75 gram Glucose Tolerance Test (GTT) in Pregnancy in Bengaluru

Overview

The GTT test in pregnancy is a diagnostic test used to check how well a pregnant woman’s body processes glucose. It helps in detecting gestational diabetes mellitus (GDM), a condition where blood sugar levels become high during pregnancy. GDM can increase risks for both mother and baby if left untreated, but with timely diagnosis and management, most women can have healthy pregnancies.

The test involves drinking a measured amount of glucose and then checking blood sugar levels at specific intervals. The 75 gram glucose tolerance test is widely recommended by doctors as it provides reliable information about how efficiently the body is using insulin during pregnancy.

Why Is the Test Prescribed?

Doctors may recommend the gtt test in pregnancy in the following situations:

• Routine screening: Between 24–28 weeks of pregnancy, all women are usually screened for gestational diabetes.

• High-risk pregnancies: Women with risk factors such as obesity, advanced maternal age, family history of diabetes, or a previous history of gestational diabetes.
  

• Monitoring complications: If the mother experiences excessive weight gain, recurrent urinary infections, or if ultrasound suggests a larger-than-expected baby.

Early detection through the GTT helps prevent complications such as preeclampsia, premature delivery, or birth of very large babies (macrosomia).

Components / Parameters

The test evaluates the body’s response to a fixed glucose load. The parameters typically measured are:

• Fasting Blood Sugar – checked before glucose intake.
  

• 1-Hour Blood Sugar – taken one hour after consuming 75 g of glucose.
  
  

If any of these values are above the cut-off limits set by international guidelines, gestational diabetes may be diagnosed.

75 Gram Glucose Tolerance Test Procedure

The 75 gram glucose tolerance test procedure is simple but requires preparation:

1. The patient should fast overnight (8–10 hours).
   

2. A fasting blood sample is collected first.
   

3. The patient is asked to drink a solution containing 75 g of glucose dissolved in water.
   

4. Blood samples are then taken at one hour and two hours after drinking the solution.
   

5. Results are compared with standard cut-offs to determine glucose tolerance.
   

The entire procedure usually takes about 2–3 hours, and the patient should remain in the lab during the test.