Gestational diabetes is a type of diabetes that affects women during pregnancy. Diabetes is a condition where there is too much glucose (sugar) in the blood.

Normally, the amount of glucose in the blood is controlled by a hormone called insulin. However, during pregnancy, some women have higher than normal levels of glucose in their blood and their body cannot produce enough insulin to transport it all into the cells. This means that the level of glucose in the blood rises.

Types of diabetes

Gestational diabetes is diabetes first diagnosed during pregnancy. The two other main types of diabetes are:

  • type 1 diabetes  when the body produces no insulin at all (often referred to as juvenile diabetes or early-onset diabetes)
  • type 2 diabetes  when the body doesn't produce enough insulin and/or the body’s cells do not react to insulin (insulin resistance)

See the relevant links above for women who already had diabetes before they became pregnant.

How common is gestational diabetes?

Two to five in every 100 women giving birth in England and Wales has diabetes. Most of these women have gestational diabetes, and some have type 1 or type 2 diabetes.


Gestational diabetes can be controlled with diet and exercise. However, some women with gestational diabetes will need medication to control blood glucose levels. Read more about how gestational diabetes is treated.

If gestational diabetes is not detected and controlled, it can increase the risk of birth complications, such as babies being large for their gestational age (Macrosomia). Read about the complications of gestational diabetes for more information about the risks of this and related conditions.

In most cases, gestational diabetes develops in the third trimester (after 28 weeks) and usually disappears after the baby is born. However, women who develop gestational diabetes are more likely to develop type 2 diabetes later in life.

Gestational diabetes

Cathy Moulton, a Diabetes UK care adviser, explains how gestational diabetes affects pregnant women. Kimberley, who was diagnosed with gestational diabetes, talks about the symptoms she experienced and how she dealt with the condition.

Media last reviewed: 03/03/2014

Next review due: 03/03/2016

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Page last reviewed: 19/07/2012

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