Using insulin in pregnancy with type 1/2 diabetes

The treatment you were using to manage diabetes before you became pregnant may change during pregnancy. Your healthcare team may recommend that you start taking insulin, or change your dose.

On this page

Diabetes medication in pregnancy

How does insulin work?

Insulin requirements in pregnancy

If you are new to insulin 

Insulin pump therapy

Hyperglycaemia

Hypoglycaemia

Illness and insulin

Diabetes medication in pregnancy

Your healthcare team will talk to you about any diabetes medications you are taking. They may advise you to change them during pregnancy.

If you are taking tablets, your team may recommend that you switch to insulin injections instead. Or you might be offered metformin tablets as well as, or instead of, insulin injections.  

If you take insulin, you may be able to carry on as before, or you may be advised to change to a different insulin. Your care team will talk with you about this.

If you take any other medications – for example for high blood pressure or cholesterol – these may need to be changed to keep you and your baby safe. Your healthcare team will review all your medications to make sure they’re suitable for pregnancy.

How does insulin work?

Insulin is a type of hormone that helps to control your blood sugar levels. It helps your body to use glucose (sugar) from food for energy.

If you have diabetes, your body struggles to make enough insulin naturally. This means that glucose levels can build up in your blood, which poses risks to your health.

If your body isn’t making enough insulin, you can inject insulin medication, which will help to stabilise your blood sugar levels.

Insulin requirements in pregnancy

Insulin doses change through pregnancy. This is because your insulin resistance is likely to be different as your pregnancy progresses.

If you already take insulin, you might notice a drop in the amount you need in early pregnancy, from around 9 to 16 weeks.

This will often be followed by an increase in insulin requirements as your pregnancy goes on, until about 36 weeks. You may particularly need more insulin before meals, and may be advised to take it at least 15 minutes before eating.

Your healthcare team will help you understand exactly how much insulin you need to take, plus when and how to take it. Try to focus on the fact that these changes are normal during pregnancy, and will help have a healthy pregnancy and baby.  

'Before I got pregnant, I was on around 7 units of insulin for breakfast, but I'd gone up to 40 units. Throughout the pregnancy my insulin requirements were changing constantly. It does seem really tough at the beginning, but you just kind of keep going and get through it.'  
 

Prisha, mum of 2

If you are new to insulin

Insulin only works if it is injected, or delivered by insulin pump. Your healthcare team should explain:

• how to do this
• when to do this  
• how much to take
• how to store your insulin.

If you have any concerns, or are unsure about any of the steps, contact your healthcare team. You can also talk to your GP or call NHS 111.  

Your healthcare team will tell you everything you need to know about injecting insulin. But for general information only, the steps are typically as follows:

1. Always wash and dry your hands before injecting yourself.
2. Choose where you’re going to inject. This will usually be your tummy (under your belly button), your thighs, or your bottom. In late pregnancy, you might find it easier to reach your thighs, or ask your partner to help you inject if you have one. Choose a different spot each time – at least 1cm (half an inch) from where you last jabbed. This will help to ensure that your body can absorb and use the insulin properly.  
3. Attach the needle to your pen as per the instructions that come with it – remove the outer and inner caps – and dial up two units of insulin. Point your pen upwards and press the plunger until a drop of insulin appears at the top. This removes any air from the needle and cartridge.
4. Dial your dose and make sure the skin you’re injecting into is clean (using warm water and soap), and dry.
5. Insert the needle at a right angle (90°). You might prefer to gently pinch the skin before injecting. Press the plunger until the dial goes back to 0.
6. Count to 10 slowly to give the insulin time to enter your body, then remove the needle.
7. Throw away the needle using your needle clipper or sharps bin. Your healthcare team will tell you how to get rid of the bin safely when it’s full.

Insulin pump therapy

If you struggle to keep your blood sugar stable, or hypoglycaemia is making your life difficult, you may be offered an insulin pump. This is more commonly offered before pregnancy, but your healthcare professional may offer it during pregnancy.

The pump is a small device that delivers regular doses of insulin through a fine tube under the skin. If you have a pump, you don’t usually need to give yourself injections, though you will probably need to tell the pump to give you an insulin dose before meals.

Diabetes UK has more about using an insulin pump.

Hyperglycaemia

Hyperglycaemia is when your blood glucose is above your target range. Your healthcare team will explain how to spot and treat hyperglycaemia to reduce complications in pregnancy.

Find out more about hyperglycaemia in pregnancy.  

Hypoglycaemia

Hypoglycaemia is when your blood glucose is below your target range. Pregnancy can make it harder for you to recognise hypoglycaemia, especially in the first trimester.

Hypoglycaemic episodes won’t harm your baby, but may be dangerous for you. Your healthcare team will explain how to monitor your glucose levels to reduce the risk of hypoglycaemia.

They’ll also tell you what you and your friends, family and partner (if you have one) need to know to help treat hypoglycaemia if it happens.  

Find out more about hypoglycaemia in pregnancy.

Illness and insulin

If you have type 1 or 2 diabetes and get ill, your glucose levels may be higher than normal and you may be more resistant to insulin. This means you could be at risk of hyperglycaemia and diabetic ketoacidosis (DKA).  

DKA can be life-threatening. If you have hyperglycaemia or feel unwell, seek urgent medical advice as soon as possible. If you have DKA, it is important you attend the emergency maternity unit or A&E as soon as possible. If your blood sugar is within the target range, but you’re worried about how illness might affect it (for example, morning sickness), speak to your healthcare team. They can advise you on how often to check your blood sugar, and what to do about medication if you don’t feel like eating.

Find out more about hyperglycaemia and diabetic ketoacidosis. Diabetes UK also has more on diabetes and feeling ill.  

Learn more about managing type 1 and 2 diabetes in pregnancy.