If you have gestational diabetes, the chances of having problems with the pregnancy can be reduced by controlling your blood sugar (glucose) levels.
You'll also need to be more closely monitored during pregnancy and labour to check if treatment is working and for any problems.
Checking your blood sugar level
You'll be given a testing kit that you can use to check your blood sugar (glucose) level.
This involves using a finger-pricking device and putting a drop of blood on a testing strip.
You'll be advised:
- how to test your blood sugar level correctly
- when and how often to test your blood sugar – you'll usually be advised to test before breakfast and 1 hour after each meal
- what level you should be aiming for – this will be a measurement given in millimoles of glucose per litre of blood (mmol/l)
- how to share your blood sugar levels with your care team, to help you get the right advice and treatment
If you take insulin and have problems with low blood sugar (hypoglycaemia) or your blood sugar is not stable, your care team might offer you a continuous glucose monitor (CGM).
This is a small sensor you wear on your skin that sends data wirelessly to a receiver or a mobile phone, so you can see your blood sugar level at any time.
A healthy diet
Making changes to your diet can help control your blood sugar levels.
You should be referred to a dietitian, who can give you advice about your diet and how to plan healthy meals.
You may be advised to:
- eat regularly – usually three meals a day – and avoid skipping meals
- eat starchy and low glycaemic index (GI) foods that release sugar slowly – such as wholewheat pasta, brown rice, granary bread, all-bran cereals, pulses, beans, lentils, muesli and plain porridge
- eat plenty of fruit and vegetables – aim for at least 5 portions a day
- avoid sugary foods – you do not need a completely sugar-free diet, but swap snacks such as cakes and biscuits for healthier alternatives such as fruit, nuts and seeds
- avoid sugary drinks – diet or sugar-free drinks are better than sugary versions. Fruit juices and smoothies can also be high in sugar, and so can some "no added sugar" drinks, so check the nutrition label or ask your health care team
- eat lean sources of protein, such as fish
It's also important to be aware of foods to avoid during pregnancy, such as certain types of fish and cheese.
Physical activity lowers your blood glucose level, so regular exercise can be an effective way to manage gestational diabetes.
You'll be advised about safe ways to exercise during pregnancy. Find out more about exercise in pregnancy.
A common recommendation is to aim for at least 150 minutes (2 hours and 30 minutes) of moderate-intensity activity a week, plus strength exercises on 2 or more days a week.
You may be given medicine if your blood sugar levels are still not stable 1 to 2 weeks after changing your diet and exercising regularly, or if your blood sugar level is very high when you're first diagnosed. This may be tablets – usually metformin – or insulin injections.
Your blood sugar levels can increase as your pregnancy progresses, so even if they improve at first, you may need to take medicine later in pregnancy.
You can usually stop taking these medicines after you give birth.
Metformin is taken as a tablet up to 3 times a day, usually with or after meals.
Side effects of metformin can include:
- feeling sick
- being sick
- stomach cramps
- loss of appetite
Occasionally a different tablet called glibenclamide may be prescribed.
Insulin may be recommended if:
- you cannot take metformin or it causes side effects
- metformin does not lower your blood sugar levels enough
- you have very high blood sugar
- your baby is very large or you have too much fluid in your womb (polyhydramnios)
You inject insulin using an insulin pen. This is a device that helps you inject safely and take the right dose.
Using an insulin pen does not usually hurt. The needles are very small, as you only inject a small amount just under your skin. You'll be shown where to inject and how to use your pen.
Depending on the type of insulin you're prescribed, you may need to take it before meals, at bedtime, or on waking.
You will be told how much insulin to take. Blood sugar levels usually increase as pregnancy progresses, so your insulin dose may need to be increased over time.
Insulin can cause your blood sugar to fall too low (hypoglycaemia). Symptoms of low blood sugar include feeling shaky, sweaty or hungry, turning paler than usual, or finding it difficult to concentrate.
If this happens, test your blood sugar, and treat it straight away if it's low. Find out how to treat low blood sugar.
You'll be given information about hypoglycaemia if you're prescribed insulin.
Monitoring your pregnancy
Gestational diabetes can increase the risk of your baby developing problems, such as growing larger than usual.
Because of this, you'll be offered extra antenatal appointments so your baby can be monitored.
Appointments you should be offered include:
- an ultrasound scan at around week 18 to 20 of your pregnancy to check your baby for abnormalities
- ultrasound scans at week 28, 32 and 36 – to monitor your baby's growth and the amount of amniotic fluid, plus regular checks from week 38 onwards
The ideal time to give birth if you have gestational diabetes is usually around weeks 38 to 40.
If your blood sugar is within normal levels and there are no concerns about your or your baby's health, you may be able to wait for labour to start naturally.
Earlier delivery may be recommended if there are concerns about your or your baby's health, or if your blood sugar levels have not been well controlled.
You should give birth at a hospital where specially trained health care professionals are available to provide appropriate care for your baby.
When you go into hospital to give birth, take your blood sugar testing kit with you, plus any medicines you're taking.
Usually you should keep testing your blood sugar and taking your medicines until you're in established labour or you're told to stop eating before a caesarean section.
During labour and delivery, your blood sugar will be monitored and kept under control. You may need to have insulin given to you through a drip, to control your blood sugar levels.
You can usually see, hold and feed your baby soon after you've given birth. It's important to feed your baby as soon as possible after birth (within 30 minutes) and then at frequent intervals (every 2-3 hours) until your baby's blood sugar levels are stable.
Your baby's blood sugar level will be tested starting 2 to 4 hours after birth. If it's low, your baby may need to be temporarily fed through a tube or a drip.
If your baby is unwell or needs close monitoring, they may be looked after in a specialist neonatal unit.
Any medicines you were taking to control your blood sugar will usually be stopped after you give birth. You'll usually be advised to keep checking your blood sugar for 1 or 2 days after you give birth.
If you're both well, you and your baby will normally be able to go home after 24 hours.
You should have a blood test to check for diabetes 6 to 13 weeks after giving birth. This is because a small number of women with gestational diabetes continue to have raised blood sugar after pregnancy.
If the result is normal, you'll usually be advised to have an annual test for diabetes. This is because you're at an increased risk of developing type 2 diabetes – a lifelong type of diabetes – if you've had gestational diabetes.
Video: gestational diabetes
This video gives advice about gestational diabetes and Kimberly talks about her pregnancy after being diagnosed.
Media review due: 1 March 2025
Page last reviewed: 08 December 2022
Next review due: 08 December 2025