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Diabetes in pregnancy

Diabetes in pregnancy

Having diabetes – or developing it – during pregnancy can make life complicated. There are more tests, scans and appointments to attend. And there are extra risks involved too, not just for you but also for your baby.
The good news, however, is that keeping on top of things like your blood sugar levels, getting regular check-ups and care from your GP or diabetes healthcare team, and taking any treatments you may need can help make sure you have a healthy pregnancy and a healthy baby.
According to experts, diabetes is the most common pre-existing medical disorder complicating pregnancy in the UK, with around five per cent of women giving birth in England and Wales having pre-existing diabetes or developing diabetes during pregnancy (gestational diabetes) (i). Of these women:

  • 7.5 per cent have type 1 diabetes

  • 5 per cent have type 2 diabetes

  • 87.5 per cent have gestational diabetes

How does pregnancy affect my blood sugar?

Diabetes is a condition that happens when you have too much sugar in your blood. With type 1, your blood sugar is too high because you don’t produce any insulin (the hormone that breaks down the sugar in your blood and allows your body’s cells to use it for fuel). Type 2, on the other hand, is when you either produce some insulin (but not enough to do its job properly) or the insulin you produce doesn’t work as it should.
Find out more details by reading our guide to diabetes causes and treatments.
Whether you already have diabetes or not, the hormones your body releases during pregnancy make it even harder for your cells to use insulin correctly. So if you do have diabetes and are pregnant, you’ll usually need more treatments and extra care to manage your condition.
If you’re pregnant but don’t already have diabetes, your body will usually produce more insulin to meet the demand. But not all women can produce the right amount, which makes their blood sugar levels too high. When this happens, you have gestational diabetes. The good news about gestational diabetes is that things usually return to normal straight or soon after you’ve given birth – though you will have to manage your blood sugar levels carefully, often with medication, while you’re pregnant.
Women who are more likely to develop gestational diabetes include:

  • Women who are pregnant at an older age

  • Women who have a body mass index of 30 or higher

  • Women who smoke

  • Women who have had gestational diabetes with a previous pregnancy

  • Women with a parent or sibling who has diabetes 

  • Women who have previously had a baby who weighed 4.5kg (10lb) or more at birth

  • Women who have had a previous unexplained stillbirth

  • Women of south Asian, Black, African-Caribbean or Middle Eastern origin


Does diabetes in pregnancy harm the baby?

If you already have type 1 or type 2 diabetes when you become pregnant, you may have a higher risk of:

  • Premature birth

  • Having a large baby, which can often mean a more difficult labour (for instance you may need to have your labour induced or you may need a caesarean section to deliver your baby)

  • Miscarriage 

  • Polyhydraminos (where there’s too much amniotic fluid in your womb) 

  • Problems with your eyes 

  • Problems with your kidneys 

  • Pre-eclampsia (high blood pressure and too much protein in your urine during the second half of your pregnancy) 

  • Blood clots 

  • Diabetic ketoacidosis (when your body produces harmful chemicals called ketones because it has a severe lack of insulin) 

High blood sugar levels can harm your baby too, increasing their risk of having health problems when they’re born. These include heart and breathing problems, or there’s a slightly higher chance they could be born with birth defects such as spina bifida (where the spine doesn’t develop properly). Later in life they too may develop diabetes plus there’s a greater risk of them putting on weight and becoming obese.
Meanwhile, though most women with gestational diabetes have otherwise normal pregnancies and healthy babies, they too have a higher risk of many of the problems that affect women with pregestational diabetes (that is, women who already have diabetes when they became pregnant).
But while all these risks sound alarming, they can be largely prevented. Read on to find out how.

How do I plan for pregnancy with diabetes?

