Pregnancy and baby

Diabetes and pregnancy

What is gestational diabetes?

Media last reviewed: 20/03/2014

Next review due: 20/03/2016

Diabetes and your unborn baby

Diabetes is a condition in which the amount of sugar (glucose) in the blood is too high. Glucose comes from the digestion of starchy foods, such as bread and rice. Insulin, a hormone produced by your pancreas, helps your body to use glucose for energy.

Three types of diabetes can affect you when you're pregnant. Type 1 and type 2 diabetes are long-term conditions that women may have before they get pregnant (pre-existing diabetes). Gestational diabetes develops only in pregnancy and goes away after the baby is born.

Most women with diabetes have a healthy baby, but diabetes does give you a higher risk of some complicataions.

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 need to 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. However, it can happen at a younger age, particularly in black and Asian 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 usually be treated with tablets to lower blood glucose, but some pregnant women require insulin injections.

Gestational diabetes

Gestational diabetes only occurs 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.

It's important to know that 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 develop problems with their eyes (called diabetic retinopathy) and their kidneys (diabetic nephropathy), or existing problems may get worse.

Your baby may be at risk of:

  • not developing normally and having congenital abnormalities – particularly heart and nervous system 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 controlled before you become pregnant. Ask your GP or diabetologist (diabetes specialist) for advice. You should 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 no more than 6.5% before you get pregnant, as long as this does not cause problems with hypoglycaemia. If your HbA1c is higher than this, you would benefit from getting your blood glucose under better control before you conceive, to reduce the risk of complications for you and your baby. Your GP or diabetes specialist can advise you on how best to do this.

If your HbA1c is very high (above 10%), your care team should strongly advise you not to try for a baby until it has fallen.

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 5 milligrams (mg) a day. Your doctor can prescribe this high-dose folic acid for you, as 5mg tablets are not available over the counter. Taking folic acid helps to prevent your baby from developing birth defects, such as spina bifida. You should take folic acid while you are trying to get pregnant, until you are 12 weeks pregnant.

Your treatment

Your diabetic treatment regime is likely to need adjusting during your pregnancy, 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 will be screened more often to check that they are 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 about treating a hypoglycaemic attack, and talk to your doctor or diabetes specialist.

Diabetic eye screening in pregnancy

If you have pre-existing diabetes (you had diabetes before you got pregnant) you will be offered diabetic eye screening at recommended intervals during pregnancy. This screening test is to check for signs of diabetic eye disease, including diabetic retinopathy.

Everyone with diabetes is offered diabetic eye screening, but screening is very important when you are pregnant, because the risk of serious eye problems is greater in pregnancy.

Diabetic eye screening is strongly recommended in pregnancy. It is part of managing your diabetes, and diabetic retinopathy is treatable, especially if it is caught early. If you decide not to have the test, you should tell the clinician looking after your diabetes care during pregnancy.

Read more about diabetic eye screening.

If you develop gestational diabetes

You're more likely to develop gestational diabetes if:

  • you're overweight, with a pre-pregnancy 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   

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.

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 have 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 your 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 on 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 to be large on an ultrasound scan, you may have to take tablets or give yourself insulin injections.

Whatever type of diabetes you have, you will have more frequent – and sometimes long – antenatal appointments to check you 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. 

Read 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 requires 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. Your baby may be given a drip to increase their blood glucose. 

Read more about special care for babies

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. Talk to your doctor about this.

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.

Page last reviewed: 18/03/2015

Next review due: 18/03/2017


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The 5 comments posted are personal views. Any information they give has not been checked and may not be accurate.

JayLW said on 25 August 2015

I was diagnosed with type 2 7 years ago and also have PCOS (diagnosed 17 years ago). I have a very supportive doctor and nurse team now, although previous doctors/nurses, even diabetes specialists haven't always been correct in their information or felt like they understood enough to advise you.

I have my first appointment tomorrow at the pre-conception diabetes clinic and having read this page, I now know what to expect. The first I knew that teams like this existed was through my current diabetic nurse of 1 year. Before this, whenever I spoke about pregnancy to any doc/nurse I was advised against it due to the extra risks so it was a shock when I found out whole teams existed for extra support.

Fingers crossed all goes well for me, but I hope anybody with diabetes who is thinking about pregnancy reads this page and gets themselves fully aware of the support that's available to them.

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darkangel1908 said on 27 December 2014

hi, i am a type 1 diabetic and just recently found out i am pregnant i believe i just bout a month gone and i am worried bout my babies health more then mine everything so far as gone great got first midwife appointment on tuesday my diabetes health as not always been the best so i hope if i keep it on track now it wow have any lasting effects on my pregnancy

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PoppyHStyles said on 26 September 2014

Hi, I have type 1 diabetes and I just wanted to read about having diabetes while being pregnant. I have had type 1 diabetes for about 4 (almost 5) years, and I am thinking to move on to the pump in the next few months. I also want to have children when I'm older! This page really helped me a lot!!

Thanks to the NHS for giving me this information!!

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A_M said on 08 July 2012

I have had a similar experience with my GP. I'm also type 2, 26 years old and expecting my first child. I was diagnosed as diabetic when I was 22 years old and immediately put under hospital care as my blood glucose control was quite bad. Initially I started off with diet control and then was put on metformin and glicazide.

Each time I went to the hospital I was asked if I could be pregnant or if I was planning on becoming pregnant and that if I was thinking about it I would need to let them know. When my glucose was satisfactory I was released into GP care. When I told them I was planning a family I was sent back to the hospital and the care I have received from there was fantastic. They do a great job and the best thing is you aren't left with any questions or confusions.

However for some components of my care I needed to see my GP and was given an appointment with a different one. I can't begin to tell you how upset I was when he looked baffled as I asked him for the high dosage of folic acid and he didn't think I'd need it! I didn't leave until I got it! It was a Friday and he said he would contact the hospital and if they said I needed it he would post me my prescription! I was already 5 weeks pregnant when I found out! My normal GP specialised in diabetes but even so I would expect all GPs to conform to a standard!

I agree with JJ12, look on the nhs website and check out the NICE guidelines and don't be afraid to question your doctors. If you have an underlying health problem then it is important you receive the relevant care otherwise it's you and your baby who miss out.

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JJ12 said on 06 March 2012

I am a type 2 diabetic, 29 years old and pregnant with first child.

I have to start by saying that the healthcare from the NHS since becoming pregnant has been first class so far.

However the availability of preconception advice was poor. Since being diagnosed as being diabetic I have never really been told that I shouldn’t get pregnant with high glucose levels. There appears to be a need for some education given the increasing number of diabetes being diagnosed.

When I approached my doctor for preconception advice, I had conflicting information from the doctors and specialist midwives. The doctor told me that I didn't need the high dose folic acid and was adamant that I should come off metformin, whilst the midwife and specialist nurse suggested otherwise. The doctor originally prescribed me the normal dose of folic acid and I had to fight for the folic acid. I also had to fight to be put on insulin before conceiving as I was also on gliclazide.

There is plenty of advice out there on the NHS website and NICE guidelines, however I was surprised by how little my doctor knew about diabetes and pregnancy.

I suggest that you should read up on diabetes and pregnancy before conceiving and don’t be afraid to question to the doctor if you get conflicting advice.

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Gestational diabetes

Cathy Moulton, a Diabetes UK care adviser, explains how gestational diabetes affects pregnant women. Kimberley, who was diagnosed with gestational diabetes, talks about the symptoms she experienced and how she dealt with the condition.

Media last reviewed: 03/03/2014

Next review due: 03/03/2016