What is gestational diabetes?

Gestational diabetes is high blood sugar that starts or is first found during pregnancy. Pregnancy hormones make insulin work less well; most bodies make extra insulin to keep up, but some cannot make enough. It often causes no symptoms, so it is found with a routine test, usually at 24 to 28 weeks.

Last reviewed 2026-10-20. Written by the First Fork team from the published guidelines listed below; not reviewed by a clinician. This page is not medical advice.

How it happens

Insulin is the hormone that keeps blood sugar in range. In pregnancy, the body's hormones and other changes make cells use insulin less well, so the body needs more of it. Usually the body makes enough extra insulin. When it cannot, blood sugar rises.¹² In the US, it affects 5 to 9 percent of pregnancies every year.²

Who is at higher risk

• Gestational diabetes in an earlier pregnancy, or a baby who weighed over 9 pounds
• Overweight, or a family history of type 2 diabetes
• Polycystic ovary syndrome (PCOS)
• Being African American, Hispanic or Latino, American Indian, Alaska Native, Native Hawaiian or Pacific Islander²

It can also develop in people with no risk factors at all.¹ It is not caused by something you did wrong.

Why you probably felt nothing

Most of the time there are no symptoms; the diagnosis comes from a routine prenatal test.³ Some people are thirstier than normal or urinate more often.²

How it is found

Most people are tested between 24 and 28 weeks. People with risk factors are tested earlier.¹ The usual first step is a 1-hour glucose drink test; see failed the 1-hour glucose test.

How it is treated

• Checks and records. You check your blood sugar and have more prenatal visits.¹ See when to check and the targets. First Fork counts down each after-meal check from the first bite.
• Food and activity. For many people, a healthy diet and regular exercise are enough.¹ The ADA says studies find 70 to 85 percent manage it with lifestyle changes alone.⁴ See what to eat.
• Medicine, if needed. Some people need medicine, often insulin, to reach their targets.¹ See insulin for gestational diabetes.

Can you prevent it?

Before pregnancy, losing weight if you are overweight, eating well and being active may help prevent it. During pregnancy, do not try to lose weight; ask your doctor how much to gain.²

Does it go away?

Usually after the birth, but your risk of type 2 diabetes stays higher; see does gestational diabetes go away.

Questions

What causes gestational diabetes?

Pregnancy hormones make insulin work less well. When the body cannot make enough extra insulin, blood sugar rises.

What are the symptoms of gestational diabetes?

Most of the time there are none. Some people are thirstier or urinate more often. A routine test finds it.

Is gestational diabetes my fault?

No. It can develop in people with no risk factors at all.

Can I prevent gestational diabetes?

Before pregnancy, weight loss if you are overweight, healthy food and regular activity may help. During pregnancy, do not try to lose weight.

Sources

1. ACOG. Gestational Diabetes (FAQ 177, reviewed April 2026). https://www.acog.org/womens-health/faqs/gestational-diabetes
2. CDC. Gestational Diabetes. https://www.cdc.gov/diabetes/about/gestational-diabetes.html
3. MedlinePlus (US National Library of Medicine). Gestational diabetes. https://medlineplus.gov/ency/article/000896.htm
4. American Diabetes Association. 15. Management of Diabetes in Pregnancy: Standards of Care in Diabetes—2026. Diabetes Care 2026;49(Suppl. 1):S321. https://pmc.ncbi.nlm.nih.gov/articles/PMC12690181/

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