If you’ve been diagnosed with type 1 or type 2 diabetes, it’s a good idea to get prepared before you even start trying for a baby. The first thing you may want to do is speak to your GP or diabetes specialist, who will usually refer you to a diabetic preconception clinic where you can get plenty of support and advice.
One of the things you should be advised to do is to have a special blood test – called a HbA1c test – every month. This is different from the blood sugar tests you might do yourself at home, as it assesses your blood sugar levels over a much longer period than a single day. This can help you to keep your blood sugar levels stable before you become pregnant.
According to the NHS you should aim for a HbA1c level of no more than 6.5 per cent (48mmol/mol) before becoming pregnant – if your HbA1c result is more than 10 per cent (86mmol/mol), you’ll be advised not to try for a baby until you can get it down to 6.5 per cent or lower (ii).
Your diabetes team will usually also give you targets for your daily blood sugar levels, and you may have to check your levels more frequently to make sure they are tightly controlled. Meanwhile if you take insulin to treat your diabetes, controlling your blood sugar more tightly than usual may mean you’ll become more susceptible to having hypos (hypoglycaemia – where your blood sugar drops too low, see our guide to diabetes  for more details). This means it’s even more important than usual to make sure you always have what you need to prevent or treat a hypo close by, such as a small carton of fruit juice, some glucose tablets or glucose gel.
If you have type 1 diabetes, your doctor will normally offer you a free continuous glucose monitor, a small device that sits just under your skin and monitors your sugar levels continuously. If for some reason you cannot use continuous glucose monitoring (CGM), you should be offered an alternative device for flash glucose monitoring, which is when your glucose levels are checked intermittently rather than continuously. Women with type 2 diabetes or gestational diabetes may also be offered CGM if their blood sugar levels are unstable or if they have severe hypos.
Women with type 1 diabetes are also usually offered a free test kit to check for diabetic ketoacidosis if they feel unwell.

What diabetes medication is safe during pregnancy?

Some diabetes medicines aren’t safe to take when you’re pregnant or planning a pregnancy, so always discuss this with your GP or diabetes specialist before you start trying for a baby. Insulin, however, is safe to take – though you may need to switch to a different type – as is another widely-used diabetes medicine called metformin.
Depending on whether or not you have any other health conditions, you may need to stop taking medications to treat them too, including certain blood pressure tablets and tablets called statins that are used to treat high cholesterol. However never stop taking any medicine without your doctor’s advice.
Women with diabetes are also advised to take a supplement containing five milligrams (5mg) of folic acid each day, from when they start trying for a baby until the 12th week of their pregnancy. This is a much higher dose than that for women who don’t have diabetes (the normal dose is 400 micrograms) and is only available on prescription, so you can only get it from your doctor or diabetes specialist. This will help prevent your baby developing birth defects such as spina bifida.

Eye and kidney problems in pregnancy for diabetics

When you’re pregnant it can make your risk for certain diabetes complications even higher, including eye problems and kidney problems. This is why it’s important to have your eyes and kidneys checked before you get pregnant, because spotting these problems early means they can be treated more effectively. Your GP, diabetes specialist or the person looking after your care at a diabetic preconception clinic can tell you more about having these tests.
Other tests you may be offered that could help reduce your risk of complications during pregnancy include:

  • Cholesterol and triglyceride blood tests

  • An electrocardiogram (this tests your heart’s rhythm and electrical activity)

  • Blood tests to check your liver function 

  • Foot checks to look for the early signs of diabetic foot ulcers


How is gestational diabetes treated?

Gestational diabetes affects at least four or five in every 100 women during pregnancy (iii). If you’re in a high-risk group for gestational diabetes (see above), you will usually be offered one or more tests to check for the condition early on in your pregnancy and/or when you’re between 24 and 28 weeks’ pregnant. Meanwhile women who aren’t in a high-risk group may be diagnosed with gestational diabetes if a routine anti-natal test shows they have sugar in their urine.
There are a number of different treatments for gestational diabetes, and which ones you’ll use will depend largely on how high your blood sugar levels are and what will would suit you best. The following are some of the treatments you may be offered:

