Articles

Key takeaways

• Gestational diabetes is high blood sugar that develops during pregnancy.
• It is often managed with diet and exercise, sometimes with medication.
• Regular monitoring of blood sugar levels is important for your health.
• It usually resolves after birth, but increases future health risks.

What is gestational diabetes?

Gestational diabetes is a type of diabetes that develops during pregnancy. It means your body has trouble managing sugar (glucose). It usually starts in the middle or towards the end of pregnancy.

This happens because your body cannot make enough insulin to meet the extra needs of pregnancy. Insulin is a hormone that helps control your blood sugar levels.

Some pregnancy hormones can also stop insulin from working as it should. This is called insulin resistance.

Gestational diabetes is common. It affects at least 4 to 5 in 100 women during pregnancy. Some reports suggest it affects between 10 and 20 in every 100 pregnant women.

Screening and diagnosis

Most cases are found during screening tests. Your midwife will ask questions at your first appointment to see if you are at risk. If you are at risk, you should be offered a glucose test during pregnancy.

This may be a simple blood test in early pregnancy. You might also have a glucose tolerance test (GTT) between 24 and 28 weeks pregnant. A GTT involves fasting overnight, then having a blood test. You then drink a glucose drink, and the blood test is repeated later to see how your body reacts to the glucose.

If you had gestational diabetes in a previous pregnancy, you will be offered a test earlier. This could be a kit to check your own blood glucose levels or a GTT in early pregnancy. If these results are normal, you will be offered another GTT at 24 to 28 weeks.

Managing with diet and exercise

Gestational diabetes can often be managed by changing your diet and doing exercise. These changes can help to lower your blood sugar levels. Your healthcare team will give you information and support.

Changes to your diet

Aim to eat a healthy, balanced diet. This means a diet that is low in fat, sugar, and salt. It should also be high in fruits and vegetables.

Choose foods that release sugar slowly (low glycaemic index, or GI) where you can. This will help to manage your blood sugar levels. Do not try a weight-loss diet while you are pregnant, even if you have a higher body weight. Focus on eating well and staying active.

The focus is on the types of food you eat to manage blood sugar, not on eating less overall. Eating a balanced diet helps manage gestational diabetes. It also reduces the risk of complications.

Exercise recommendations

Gentle exercise can help to reduce your blood sugar levels. It also helps your body use insulin more effectively. Exercise can help you have a healthy pregnancy and cope better with labour and birth.

Exercise while pregnant is not dangerous for your baby. Your baby is safe and secure in your womb.

Aim for at least 150 minutes a week of moderate intensity activity. This is about 30 minutes a day, five days a week. Examples include fast walking and cycling. Try to include strength exercises on at least two days a week. These can include using weights or elastic resistance bands.

If you were active before pregnancy, aim to keep the same level of fitness. You may slow down towards the end of pregnancy as your bump grows.

If you are not very active, start slowly with something gentle. Try to do a little every day.

Safe exercise options

Good options include:

• Walking
• Swimming
• Cycling
• Pregnancy yoga
• Aquanatal classes

As a rule, you should still be able to talk as you exercise. If you get breathless, you are pushing yourself too hard. Do not overdo it and take breaks. Discuss your exercise plans with your healthcare team. They can advise you on what to do and for how long.

Monitoring, medication, and potential complications

If you have gestational diabetes, you will need to check your blood sugar levels. This is an important way to see if you are reaching your ideal blood sugar levels.

You will be given a kit to check your own blood sugar levels. This involves pricking your finger and putting a drop of blood on a testing strip.

Your healthcare team will show you how to check your blood sugar level. They will tell you when and how often to check.

This is usually when you wake up, and 1 hour after each meal. You will also learn what levels to aim for.

Your target blood sugar levels will vary throughout the day. For most pregnant women with gestational diabetes, ideal target levels are:

• Before breakfast (fasting) – less than 5.3 mmol/litre.
• 1 hour after meals – less than 7.8 mmol/litre.
• 2 hours after meals – less than 6.4 mmol/litre.

These numbers are general guidance. Follow your healthcare team's specific advice. You will be asked to keep a record of your blood sugar levels.

