GTT (75gm glucose)

The GTT 75‑gram glucose test (oral glucose tolerance test) evaluates how your body processes a 75 g oral glucose load to detect diabetes or gestational diabetes. After overnight fasting a baseline blood sample is taken, you drink the glucose solution, and blood glucose is measured at set intervals (commonly 1 and 2 hours). Results are compared to standard thresholds to diagnose impaired tolerance or diabetes.

The 75 g oral glucose tolerance test cost varies widely. On public systems (e.g., NHS) it’s free for pregnant women. In private settings prices typically run about £30–£80 (UK), ₹200–₹800 (India) or roughly $20–$200 (US), depending on lab and insurance. Check your local clinic or lab for exact fees and whether it’s covered by your antenatal care.

A positive glucose tolerance test means your blood sugar rose above the threshold, indicating gestational diabetes or impaired glucose regulation. Care typically includes dietary and exercise changes, regular glucose monitoring, and sometimes medication (metformin or insulin). You’ll receive closer pregnancy and fetal monitoring to reduce risks (large baby, pre‑eclampsia, delivery complications). Follow-up glucose testing is recommended after delivery.

A normal glucose tolerance test (75 g OGTT) in pregnancy is: fasting less than 92 mg/dL (5.1 mmol/L), 1‑hour less than 180 mg/dL (10.0 mmol/L), and 2‑hour less than 153 mg/dL (8.5 mmol/L). A 50 g screening test typically uses a 1‑hour cutoff around 130–140 mg/dL for further testing, but diagnosis relies on the 75 g OGTT thresholds above.

Gestational diabetes can cause fetal overgrowth (macrosomia), increasing risk of difficult delivery, shoulder injury and cesarean section. Babies may develop low blood sugar (neonatal hypoglycemia), breathing problems, jaundice and preterm birth. Uncontrolled maternal glucose also raises risks of stillbirth and long-term child obesity and type 2 diabetes. Good pregnancy monitoring and treatment reduce these risks.

No — you should fast before a 75 g oral glucose tolerance test. Typically you fast 8–14 hours and may drink only water; avoid food, sugary drinks, gum, and smoking. Take only medications your clinician permits and avoid heavy exercise beforehand. Follow your provider’s instructions and call them if you’re unsure about eating or taking medicines that could affect results.