Diabetes is a condition in which the amount of sugar (glucose) in the blood is too high because your body can’t store it properly. Glucose comes from the digestion of starchy foods, such as bread and rice. Insulin, a hormone produced by your pancreas, helps your body use glucose for energy.
Three types of diabetes can affect you when you're pregnant:
Type 1 diabetes
Type 1 diabetes develops when your body can't produce any insulin. It usually begins in childhood, and most women with type 1 diabetes will be aware of their condition before they become pregnant. People with type 1 diabetes take insulin to control their blood glucose.
Type 2 diabetes
Type 2 diabetes develops when your body can't produce enough insulin, or when the insulin that is produced doesn’t work properly. It often occurs in overweight people, and is usually diagnosed in women aged 40 or over. But it can happen at a younger age, particularly in Asian and black people.
You may be aware that you have type 2 diabetes before you become pregnant, or you may be diagnosed during your pregnancy. Type 2 diabetes can be treated with tablets to lower blood glucose and, in some cases, with insulin injections.
Gestational diabetes
Gestational diabetes occurs only in pregnancy. It can occur at any stage of pregnancy, but is more common in the second half. It occurs when your body can't produce enough extra insulin to meet the demands of pregnancy. Gestational diabetes goes away after you've given birth.
You're twice as likely to develop type 2 diabetes later in life if you have gestational diabetes when you're pregnant.
Having diabetes when you're pregnant can put you and your baby at risk of complications (see below). You can reduce this risk, but it partly depends on what type of diabetes you have.
If you already have diabetes
If you already have type 1 or type 2 diabetes, you may be at a higher risk of:
People with type 1 diabetes may have new problems, or existing problems that get worse, with their eyes (called diabetic retinopathy) and their kidneys (diabetic nephropathy).
Your baby may be at risk of:
- not developing normally and having congenital abnormalities, particularly heart abnormalities
- being stillborn or dying soon after birth
- having health problems shortly after birth (such as heart and breathing problems) and needing hospital care
- developing obesity or diabetes later in life
Reducing the risks if you have pre-existing diabetes
The best way to reduce the risk to your own and your baby’s health is to ensure that your diabetes is well controlled before you become pregnant. Ask your GP or diabetologist (diabetes specialist) for advice. You may be referred to a diabetic pre-conception clinic for support before you try to get pregnant. Find diabetes support services near you.
You should be offered a blood test called an HbA1c test, which helps to assess the level of glucose in your blood. It's best if the level is 6.1% before you get pregnant. If you score higher than this, you need to get your blood glucose under better control before you conceive in order to reduce the risk of complications for you and your baby. Your GP or diabetes specialist can discuss with you how best to do this.
Folic acid
Women with diabetes should take a higher dose of folic acid. The normal daily dose for women trying to get pregnant and for pregnant women is 400 micrograms. Diabetic women should take 5mg a day. Your doctor can prescribe this high-dose folic acid for you. Taking folic acid helps prevent your baby from developing birth defects, such as spina bifida. You should take folic acid until you are 12 weeks pregnant.
Your treatment
Your diabetic treatment regime may remain the same during pregnancy, or your team may adjust it, depending on your needs. If you take drugs for conditions related to your diabetes, such as high blood pressure, these may have to be altered.
It's very important to keep any appointments that are made for you, so that your care team can monitor your condition and react to any changes that could affect your own or your baby’s wellbeing.
Expect to monitor your blood glucose levels more frequently during pregnancy. Your eyes and kidneys may be screened more often to check that their health is not deteriorating in pregnancy, as eye and kidney problems can get worse. You may also find that as you get better control over your diabetes, you have more hypoglycaemic (low blood sugar) attacks. These are harmless for your baby, but you and your partner need to know how to cope with them. Find out more about treating a hypoglycaemic attack, and talk to your doctor or diabetes specialist.
Gestational diabetes
You're more likely to develop gestational diabetes if:
- you're overweight, with a BMI (body mass index) above 30 (use the BMI healthy weight calculator, but note that this calculator is not suitable for use during pregnancy)
- you've given birth to a large baby, weighing more than 4.5kg (9.9lb), in the past
- you've had gestational diabetes before
- you have a parent, brother, sister or grandparent with diabetes
- your origin is south Asian, black Caribbean or Middle Eastern, as these ethnic groups have a higher risk of developing gestational diabetes
If you're in any of these higher-risk categories, you should be offered a test to check for gestational diabetes. You may be given a home testing kit to check your blood glucose levels, or you may be offered an oral glucose tolerance test (OGTT or GTT) at 28 weeks or earlier if you've had gestational diabetes in the past.
A GTT test is a blood test that's done after a period of not eating. You'll be told how long not to eat for before the test (it's often overnight). You'll then be asked to drink a glucose drink and take another blood test two hours later.
If you're diagnosed with gestational diabetes, you're at risk of:
- having a large baby, which increases the risk of a difficult delivery, having your labour induced, or a caesarean section.
Your baby may be at risk of:
- stillbirth
- health problems shortly after birth (such as heart and breathing problems) and needing hospital care
- developing obesity or diabetes later in life
Controlling gestational diabetes
Gestational diabetes can often be controlled by diet. A dietitian will advise you how to choose foods that will keep your blood sugar levels stable. You'll also be given a kit to test your blood glucose levels. If your blood sugar levels are unstable, or your baby is shown on an ultrasound scan to be large, you may have to take tablets or give yourself insulin injections.
Whatever type of diabetes you have, you will have more frequent, and sometimes time-consuming, antenatal appointments to check your and your baby's progress. You will be offered advice on diet and treatments to control your blood glucose levels.
Labour and birth
If you have diabetes, it's strongly recommended that you give birth with the support of a consultant-led maternity team in a hospital. Find out more about where you can give birth, including in hospital.
Babies born to diabetic mothers are often larger than normal. This is because blood glucose passes directly from you to your baby, so if you have high blood glucose levels your baby will produce extra insulin to compensate. This can lead to your baby storing more fat and tissue. This in turn can lead to birth difficulties, which require the expertise of a hospital team.
After the birth
Two to four hours after your baby is born, they will have a heel prick blood test to check whether their blood glucose level is too low. Feed your baby as soon as possible after the birth (within 30 minutes) to help keep your baby’s blood glucose at a safe level.
If your baby’s blood glucose can't be kept at a safe level, they may need extra care. Find out more about special care for babies. Your baby may be given a drip to increase their blood glucose.
When your pregnancy is over, you won’t need as much insulin to control your blood glucose. You can decrease your insulin to your pre-pregnancy dose or, if you have type 2 diabetes, you can return to the tablets you were taking before you became pregnant.
If you had gestational diabetes, you can stop all treatment after the birth. You should be offered a test to check your blood glucose levels before you go home, and at your six-week postnatal check. You should also be given advice on diet and exercise.
