Gestational diabetes explained

Gestational diabetes is a condition that occurs during pregnancy and which can lead to serious complications. Both mother and child also have an increased risk for developing diabeteslater in life.

Diabetes means that your blood glucose (also called blood sugar) is too high. Your body uses glucose for energy. But too much glucose in your blood can be harmful.

What causes gestational diabetes?
Changing hormones and weight gain are part of a healthy pregnancy. But both changes make it hard for your body to keep up with its need for a hormone called insulin. When this happens, your body doesn't get the energy it needs from the food you eat.

What is my risk of gestational diabetes?
To learn your risk for gestational diabetes, check each item that applies to you. Talk with your doctor about your risk at your first prenatal visit.

• I have a parent, brother or sister with diabetes.
• I am of Indian descent.
  
• I am 25 years old or older.
• I am overweight.
• I have had gestational diabetes before or I have given birth to at least one baby weighing more than 4kg.
• I have been told that I have "pre-diabetes", a condition in which blood-glucose levels are higher than normal, but not yet high enough for a diagnosis of diabetes. Other names for it are "impaired glucose tolerance" and "impaired fasting glucose".

If you checked any of these risk factors, ask your healthcare team about testing for gestational diabetes.

• You're at high risk if you're very overweight, have had gestational diabetes before, have a strong family history of diabetes, or have glucose in your urine. 
• You're at average risk if you checked one or more of the risk factors.
• You're at low risk if you didn't check any of the risk factors.

When will I be checked for gestational diabetes?
Your doctor will decide when you need to be checked for diabetes depending on your risk factors.

• If you're at high risk, your blood-glucose level may be checked at your first prenatal visit. If your test results are normal, you'll be checked again sometime between weeks 24 and 28 of your pregnancy.
• If you have an average risk for gestational diabetes, you'll be tested sometime between weeks 24 and 28 of pregnancy.
• If you're at low risk, your doctor may decide that you don't need to be checked.

How is gestational diabetes diagnosed?
Your healthcare team will check your blood-glucose level. Depending on your risk and your test results, you may have one or more of the following tests:

• Fasting blood glucose or random blood-glucose test
  Your doctor may check your blood-glucose level using a fasting blood-glucose test. Before this test, your doctor will ask you to fast, which means having nothing to eat or drink except water for at least eight hours. Or your doctor may check your blood glucose at any time during the day. This is called a random blood-glucose test. These tests can find gestational diabetes in some women, but other tests are needed to be sure diabetes isn't missed.
   
• Screening glucose challenge test
  For this test, you'll drink a sugary beverage and have your blood-glucose level checked an hour later. This test can be done at any time of the day. If the results are above normal, you may need further tests.
   
• Oral glucose tolerance test
  If you have this test, your healthcare provider will give you special instructions to follow. For at least 3 days before the test, you should eat normally. Then you'll fast for at least 8 hours before the test.
  
  The healthcare team will check your blood-glucose level before the test. Then you'll drink a sugary beverage. The staff will check your blood-glucose levels one, two and three hours later. If your levels are above normal at least twice during the test, you have gestational diabetes.

How will gestational diabetes affect my baby?
Untreated or uncontrolled gestational diabetes can mean problems for your baby, such as:

• Being born very large and with extra fat; this can make delivery difficult and more dangerous for your baby.
• Low blood glucose right after birth.
• Breathing problems.

If you have gestational diabetes, your healthcare team may recommend some extra tests to check on your baby, such as:

• An ultrasound exam, to see how your baby is growing.
• "Kick counts" to check your baby's activity (the time between the baby's movements) or special "stress" tests.

Working closely with your healthcare team will help you give birth to a healthy baby. Both you and your baby are at increased risk for type 2 diabetesfor the rest of your lives.

How is gestational diabetes treated?
Treating gestational diabetes means taking steps to keep your blood-glucose levels in a target range. You'll learn how to control your blood glucose using:

• A meal plan
• Physical activity
• Insulin (if needed)

Meal plan
You will talk with a dietician or a diabetes educator who will design a meal plan to help you choose foods that are healthy for you and your baby. Using a meal plan will help keep your blood glucose in your target range. The plan will provide guidelines on which foods to eat,how much to eat, and when to eat. Choices, amounts and timing are all important in keeping your blood-glucose levels in your target range.

You may be advised to:

• Limit sweets.
• Eat three small meals and one to three snacks every day.
• Be careful about when and how much carbohydrate-rich food you eat; your meal plan will tell you when to eat carbohydrates and how much to eat at each meal and snack.
• Include fibre in your meals in the form of fruits, vegetables and wholegrain crackers, cereals and bread.

Physical activity
Physical activity, such as walking and swimming, can help you reach your blood-glucose targets. Talk with your healthcare team about the type of activity that's best for you. If you're already active, tell your healthcare team what you do.

Insulin
Some women with gestational diabetes need insulin, in addition to a meal plan and physical activity, to reach their blood-glucose targets. If necessary, your healthcare team will show you how to give yourself insulin. Insulin isn't harmful for your baby. It cannot move from your bloodstream to the baby's.

How will I know whether my blood-glucose levels are on target?
Your healthcare team may ask you to use a small device called a blood-glucose meter to check your levels on your own. You'll learn:

• How to use the meter
• How to prick your finger to obtain a drop of blood
• What your target range is
• When to check your blood glucose

You may be asked to check your blood glucose:

• When you wake up
• Just before meals
• 1 or 2 hours after breakfast
• 1 or 2 hours after lunch
• 1 or 2 hours after dinner

The following chart shows blood-glucose targets for most women with gestational diabetes. Talk with your healthcare team about whether these targets are right for you.

Blood-glucose targets for most women with gestational diabetes:

• Before meals: less than 5.5 mmol/L
• 2 hours after a meal: less than 7 mmol/L

Each time you check your blood glucose, write down the results in a record book. Take the book with you when you visit your healthcare team. If your results are often out of range, your healthcare team will suggest ways you can reach your targets.

After I have my baby, how can I find out whether my diabetes is gone?
You'll probably have a blood-glucose test six to 12 weeks after your baby is born to see whether you still have diabetes. For most women, gestational diabetes goes away after pregnancy. You are, however, at risk of having gestational diabetes during future pregnancies or getting type 2 diabetes later.

How can I prevent or delay getting type 2 diabetes later in life?

• Reach and maintain a reasonable weight. Even if you stay above your ideal weight, losing 5 to 10% of your body weight is enough to make a big difference. For example, if you weigh 80kg, losing 4-8kg can greatly reduce your chance of getting diabetes.
• Be physically active for 30 minutes most days. Walk, swim, exercise or go dancing.
• Follow a healthy eating plan. Eat more grains, fruits and vegetables. Cut down on fat and kilojoules. A dietician can help you design a meal plan.

Remind your healthcare team to check your blood-glucose levels regularly. Women who have had gestational diabetes should continue to be tested for diabetes or pre-diabetes every one to two years. Diagnosing diabetes or pre-diabetes early can help prevent complications such as heart disease later.

Your child's risk for type 2 diabetes may be lower if you breastfeed your baby and if your child maintains a healthy weight.