6
Diagnosis and Assessment
Table 5. Screening for and Diagnosis of GDM
"One-step" (IADPSG consensus)
Perform a 75-g OGTT with plasma glucose measurement fasting and at 1 and 2 h, at
24-28 weeks of gestation in women not previously diagnosed with overt diabetes. e
OGTT should be performed in the morning aer an overnight fast of >8 h.
e diagnosis of GDM is made when any of the following plasma glucose values are
exceeded:
• Fasting : >92 mg/dl (5.1 mmol/L)
• 1h: >180 mg/dl (1 0.0 mmol/L)
• 2 h: >153 mg/dl (8. 5 mmol/L)
"Two-step" (NIH consensus)
Perform a 50-g GLT (nonfasting ), with plasma glucose measurement at 1h (Step 1), at
24-28 weeks of gestation in women not previously diagnosed with overt diabetes .
If the plasma glucose level measured 1h aer the load is >140 mg/dla (7.8 mmol/L),
proceed to 100-g OGTT (Step 2). e 100-g OGTT should be performed when the
patient is fasting.
e diagnosis of GDM is made when at least two of the following four plasma glucose
levels (measured fasting, 1h,2 h,3 h aer the OGTT) are met or exceeded :
Carpenter/Coustan OR National Diabetes Data Group
Fasting 95 mg/dl (5.3 mmol/L) 105 mg/dl (5.8 mmol/L)
1 h 180 mg/dl (10.0 mmol/L) 190 mg/dl (10.6 mmol/L)
2 h 155 mg/dl (8.6 mmol/L) 165 mg/dl (9.2 mmol/L)
3 h 140 mg/dl (7.8 mmol/L) 145 mg/dl (8.0 mmol/L)
a
e American College of Obstetricians and Gynecologists (ACOG) recommends a lower
threshold of 135 mg/dl (7.5 mmol/L) in high-risk ethnic minorities with higher prevalence of
GDM; some experts also recommend 130 mg/dl (7. 2 mmol/L).
Î Screen women with GDM for persistent diabetes at 6-12 weeks
postpartum, using a 75-g 2-h OGTT and the diagnostic cutpoints in
Table 5. (E)
Î Women with a history of GDM should have lifelong screening for the
development of diabetes or prediabetes at least every 3 years. (B)
Î Women with a history of GDM found to have prediabetes should
receive lifestyle interventions or metformin to prevent diabetes. (A)
Table 6. Common Comorbidities
• Hearing impairment
• Obstructive sleep apnea
• Fatty liver disease
• Low testosterone in men
• Periodontal disease
• Certain cancers
• Fractures
• Cognitive impairment, depression
