Gestational diabetes is a type of diabetes that affects women during pregnancy. Diabetes is a condition caused by 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 slightly 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 that is first diagnosed during pregnancy. There are two other types of diabetes:
- type 1 diabetes – when the body produces no insulin at all (often referred to as insulin-dependent diabetes, juvenile diabetes or early-onset diabetes)
- type 2 diabetes – when the body doesn't produce enough insulin 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.
It is estimated that gestational diabetes affects up to 14 in every 100 pregnant women.
Outlook
Gestational diabetes can often be controlled with diet and exercise. One or two women in every 10 with gestational diabetes will require medication to control their blood glucose levels (see Gestational diabetes - treatment).
If gestational diabetes is not detected and controlled, it can increase the risk of birth complications, such as shoulder dystocia (when the baby’s shoulder gets stuck during the birth). It can also lead to babies being large for their gestational age. See Gestational diabetes - complications for more information about the risks of this condition.
In most cases, gestational diabetes develops in the second or third trimester (from week 14 of the pregnancy to the birth) and disappears after the baby is born. However, women who develop gestational diabetes are more likely to develop type 2 diabetes later in life.