Eating healthily and exercise

If you’re diagnosed with gestational diabetes, the first things you will usually be advised about will be your diet and how to stay active. Indeed, some women with gestational diabetes may need no further treatments if they can keep their blood sugar levels at a healthy level by eating healthily and exercising.
If you have gestational diabetes you should be given plenty of advice on what you should eat and what type of exercise you should do by a member of your diabetes care team. For general advice on healthy eating and exercise while living with diabetes, take a look at our guide to diabetes and your lifestyle

Blood sugar checking

Testing your blood sugar levels regularly can help you to keep yours under better control, which means the risks of gestational diabetes to you and your baby can be much lower. Women with gestational diabetes are often given blood glucose monitors so that they can check their levels themselves at home. This involves pricking your finger and putting a drop of your blood on a test strip, which is then analysed by the blood glucose monitor.
Your diabetes specialist or team will tell you when and how often to do the tests, as well as the blood sugar levels you should be aiming for (this will include the level you shouldn’t drop below to avoid your risk of having a hypo). If, however, you have regular or severe hypos, your specialist may give you a continuous glucose monitor to keep a constant check on your blood sugar.

Diabetes medicines

If following a healthy diet and staying physically active doesn’t keep your blood sugar levels at the right level, you may need to take medication while you’re pregnant. These medications include insulin and metformin. Your specialist can advise you exactly how you should take your medicines. You should, however, be able to stop taking these medicines straight after or soon after giving birth.

Can it be prevented?

Since we still don’t know exactly why some women develop gestational diabetes but not others, there’s no sure way to prevent it. But there are a few things you can do to reduce your risk of developing it, such as maintaining a healthy weight, eating a healthy diet and being physically active before you become pregnant.
However according to the charity Diabetes UK, having gestational diabetes not only increases your risk of developing it again if you have any more children, but it also increases your risk of developing type 2 diabetes after you’ve given birth (iv).
Indeed, according to the Royal College of Obstetricians and Gynaecologists, up to 50 per cent of women who’ve had gestational diabetes develop type 2 diabetes within the following five years (iii). Eating healthily, exercising and keeping your weight down can help reduce the risk of that happening. Diabetes UK also claims breastfeeding your baby can lower your risk of developing type 2 diabetes after having gestational diabetes (v).

How do I reduce my blood sugar levels?

If you have diabetes or you develop gestational diabetes, it’s really important to follow a healthy lifestyle. This includes eating a healthy balanced diet and staying physically active – your GP, diabetes specialist or a member of your diabetes care team can give you all the information you need on eating healthily and exercising while you’re pregnant. And like any other woman you should avoid drinking alcohol and smoking while you’re trying to get pregnant and throughout your pregnancy.

Meanwhile, you may want to consider taking certain supplements that have been shown to be helpful with blood sugar control – though always check with your GP or diabetes specialist before taking these or any other supplements, as there’s a chance your blood sugar could drop too low and cause a hypo. Some supplements also aren’t suitable to take during pregnancy, which is another good reason to check with a healthcare professional that they’re safe for you.

Natural supplements should also never be used as an alternative to conventional diabetes medicine or medical care. The following, however, are usually safe to take alongside conventional treatments if your doctor allows it.

The first supplement you may want to think about taking is a multivitamin and mineral product to make sure you’re getting all the nutrients your body needs at this special time. There are multivitamins designed especially for women to take before and during pregnancy – see our guide to multivitamins and daily requirements to find out more. However, if you’re already taking a prescription folic acid supplement, check with your doctor before taking a multivitamin product, as many also contain folic acid (that is, you may end up taking too much).
Some other supplements you may want to consider include the following:

Alpha lipoic acid

A powerful antioxidant, alpha lipoic acid is a fatty acid that may help control blood sugar levels (vi) as well as improve insulin sensitivity in people with type 2 diabetes (vii). Alpha lipoic acid is generally thought of as safe to take during pregnancy. However, pregnant women with diabetes must consult their GP or diabetes specialist before taking alpha lipoic acid as it may enhance insulin activity and increase their risk for hypos.


