Alternative Names diabetes of pregnancy, glucose intolerance in pregnancy, sugar intolerance in pregnancy
Definition Gestational diabetes is a resistance to insulin which develops during pregnancy and usually resolves after delivery. Glucose is the main form of sugar in the body. Gestational diabetes occurs in 4% of all pregnancies.
What is going on in the body? Glucose is an important source of energy used by the body's cells. When a person eats, the pancreas normally makes extra insulin. The insulin causes the glucose in the blood to move inside the body's cells. In a woman with gestational diabetes, the hormones produced in pregnancy block the effects of insulin. Glucose then builds up in the blood and the cells are left without a main source of energy. The result is a high level of glucose in the blood, a condition known as hyperglycaemia. High blood sugar levels can damage the growth of the foetus. This may cause complications for both the mother and baby.
What are the signs and symptoms of the disease? Usually there are no symptoms of gestational diabetes. If symptoms develop, they are often mild and may include:
glucose in the urine sample taken in the doctor's office
being a member of an ethnic group with a high incidence of gestational diabetes. This includes women of Latino, African American, Native American, Asian, or Pacific Islands descent.
What can be done to prevent the disease? Gestational diabetes can sometimes be prevented by regular exercise and a balanced diet to maintain a healthy weight before conceiving and during pregnancy. It is important to let the doctor know if there is a family history of diabetes.
How is the disease diagnosed? Regular antenatal visits where the doctor checks blood pressure, weight gain, listens for foetal heart sounds and importantly checks the urine for sugar and protein usually helps to picks up the condition. If sugar is detected and or the patient is in a high risk category for gestational diabetes further tests are done.
The one-step approach is done with a gestational diabetes blood glucose test . The woman drinks a liquid containing 50 grams of glucose and the blood glucose level is measured an hour later.
The two-step approach starts with the same gestational diabetes blood glucose test as the one-step approach. If the woman's blood glucose is elevated on the first test, a diagnostic oral glucose tolerance test is done. The woman drinks a liquid containing 100 grams of glucose, and the blood glucose level is measured 1, 2, and 3 hours later.
If the blood glucose level is elevated in either of the approaches, a diagnosis of gestational diabetes is made.
What are the long-term effects of the disease? Complications for the mother include:
increased risk of birth trauma such as shoulder dystocia, which occurs when the baby's shoulder gets stuck during delivery
decreased ability of the baby to tolerate labour
What are the treatments for the disease? The goal of treatment is to bring blood glucose levels to normal, and to keep them there throughout the pregnancy. This will prevent complications for both mother and child. The diet should provide enough kilojoules and nutrients to allow appropriate weight gain in both mother and foetus. A dietician will provide counselling and education. If changing the diet does not control glucose levels, insulin injections may be needed.
Until recently, oral medications were not recommended for gestational diabetes. However, a recent study indicated that glyburide is safe and effective to take in the last 6 months of pregnancy.
What are the side effects of the treatments? hypoglycaemia, or low blood sugar, may result if too much insulin is given, or if meals are skipped. Hypoglycaemia should be avoided, because the foetus will also experience low blood sugar levels.
What happens after treatment for the disease? Pregnancy hormones drop dramatically after delivery, and a woman may no longer need insulin. High blood glucose levels usually go away after pregnancy. But 30% to 40% of women with gestational diabetes may develop type 2 diabetes at some time in their lives. obesity or a family history of diabetes may increase this risk. A balanced diet and exercise after delivery will help with weight loss and will lower the risk of diabetes in the future. At the examination 6 weeks after delivery, a oral glucose tolerance test can help determine if further treatment is needed.
How is the disease monitored? Women with gestational diabetes run a high risk of having it in future pregnancies. Women who previously had gestational diabetes but are not pregnant should have fasting blood sugar tests each year to detect diabetes.
Author: Eva Martin, MD Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