When medication may be needed

If your blood sugar levels do not reach the ideal range with diet and exercise, you may need medication. This also applies if an ultrasound scan shows your baby is larger than expected. If your glucose level is very high at diagnosis, you may be offered treatment straight away.

You will still be encouraged to make changes to your diet and exercise, even with medication.

Types of medication

• Metformin tablets – Often the first medication, metformin helps your body use insulin more effectively and reduces glucose production in the liver. Side effects like nausea or cramps can be minimized by starting with a low dose.
• Insulin injections – Insulin may be offered if metformin is insufficient, blood sugar is very high, or your baby is growing large. This hormone is injected under the skin, and your team will provide administration training.

Potential complications

Monitoring your blood sugar levels and meeting your targets will reduce your risk of complications. Most women with gestational diabetes have a healthy baby and a normal pregnancy. However, if left untreated, high blood sugar levels can cause serious health problems.

Risks for your baby

For your baby, complications can include:

• A large baby (macrosomia) – This is when your baby grows larger than normal and is heavier at birth. This can cause problems during birth, such as your baby's shoulder getting stuck during birth (shoulder dystocia).
• Low blood sugar after birth (neonatal hypoglycaemia) – this is when your baby's blood sugar is low.
• A higher risk of being very overweight (obesity) and developing type 2 diabetes – in later life.
• Yellowing of the skin and eyes (jaundice) – this can happen after birth and usually gets better on its own.
• Stillbirth – a small risk of your baby dying before or soon after birth. This is uncommon if gestational diabetes is detected and managed well. You should be offered extra ultrasound scans to monitor your baby's growth more closely.

Risks for you

For you, complications can include:

• High blood pressure (including pre-eclampsia) – a condition that can affect some pregnant women.
• Induced labour – having your labour started artificially.
• Caesarean section – a surgical birth.

Planning for birth and your postnatal health

Gestational diabetes can affect when and how you give birth. Your healthcare team will discuss your options for birth. They will help you make your birth plan.

Recommendations for birth

You will be advised to have your baby no later than 40 weeks and 6 days. If you do not go into labour naturally by then, you will be offered an induction (starting labour artificially) or a planned caesarean section. You may be advised to have your baby earlier if there are complications, such as:

• High blood sugar levels
• High blood pressure
• A big or small baby

Your baby's size will be monitored using ultrasound scans. If your baby is large, you may be advised to have an early induction or a planned caesarean section. You may still be able to have a vaginal birth if that is what you choose.

Your healthcare team will advise you to give birth in a hospital. This is because it has specially trained staff and equipment. This ensures you and your baby are looked after during and after labour.

During labour and birth, your blood glucose level will be carefully monitored. You may be advised to have an insulin drip to help control your blood glucose level.

After your baby is born

Your baby will stay with you unless they need extra care. Your baby will need to be fed soon after birth, usually within 30 minutes. They should then be fed every two to three hours after that. This helps keep your baby's blood sugar at a safe level.

A few hours after birth, your healthcare team will test your baby's blood sugar level. This is done by pricking their heel to get a drop of blood. If there are concerns, your baby may need extra care in a neonatal unit.

Gestational diabetes usually goes away after birth. If you are taking diabetes medication, it will be stopped straight after birth. Before you go home, your blood glucose level will be tested to make sure it is normal.

Your long-term health

You should have a blood test to check for diabetes 6 to 13 weeks after giving birth. You should then have an annual blood test if the result is normal. This is because women who have had gestational diabetes are more likely to develop:

• Gestational diabetes again – in future pregnancies.
• Type 2 diabetes – a lifelong type of diabetes. This is why regular checks are so important.

These checks help you and your GP monitor your health and take steps to lower your risk of developing type 2 diabetes. You can reduce your risk of future health issues by maintaining a healthy weight.

Reducing your future risk

Eating a balanced diet and exercising regularly also helps. A healthy lifestyle can also reduce your chances of getting gestational diabetes in any future pregnancies.

Speak to your GP if you develop symptoms of high blood sugar. These include increased thirst, needing to pee more often, and a dry mouth. Do not wait until your next test.

Your baby's long-term health

Your baby may also be at greater risk of being very overweight (obesity) or developing type 2 diabetes later in life. Breastfeeding can help reduce these risks for your baby. Helping your child exercise, eat healthy meals, and stay a healthy weight also helps.