Gestational diabetes
Gestational diabetes is a form of diabetes that occurs during pregnancy. About one in
seven pregnant women will develop gestational diabetes. It is usually diagnosed around
24 to 28 weeks of pregnancy.
For most women, diabetes goes away after the baby is born. But there is an increased risk
of type 2 diabetes after pregnancy and a higher risk of developing gestational diabetes in
future pregnancies.
What is gestational diabetes?
Diabetes is a condition where there is too much
glucose (sugar) in the bloodstream. Glucose is
an important source of energy for your body. It
comes from carbohydrate (carb) foods that you
eat such as bread, pasta, rice, cereals, fruits,
starchy vegetables, milk and yoghurt. Your body
breaks down carbs that you eat into glucose. This
glucose then enters your bloodstream.
Insulin allows glucose from the bloodstream to
enter the body’s cells and be used for energy.
Insulin is made in the body by your pancreas.
During pregnancy, some of the hormones made
by the placenta reduce the action of insulin.
The pancreas then needs to make extra insulin
to keep blood glucose levels in the target range.
If the pancreas cannot make enough extra insulin,
blood glucose levels rise and gestational
diabetes develops.
Who is at risk of gestational
diabetes?
Women have an increased risk of gestational
diabetes when they:
• have had gestational diabetes in a previous
pregnancy
• have had elevated blood glucose levels in the
past
• are aged 40 years or over
• come from an Aboriginal or Torres Strait
Islander background
• are from an African, Melanesian, Polynesian,
South Asian, Chinese, Southeast Asian,
Middle Eastern, Hispanic or South American
Background.
have a family history of type 2 diabetes or a
first-degree relative (mother or sister) who has
had gestational diabetes
• have a weight above the healthy weight range
• have polycystic ovary syndrome
• have had a large baby (weighing more than
4,500 gram (g)) or complications in a previous
pregnancy
• are taking some types of antipsychotic or
steroid medications
• have gained weight too rapidly in the first half
of pregnancy.
How is gestational diabetes
diagnosed?
• All pregnant women should be tested for
gestational diabetes between 24 to 28 weeks
(unless they have been diagnosed with type 1
diabetes or type 2 diabetes before pregnancy).
• Women who have risk factors for gestational
diabetes may be tested earlier in their
pregnancy.
• Gestational diabetes is diagnosed using an
oral glucose tolerance test (OGTT). This is
done at a pathology lab. You will need to fast
overnight before having this test.
• Blood will be taken to check your fasting blood
glucose level. After this, you will be given a
sugary drink and have your blood tested one
and two hours later. You will be asked to sit
and wait between tests.
• If your blood glucose level is above the normal
range at your fasting, one or two-hour test,
you have gestational diabetes.
Why is it important to manage
gestational diabetes?
If your blood glucose levels are high during
pregnancy, glucose passes across the placenta
to the baby. This means the baby then makes
extra insulin. This can make the baby grow too
big and cause problems during labour, which
increases the risk of early delivery or the need for
a caesarean birth.
After the birth, the baby may have a greater
risk of low blood glucose levels (also known as
hypoglycaemia). This can occur because the
baby is no longer getting extra glucose from their
mother, but they continue to make extra insulin.
This causes their blood glucose levels to drop.
Women with gestational diabetes also have an
increased risk of developing high blood pressure
and a condition called pre-eclampsia during
pregnancy.
How is gestational diabetes
managed?
When you are diagnosed with gestational diabetes
there are health professionals who can help
you. These include specialist doctors, diabetes
educators and dietitians. They can work with you
to help keep your blood glucose levels within the
target range. This will provide the best outcome
for both you and your baby.
You can manage gestational diabetes by following
a healthy eating plan, doing regular physical
activity, and monitoring blood glucose levels. This
will help keep blood glucose levels within the
target range for a healthy pregnancy. It will also
help you to manage your pregnancy weight gain.
Some women will also need insulin injections or
medication to help manage gestational diabetes.
Healthy eating
Healthy eating is important to help keep your
blood glucose levels within the target range, and
to provide all your nutritional needs for pregnancy
and achieve a healthy pregnancy weight gain.
Eating well for gestational diabetes includes
choosing the right type and amount of carbs,
limiting foods high in saturated fat and eating a
variety of nutritious foods.
Choose the right type and amount of carb foods
Carbs are an important source of energy for
your body, especially during pregnancy. These
foods include breads and cereals, grains, starchy
vegetables such as potato, corn and sweet
potato, fruit, legumes, yoghurt and milk. To
manage your blood glucose levels, you need to
eat the right type and amount of carbs.
Eat some carbs at each meal and snack.
