Gestational Diabetes

What is gestational diabetes?

Diabetes mellitus is a condition where the pancreas (the organ responsible for producing insulin) is either unable to make insulin, or the insulin is unable to work effectively. The function of insulin is to keep the glucose levels within normal limits. With inadequate insulin, glucose builds up in the blood leading to high blood glucose levels causing health problems.

Gestational diabetes is a form of diabetes that some women develop during the 24th – 28th week of their pregnancy. Pregnant woman who have never had diabetes before, but who have high blood sugar (glucose) levels during pregnancy are said to have gestational diabetes. It usually disappears after delivery, and does not mean that the baby will be born with diabetes.

What are the causes of gestational diabetes?

The definite cause of gestational diabetes is not known, but it is assumed that as pregnancy progresses, the mother’s energy needs to increase. Also, placental hormones that help the baby grow and develop, block the action of the mother’s insulin. This is called insulin resistance. The pregnant woman needs extra insulin so that glucose can get from the blood into the cells where it is used for energy. If the body is unable to meet this requirement, then diabetes develops. When pregnancy ends and the insulin returns to normal, diabetes usually disappears.

Women who develop gestational diabetes have a greater risk of developing type II diabetes later.

What are the symptoms associated with gestational diabetes?

Diabetes often has no symptoms, which is why all pregnant women are routinely tested.

If symptoms occur, they may include:

  • Unusual thirst
  • Excessive hunger
  • Excessive urination
  • Frequent infections
  • High blood pressure

What increases the risk of getting gestational diabetes?

Any pregnant woman can develop gestational diabetes, but risk factors that increase susceptibility include:

  • Being overweight
  • A family history of diabetes
  • Woman with hypertension (high blood pressure)
  • Being over the age of 30 years (everyone’s tendency to develop diabetes
    increases with age)
  • Previous babies were large at birth (4kg and over)

Tell Dr Gailani if you have

  • Gestational diabetes in a previous pregnancy
  • Family history of gestational diabetes or diabetes 
  • Given birth to a baby weighing four kilos or over

What are the ill effects of gestational diabetes?

Although gestational diabetes usually goes away after delivery (when hormone levels return to normal), it still needs to be taken seriously.

  • The main concern is that it can increase the baby’s weight, and have other
    health effects on the unborn baby.
  • If the baby becomes very large (four kilos or more) it may be necessary
    for the woman to have a caesarean delivery, or for the doctor to induce the
    birth a little earlier, before the baby grows too big, but this can usually
    be avoided.
  • Women who develop gestational diabetes have about a 50% risk of
    developing type II diabetes later on.
  • Type II diabetes, which is increasingly common in people over the age
    of 40, is a chronic disease, which has to be carefully managed with healthy
    eating and regular physical activity. Sometimes, long-term medication is
    also needed. If type II diabetes isn’t controlled it can cause serious
    health problems including heart and kidney disease, and eye problems.
  • In severe cases, the baby may die in the uterus.

When gestational diabetes is well controlled, these risks are greatly reduced.

How is gestational diabetes diagnosed?

Pregnant woman are routinely checked for gestational diabetes between the 24th and 28th weeks of their pregnancy. Women at increased risk are usually tested earlier. The glucose challenge test involves taking a glucose drink, waiting for one hour and then having a blood test. If your glucose levels seem high, you will have a glucose tolerance test to confirm the diagnosis. This involves fasting from the night before the test, drinking a stronger glucose solution, and getting your blood tested two hours later.

How is gestational diabetes managed?

A woman with gestational diabetes needs careful monitoring for the remainder of her pregnancy.

Management is mainly aimed at changing to a healthy eating plan, physical activity and monitoring blood glucose levels. Specific management strategies include:

  • Eating regular meals. Hospital dieticians can advise on which foods to eat and which foods to avoid, and how often to eat.
  • Regular exercise to help reduce insulin resistance
  • Dietary modifications, such as switching to a low fat, high fibre diet
    with plenty of fresh foods
  • No alcohol or cigarettes
  • Regular blood tests performed at home to check glucose levels
  • Some woman may need to take medication, these may include tablets or insulin injections
RANZCOGCalvary John James HospitalCanberra HospitalAustralian  National UniversityWomens HealthICS