Using insulin in pregnancy with type 1/2 diabetes

The treatment you were using to manage your diabetes before you became pregnant may change during pregnancy. If you were using tablets, you may have to start using insulin.

Your healthcare team will talk to you about your diabetes medications and may advise you to change them during pregnancy. If you are taking tablets, you may switch to insulin injections instead. Or you might take 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 another insulin. Your care team will talk with you about this.

Insulin doses change through pregnancy. If you already take insulin, you might notice a drop in the amount of insulin you need in early pregnancy (typically at 8 to 16 weeks). But this will usually be followed by an increased need (especially before meals) as your pregnancy progresses.

The need to change treatment during pregnancy can be unsettling, especially if you’ve been happily using a medication regimen until now. Try to stay positive and focus on the fact that all this change is so you can have a healthy pregnancy and baby.

"Before I got pregnant, I was on around 7 units of insulin for breakfast, but now I'd gone up to 40 units. Throughout the pregnancy my insulin requirements were changing constantly. I think it is one of the hardest things I have had to do, both times, but you just kind of keep going. It’s like running a marathon. You know that you will eventually get to the end, and it does seem really tough at the beginning, but you just get through it.'"

If you are new to insulin

Insulin only works if it is injected. You should be advised:

  • how to do this
  • when to do this
  • how much to take.

Some women find the idea of having an injection overwhelming, especially at first. If you are unsure about any of the steps, contact your healthcare team as soon as possible. You can also talk to your GP. 

Find out more about injecting insulin.

Insulin pump therapy

If you have type 1 diabetes, you may be offered an insulin pump if you are finding it hard to keep your glucose in target range or hypoglycaemia is affecting your day‑to‑day activities. This is more commonly offered before pregnancy but your healthcare professional may offer it during pregnancy. This is a small device that delivers a steady flow of insulin through a fine tube inserted under the skin. If you have a pump, you don’t need to give yourself injections.

Diabetes UK has more information about using an insulin pump.


Hyperglycaemia is when your glucose is too high. It's important to be able to recognise and treat hyperglycaemia to minimise complications in pregnancy.

Find out more about hyperglycaemia in pregnancy


Pregnancy can make it harder for you to recognise hypoglycaemia, especially in the first trimester.

It’s important to know how you can try to limit hypoglycaemic episodes and how to cope with them during your pregnancy. But try not to get too anxious. They won’t harm your baby.

Find out more about hypoglycaemia in pregnancy

Illness and insulin

If you have type 1 or 2 diabetes and get ill, more glucose is released into your bloodstream and your body becomes resistant to insulin. You are at increased risk of hyperglycaemia and diabetic ketoacidosis (DKA) if you are unwell. This is particularly problematic during pregnancy.

Make sure you have a written copy of sick day rules and that you contact your healthcare team straight away if you are unwell or have ketones. Here are some tips:

  • Keep taking your insulin, even if you don't feel like eating.
  • Check your glucose levels at least every 2 to 4 hours.
  • Stay hydrated by having plenty of drinks and try to eat little and often.
  • If ketones are present, contact your diabetes team.
  • Keep eating or drinking. If you can’t keep food down, try snacks or drinks with carbohydrates to give you energy. Try to sip sugary drinks (such as fruit juice or non-diet cola or lemonade) or suck on glucose tablets or sweets like jellybeans. Letting fizzy drinks go flat may help keep them down. If you're vomiting, or not able to keep fluids down, get medical help as soon as possible.

Don’t be afraid to ask your healthcare team If there is anything that you are unsure about. Diabetes UK also has more information about diabetes and feeling ill.


NICE (2015). Diabetes in pregnancy: management from preconception to the postnatal period. National Institute for health and care excellence

NHS Choices. Hyperglycaemia. (Page last reviewed: 08/08/2018 Next review due: 08/08/2021)

NHS Choices. Diabetes in pregnancy. (Page last reviewed: 12/04/2018 Next review due: 12/04/2021)

Review dates
Reviewed: 03 August 2020
Next review: 03 August 2023

This content is currently being reviewed by our team. Updated information will be coming soon.