The best carb choices are those that are high in
fibre and have a lower glycemic index (GI). Low-GI
carbs include dense grainy/seeded breads, rolled
oats, natural muesli, pasta, low-GI white or brown
rice, milk, yoghurt, legumes and most fruit.
Spread carbs over three small meals and two or
three snacks. This can help keep blood glucose
levels in the target range and maintain your energy
levels. Large amounts of carb foods at any one
meal or snack can cause blood glucose levels to
rise too high.
Your dietitian can advise you on the amounts of
carbs that are right for you.
Avoid food and drinks that are high in added
sugars and have little nutritional value. These
include soft drinks, cordial, cakes, biscuits,
chocolates and lollies.
Limit foods high in saturated fat
Eat less saturated fat. Choose lean meats,
skinless chicken and low-fat dairy foods, and
avoid takeaway and processed foods.
Have small amounts of healthy fats, such as
olive oil or canola oil, unsalted nuts, seeds and
avocado.
Eat a variety of nutritious foods
Your body needs extra nutrients during pregnancy.
This includes iron and folate to help your baby
develop. Eating a wide variety of nutritious foods
including vegetables, fruits, lean meats, low-fat
dairy foods and wholegrain breads and cereals
– can help you to meet these extra nutritional
needs.
Food safety is also important during pregnancy.
Avoid high-risk foods such as processed meats,
uncooked meat, cold seafood, raw eggs, soft
cheeses and pre-prepared vegetables and salads.
A dietitian can advise you on how to meet your
nutritional needs during pregnancy. They can also
provide information on food safety and healthy
eating for gestational diabetes.
Physical activity
Physical activity can help you manage your blood
glucose levels and pregnancy weight gain. It will
keep you fit to prepare for the birth of your baby.
Being active also has other benefits, such as
managing pregnancy symptoms like heartburn,
constipation and lower back pain.
Talk to your doctor before starting or continuing
any form of physical activity while you are
pregnant.
It is important to try to be active every day when
you have gestational diabetes. Activities could
include swimming, brisk walking, pregnancy yoga
or pilates, and aqua fitness classes.
Talk to your diabetes educator about the effects of
exercise on your blood glucose levels, especially
if you are taking insulin.
Monitoring blood glucose levels
Blood glucose monitoring is an essential part
of managing gestational diabetes. A diabetes
educator can show you how to check your blood
glucose levels using a blood glucose meter and
advise you on target levels for pregnancy.
The most common times to check blood glucose
levels are when you wake up in the morning
(fasting) and one or two hours after the start of
each main meal. You may also be advised to
check your blood glucose levels at other times.
Regular blood glucose monitoring can help you
understand the effects of food and physical
activity on blood glucose levels. Keep a record of
your blood glucose readings so that your diabetes
health professionals can work with you to look for
any patterns in your blood glucose levels. They
can also advise you on what to do if your blood
glucose levels are outside the target range.
Medications
If your blood glucose levels are above the target
range, you may need medication to help manage
gestational diabetes. Most diabetes tablets are
not suitable for use during pregnancy, but a
medication called metformin is sometimes used.
Some women will need insulin injections to help
keep blood glucose levels in the target range.
Insulin dose not cross the placenta and will not
harm your baby. If you need insulin, your diabetes
educator will teach you how to give an injection.
Your insulin doses will also need to be reviewed
regularly.
Pregnancy weight gain
As your baby grows, it is normal to gain weight
during your pregnancy. Your recommended
weight gain during pregnancy depends on your
weight before you were pregnant. Discuss your
individual pregnancy weight gain targets with your
health professional.
Who can help with your gestational
diabetes?
Managing gestational diabetes is a team effort,
involving you, your partner, your family, and health
professionals. There are many different health
professionals who can help you, including:
• your general practitioner (GP)
• an endocrinologist (diabetes specialist)
• an obstetrician
• a diabetes educator or diabetes nurse
practitioner
• a dietitian
• an exercise physiologist or physiotherapist
• a midwife.
After gestational diabetes
You will be advised to have an oral glucose
tolerance test 6–12 weeks after your baby is
born, or as soon as possible after this time. This
is to check that your blood glucose levels have
returned to within the normal range.
Depending on your risk factors, you will also need
to have a check for type 2 diabetes every one to
three years. Ask your doctor for more information.
Gestational diabetes can occur again in future
pregnancies. You also have an increased risk of
developing type 2 diabetes.
You can reduce your risk by:
• being in the healthy weight range
• making healthy food choices
• being physically active every day.
• breastfeeding your baby.
If you develop type 2 diabetes, early diagnosis
and management are important for good
health, especially if you are planning for a future
pregnancy.
Babies born to women who have had gestational
diabetes also have an increased risk of childhood
obesity and type 2 diabetes later in life. It is
important for the whole family to eat well and
stay active to reduce this risk.
