From the Guidelines
The next step in managing a pregnant woman with a glucose challenge test result of 150 mg/dL is to proceed to a 100-g oral glucose tolerance test (OGTT), as the initial screening result indicates the need for further evaluation to diagnose gestational diabetes mellitus (GDM) 1.
The patient's glucose challenge test result of 150 mg/dL exceeds the threshold for a normal result, which, according to the American College of Obstetricians and Gynecologists (ACOG), can be any of the commonly used thresholds of 130,135, or 140 mg/dL for the 1-h 50-g glucose load test 1. Given this abnormal screening test result, further diagnostic testing is necessary to confirm the presence of GDM.
Key points to consider in the management of this patient include:
- The diagnosis of GDM is made when at least two of the four plasma glucose levels (measured fasting and at 1,2, and 3 h during the 100-g OGTT) meet or exceed the specified thresholds 1.
- The 100-g OGTT should be performed when the individual is fasting, with plasma glucose measurements taken at fasting, 1 hour, 2 hours, and 3 hours after glucose consumption 1.
- Early detection and management of GDM are crucial to prevent complications such as macrosomia, birth trauma, neonatal hypoglycemia, and increased risk of cesarean delivery.
In the context of real-life clinical medicine, it is essential to prioritize the diagnosis and management of GDM to minimize adverse outcomes for both the mother and the fetus. Therefore, proceeding with the 100-g OGTT is the most appropriate next step in the management of this patient 1.
From the Research
Next Steps in Managing a Pregnant Woman with a Glucose Challenge Test Result of 150 mg/dL
- The glucose challenge test (GCT) result of 150 mg/dL is above the typical threshold for a normal result, which is usually considered to be below 140 mg/dL 2, 3.
- According to the study by 2, a GCT cutoff of ≥135 mg/dL is recommended for twin pregnancies, and all patients with a GCT of ≥130 mg/dL underwent a 3-hour, 100-g oral glucose tolerance test.
- For a pregnant woman with a GCT result of 150 mg/dL, the next step would be to perform a 3-hour, 100-g oral glucose tolerance test to confirm the diagnosis of gestational diabetes mellitus (GDM) 2, 3.
- The 3-hour oral glucose tolerance test will help determine if the woman has GDM, and if so, what level of treatment is required to manage the condition 4, 5.
- It is essential to note that a single abnormal value on the 3-hour oral glucose tolerance test is associated with adverse maternal and neonatal outcomes, and therefore, accurate diagnosis and management are crucial 4.
Considerations for Gestational Diabetes Mellitus (GDM) Diagnosis and Management
- The diagnosis of GDM is typically made if two or more values on the oral glucose tolerance test are abnormal 2, 5.
- Women with a GCT result of ≥200 mg/dL may be at higher risk for adverse pregnancy outcomes, such as preeclampsia and shoulder dystocia, compared to those with a positive 3-hour glucose tolerance test following a GCT of 135 to 199 mg/dL 6.
- Fasting cutoff values for the 100-g oral glucose tolerance test are consistently higher in women diagnosed with GDM who require insulin to achieve adequate blood glucose control 5.