Gestational diabetes

Diabetes can occur temporarily during pregnancy. This condition is commonly known as gestational diabetes. Significant hormonal changes during pregnancy can lead to blood sugar elevation in genetically predisposed individuals. Blood sugar elevation during pregnancy is called gestational diabetes. Pregnant women who have never had diabetes before but who have high blood sugar (glucose) levels during pregnancy are said to have gestational diabetes. Gestational diabetes affects about 4 percent of all pregnant women - about 135,000 cases of gestational diabetes in the United States each year.

What causes gestational diabetes?

No one knows for sure what causes gestational diabetes. The placenta supports the baby as it grows. Hormones from the placenta help the baby develop. But these hormones also block the action of the mother's insulin in her body. This problem is called insulin resistance. Insulin resistance makes it hard for the mother's body to use insulin. She may need up to three times as much insulin. Gestational diabetes starts when your body is not able to make and use all of the insulin it needs for pregnancy. Without enough insulin, glucose cannot leave the blood and be changed to energy.

How is gestational diabetes determined?

For many years, pregnant women took an oral glucose resistance test at the 28-week mark of their pregnancy. Doctors now believe it is important to test for gestational diabetes earlier in pregnancy - at 16 weeks - to manage the symptoms should gestational diabetes be discovered.

How does gestational diabetes affect the baby?

Gestational diabetes affects the mother after the baby's body has been formed, but while the baby is busy growing. Because of this, gestational diabetes does not cause the birth defects often seen in babies whose mothers were diabetic before pregnancy.

Untreated or poorly controlled gestational diabetes can harm the baby, because while the excess insulin present during gestational diabetes does not cross the placenta, the excess glucose in the bloodstream does. The baby's pancreas is faced with the challenge of producing extra insulin to deal with the extra blood glucose. Because of the extra insulin made by the baby's pancreas, newborns may have very low blood glucose levels at birth and are also at higher risk for breathing problems. Babies with excess insulin become children who are at risk for obesity and adults who are at risk for type 2 diabetes.

The excess glucose also can cause the baby to get fatter than it needs to be, since it has more energy that it needs to grow and develop.

Treating gestational diabetes

Because gestational diabetes can hurt both mom and baby, treatment is generally recommended. Treatment for gestational diabetes aims to keep blood glucose levels equal to those of pregnant women who don't have gestational diabetes. Treatment for gestational diabetes includes special meal plans and scheduled physical activity. It may also include daily blood glucose testing and insulin injections.

Gestational diabetes: after the baby is born

The good news is that gestational diabetes usually resolves once the baby is born. The bad news, however, is that 25 to 50 percent of women with gestational diabetes will eventually develop type 2 diabetes later in life, especially in those who require insulin during pregnancy and those who remain overweight after their delivery.

Patients with gestational diabetes usually undergo an oral glucose tolerance test about six weeks after giving birth to determine if their diabetes has persisted beyond the pregnancy, and to assess the woman's future risk for developing diabetes.