Some experts believe people who have diabetes also have low magnesium levels (viii), possibly because diabetes or some of the medicines used to treat it may cause magnesium deficiency. Elsewhere researchers have discovered magnesium may help with blood sugar control (ix).

High-strength fish oils

Omega-3 fatty acids – particularly EPA and DHA, two omega-3s found in oily fish such as salmon, trout, sardines and mackerel, as well as fish oil supplements – are widely considered helpful for general health and wellbeing. One study even suggests taking fish oil supplements combined with vitamin D supplements may have some benefits for women with gestational diabetes (x). However, make sure any fish oil supplement you take is suitable for pregnant women (cod liver oil, for example, isn’t suitable as it contains vitamin A, which can harm your unborn baby).
Fish oil supplements are widely available, and vegetarians and vegans can get these beneficial omega-3 fats too by taking supplements that contain omega-3 oils derived from marine algae.

Vitamin D

Best known for helping the body absorb calcium, vitamin D – and particularly having low levels of it – is increasingly being linked with type 2 diabetes (xi). Deficiency is also thought to be common in pregnant women, especially during the autumn and winter months, and may even be associated with an increased risk of gestational diabetes (xii). Indeed, according to the NHS, all women who are pregnant are recommended to take a daily vitamin D supplement (xiii).

The recommended form of vitamin D is vitamin D3 or cholecalciferol, as it’s the natural form of vitamin D that the body makes when exposed to sunlight. Vitamin D3 supplements are available in tablet form, and now you can get them in veggie-friendly drops too. However most vitamin D3 supplements are made from the fat of lamb’s wool, which means they’re unsuitable for vegans. The good news is that vegan vitamin D3 supplements sourced from lichen are now more widely available.
You have to take a lot of care with your health if you’re pregnant or are planning to become pregnant and living with diabetes – plus if you develop gestational diabetes while you’re expecting – but the results of all that effort are worth it. Looking after your lifestyle and making the most of the support offered by your GP and diabetes care team can help make sure you, your pregnancy and your baby are healthy. To find out more about a wide range of health conditions, visit our pharmacy health library.



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(vii) Evans JL, Goldfine ID. Alpha-lipoic acid: a multifunctional antioxidant that improves insulin sensitivity in patients with type 2 diabetes. Diabetes Technol ther. Autumn 2000;2(3):401-13. Available online:
(viii) Elamin. A, Tuvemo. T. Magnesium and insulin-dependent diabetes mellitus. Diabetes Res Clin Pract. 1990;10:203-209. available online: Barbagallow M, Dominguez LJ. Magnesium and type 2 diabetes. World J Diabetes 2015 Aug 25; 6(10):1152-57. Available online:
(ix) Song. Y, He. K, Levitan. EB. Effects of oral magnesium supplementation on glycaemic control in Type 2 diabetes: a meta-analysis of randomized double-blind controlled trials. Diabet Med. 2006;23:1050-1056. Available online:
(x) Razavi M et al. The effects of vitamin D and omega-3 fatty acids co-supplementation on biomarkers of inflammation, oxidative stress and pregnancy outcomes in patients with gestational diabetes. Nutr Metab (Lond). 2017; 14:80 Available online:
(xi) Berridge MJ. Vitamin D deficiency and diabetes. Biochem J. 2017 Mar 24;474(8):1321-1322. Available online:
(xii) Zhang C et al. Maternal Plasma 25-Hydroxyvitamin D Concentrations and the Risk for Gestational Diabetes Mellitus. PLoS One. 2008; 3(11): e3753. Available online:
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Disclaimer: The information presented by Nature's Best is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. Self-treatment is not recommended for life-threatening conditions that require medical treatment under a doctor's care. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications.

Our Author - Christine Morgan


Christine Morgan has been a freelance health and wellbeing journalist for almost 20 years, having written for numerous publications including the Daily Mirror, S Magazine, Top Sante, Healthy, Woman & Home, Zest, Allergy, Healthy Times and Pregnancy & Birth; she has also edited several titles such as Women’ Health, Shine’s Real Health & Beauty and All About Health.

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