Gestational diabetes

Gestational diabetes usually doesn't cause any noticeable symptoms. If blood sugar levels increase a lot, it may lead to problems such as tiredness, physical weakness or increased thirst, like in other forms of diabetes. These symptoms tend to be mild, and are then often thought to be normal effects of pregnancy.

The hormones made in the body during pregnancy lead to changes in metabolism (chemical processes in the body). When we digest food and drinks, sugar enters our bloodstream. Due to the changes in pregnant women's metabolism, this sugar is absorbed more slowly by their cells, so their blood sugar levels rise. If their blood sugar regularly goes above a certain level, they are considered to have gestational diabetes.

High blood sugar levels are more common in women who

• are very overweight,
• have had gestational diabetes in the past, or
• have close relatives with diabetes.

Older women are also at greater risk of developing gestational diabetes.

Gestational diabetes usually doesn’t have any consequences for the mother and child. Babies born to women who have gestational diabetes have a slightly heavier birth weight on average. But this is not a reason for concern.

During the birth of larger babies, the phase after the head has come out often takes longer. If one of the child's shoulders gets stuck in the mother's pelvis (a situation known as “shoulder dystocia”), the child may not get enough oxygen. Midwives and doctors then react quickly, to be on the safe side. This can lead to minor injuries in the child and sometimes in the mother. Although these injuries usually heal well, being in that situation can be distressing for the mother. But emergency situations and more severe injuries are rare.

Higher blood sugar levels also increase the risk of a rare problem during pregnancy known as pre-eclampsia. In pre-eclampsia, more protein than normal is flushed out of your body in urine, your blood pressure increases, and fluid builds up in your body. If left untreated, pre-eclampsia can harm both the mother and the child.

Women who have gestational diabetes are more likely to develop type 2 diabetes later in life.

The best way to diagnose gestational diabetes is by doing a glucose tolerance test. This test measures how the body reacts to a large amount of glucose (sugar). It is offered in pregnancy between the start of week 24 and the end of week 27.

To find out whether it makes sense to do a glucose tolerance test, you will do what is known as a glucose challenge test first. This involves drinking a glass of water with sugar dissolved in it. One hour later, a sample of blood is taken from a vein in your arm to determine your blood sugar level. If the blood sugar level is found to be high, you will be asked to return to do a glucose tolerance test. This test is similar to the challenge test, but it involves more preparation and takes longer. For instance, it has to be done on an empty stomach.

The test results are documented in your maternity records. In Germany, the costs of glucose tolerance tests are covered by statutory health insurers.

Pregnant women who get enough exercise and eat a balanced diet are less likely to develop gestational diabetes than those who are overweight or eat a lot of carbohydrates. But it’s not unusual for pregnant women to have higher blood sugar levels than normal – simply because their metabolism is different.

A change in diet is usually enough to make the blood sugar levels return to normal. Women who have gestational diabetes can also seek advice from their doctor or a dietitian. Getting more exercise can help, too.

But some pregnant women have such high blood sugar levels for so long that they have to inject insulin or, in rare cases, take medicine for diabetes.

The doctor will offer to measure the woman’s blood sugar levels again after the baby is born. If her blood sugar levels have returned to normal, no more treatment is needed. All women who develop gestational diabetes are advised to talk with their doctor after the birth to decide whether more tests or lifestyle changes would be a good idea.

Because gestational diabetes usually doesn’t cause any noticeable symptoms, women are often surprised to find out that they have it. Many then start to worry about whether their baby is okay or whether the diabetes will cause problems during birth. Some may be afraid that they’ll still have diabetes after their baby is born. These kinds of concerns can be distressing during pregnancy. So it's important to know that most women with gestational diabetes give birth to healthy children.

The necessary changes in diet and physical activity may take some getting used to at first. But they can soon become a normal part of your daily life and help you keep fit after pregnancy too.

You will find more information on the management of gestational diabetes in this summary of the German "S3 Guideline."