How do I interpret the OGTT in pregnancy?

Enter glucose fasting, at 1 hour and 2 hours. The calculator checks them against WHO/IADPSG thresholds (5.1 / 10.0 / 8.5 mmol / L). If at least one reaches its threshold, it is gestational diabetes.

What is the normal OGTT glucose in pregnancy?

Normal is below the thresholds: fasting under 5.1, 1 hour under 10.0, 2 hours under 8.5 mmol / L. Reaching or exceeding any of them indicates gestational diabetes.

How is gestational diabetes different from overt diabetes?

GDM is first detected in pregnancy with a moderate glucose rise. Very high values (fasting ≥ 7.0 or 2h ≥ 11.1 mmol / L) indicate overt diabetes, managed differently.

When is the test done?

Usually at 24–28 weeks in everyone without previously known diabetes. With risk factors (obesity, prior GDM, family history) — earlier, as the doctor advises.

Does the test diagnose by itself?

A doctor makes the diagnosis considering correct preparation and technique. The calculator only checks values against thresholds and shows whether there is reason for a diagnosis.

Oral glucose tolerance test (OGTT) in pregnancy: interpretation

The 75g oral glucose tolerance test (OGTT) detects gestational diabetes (GDM). Enter glucose fasting, at 1 hour and 2 hours (in mmol / L) — the calculator checks each against the WHO/IADPSG threshold and shows whether GDM is present. One value at or above threshold is enough.

Interpret the OGTT (75g glucose)

Enter fasting glucose (and 1- and 2-hour values if available) — the result appears instantly.

OGTT norms in pregnancy (75g glucose)

Gestational diabetes is diagnosed if at least one value reaches or exceeds a threshold: fasting 5.1 · 1h 10.0 · 2h 8.5 mmol / L. Below is normal.

Test point	Normal (below threshold)
Fasting	below 5.1 mmol / L
At 1 hour	below 10.0 mmol / L
At 2 hours	below 8.5 mmol / L

What the OGTT in pregnancy is

The oral glucose tolerance test (OGTT) measures glucose fasting and then 1 and 2 hours after a 75g glucose drink. It detects gestational diabetes — a glucose metabolism disorder that first appears in pregnancy.

It is usually done at 24–28 weeks in all pregnant people without previously known diabetes; earlier with risk factors.

Thresholds and how to read the result

Gestational diabetes is diagnosed if at least one value reaches a threshold: fasting ≥ 5.1, 1 hour ≥ 10.0, 2 hours ≥ 8.5 mmol / L. One exceedance is enough.

Very high values (fasting ≥ 7.0 or 2 hours ≥ 11.1 mmol / L) point to overt (newly detected) diabetes rather than gestational — this needs a separate approach.

What to do with gestational diabetes

GDM is mostly controlled with diet and physical activity; sometimes insulin is needed. Glucose self-monitoring and follow-up reduce risks for mother and baby.

After birth GDM usually resolves but requires glucose checks and raises the future diabetes risk. A doctor sets the specific plan.

A guide, not a diagnosis

The calculator helps you understand the test and prepare for a visit. Diagnosis and treatment are up to a doctor; correct test preparation and blood sampling matter.

Frequently asked questions

Enter glucose fasting, at 1 hour and 2 hours. The calculator checks them against WHO/IADPSG thresholds (5.1 / 10.0 / 8.5 mmol / L). If at least one reaches its threshold, it is gestational diabetes.
Normal is below the thresholds: fasting under 5.1, 1 hour under 10.0, 2 hours under 8.5 mmol / L. Reaching or exceeding any of them indicates gestational diabetes.
GDM is first detected in pregnancy with a moderate glucose rise. Very high values (fasting ≥ 7.0 or 2h ≥ 11.1 mmol / L) indicate overt diabetes, managed differently.
Usually at 24–28 weeks in everyone without previously known diabetes. With risk factors (obesity, prior GDM, family history) — earlier, as the doctor advises.
A doctor makes the diagnosis considering correct preparation and technique. The calculator only checks values against thresholds and shows whether there is reason for a diagnosis.

Glucose and other pregnancy tests — decode them together

Upload your report — AI reads glucose, the OGTT and other values, links them to the term and suggests what to discuss with your doctor.

Decode my lab results

This calculator is for reference and information only and is not a diagnosis. Gestational diabetes is diagnosed by a doctor.