening everyone is sometimes easier than screening only those with risk factors; however, effective risk assessment ensures that we do not overscreen low-risk women or underscreen high-risk women. High-risk individuals require both initial screening and repeated testing during pregnancy. The recommendation perhaps most overlooked by clinicians is that routine postpartum metabolic assessments should be regularly and repetitively performed in women with a history of GDM.

— Ann J. Davis, MD

Published in Journal Watch Women's Health October 4, 2007

Citation(s):

Metzger BE et al. Summary and recommendations of the Fifth International Workshop-Conference on Gestational Diabetes Mellitus. Diabetes Care 2007 Jul; 30:suppl 2:251.