How pregnancy can affect you if you have diabetes

Diabetes and pregnancy

If you have diabetes and are pregnant, it is important to take extra care of your health. This section explains some of the possible complications and gives you practical guidance on how to cope.

Your diabetes and pregnancy team monitors you closely throughout your pregnancy. We can help if you have any questions or concerns.

Low blood sugar (hypoglycaemia)

Your insulin needs change in early pregnancy and this can lead to severe hypos (episodes of low blood sugar). 

Many people’s early warning signs for hypos, such as feeling shaky or sweating, change or disappear completely in pregnancy. This means that hypos often happen fast and without enough warning for you to treat the early symptoms.

Many people’s early warning signs for hypos, such as feeling shaky or sweating, change or disappear completely in pregnancy. This means that hypos often happen fast and without enough warning for you to treat the early symptoms.

GlucaGen® HypoKit®

We invite your partner or family to meet with your diabetes specialist nurse for an information session. This covers when and how to treat hypos, including using glucagon in an emergency.

A GlucaGen Hypokit is a prescription emergency kit to treat very low blood sugar (severe hypoglycaemia). It contains an injection of a hormone called glucagon, which can treat a severe hypo in someone who has lost consciousness.

Glucagon helps your body to release sugar (glucose) stored in your liver. This raises your blood sugar level quickly.

Actions to cope with low blood sugar (hypoglycaemia)

Do

  • carry treatment for a hypo, such as glucose tablets, jelly babies or glucose gel and a carbohydrate snack like dry biscuits, with you at all times
  • check that your GlucaGen HypoKit is in date and ask your GP for a prescription, if needed

Viral infections

Just as before pregnancy, illnesses such as colds and other viral infections can make your blood sugar levels rise. When you are pregnant, you need to be particularly careful if this happens.

It is recommended that everyone who is pregnant in the UK has the flu vaccine (flu jab) before the flu season starts.

If you are pregnant and have diabetes, you are not more at risk of getting coronavirus (COVID-19). However, if you do get COVID-19, you have a higher chance of complications and may find it hard to manage your diabetes. If you get COVID-19 late in your pregnancy, your baby could also be at risk.

It is important to tell your diabetes and pregnancy team if you have symptoms of COVID-19. To protect yourself and your baby, it is strongly recommended that you get vaccinated against COVID-19.

You can find the latest information about COVID-19 in pregnancy from the Royal College of Obstetricians and Gynaecologists.

Actions to cope with viral infections

Do

  • check your blood sugar levels more often when you are unwell
  • if you have type 1 diabetes, check your blood or urine for ketones (harmful substances that build up in the body if it starts to run out of insulin)
  • take your insulin or tablets (you may need to increase your insulin dose when you are unwell to control your blood sugar levels and prevent ketones)
  • get medical advice if your blood test result for ketones is more than 1.5mmol/L or your urine ketone level is higher than 1+
  • get medical advice if you are being sick (vomiting) or cannot eat or drink
  • get medical advice if you are worried about high blood sugar levels
  • see your GP to find the cause of the illness

Call 999 or go to A&E now if:

you are being sick (vomiting) so much that you cannot keep down food or fluids

Diabetic ketoacidosis (DKA) and high blood sugar

If your body cells cannot use sugar (glucose) for energy, they break down fats instead to make chemicals called ketones. You can test the level of ketones in your blood or urine.

High blood sugar and ketones can lead to a serious condition called diabetic ketoacidosis (DKA). This needs to be treated in hospital. DKA mainly affects people with type 1 diabetes, but can sometimes happen to people with type 2 diabetes.

You can get DKA if you:

  • are unwell
  • forget to take your insulin
  • do not take enough insulin

To prevent DKA, it is important to test your blood sugar regularly and increase your insulin doses when you are unwell. 

If you are unwell, you need to monitor the level of ketones in your body. You can test your blood or urine for ketones and get a prescription for ketone testing strips.

Diabetes complications

Pregnancy can make you more likely to get complications of long-term diabetes, such as kidney and eye damage (diabetic retinopathy). Being pregnant can also make any diabetes complications that you already have worse.

Before you are pregnant, your doctor arranges for you to have your eyes, kidneys and nerves tested. The tests show if you have any diabetes complications.

If you do have diabetes complications, we need to monitor them closely throughout your pregnancy. In most cases, any worsening (deterioration) of your eyes or kidneys during pregnancy resolves after your baby is born.

If your diabetes complications are advanced, you need an individual assessment. It is important to check if it is safe for you to carry a child. Pregnancy puts extra stress on your body.

Morning sickness

Especially during the first 12 weeks of pregnancy, some people feel sick first thing in the morning or in the evening. Others feel sick all day and may vomit (be sick).

Actions to cope with morning sickness

Do

  • keep drinking fluids. If you do not feel like eating solid food, sip on drinks like flat lemonade, diluted cordial or fruit juice to avoid hypos
  • eat small, frequent meals and talk to your diabetes team about adjusting your insulin doses
  • avoid strong food smells and rich, fatty foods
  • snack on something like dry toast or plain dry biscuits or crackers before getting out of bed, if mornings are a problem
  • have salty foods if they help. Try small amounts of potato crisps or salty crackers
  • try ginger tea, as some people find that it helps to reduce nausea (feeling sick) and vomiting (being sick)
  • always take your insulin, but you may need to lower your dose
  • take anti-sickness medicine when your symptoms are severe if your doctor has prescribed this

Pre-eclampsia

Pre-eclampsia is a serious complication of pregnancy. We diagnose this condition if you have:

Pre-eclampsia happens more often in people with diabetes and can cause premature birth.

If you get pre-eclampsia, it may be dangerous for you and your baby. At each appointment, your doctor or team checks your blood pressure and urine, and looks for swelling in your face, hands and feet.

Resource number: 1702/VER4
Last reviewed: September 2022
Next review due: September 2025

A list of sources is available on request.

Contact us

Please contact us if you have any questions or would like to speak with the diabetes antenatal team.

Phone: 020 7188 1993, Monday to Friday, 9am to 5pm

If we cannot answer your call, please leave a voicemail. We call you back within 1 working day.

Email: [email protected]

We respond to your email within 1 working day.

Address: Diabetes and endocrine day centre, 3rd floor, Lambeth Wing, St Thomas' Hospital, Westminster Bridge Road, London SE1 7EH

Help to give up smoking

If you need help to give up smoking, you can contact our stop smoking service or the free National Smokefree Helpline (England only).

Hospital team: 020 7188 0995

National Smokefree Helpline: 0300 123 1044 (Monday to Friday, 9am to 8pm, Saturday and Sunday, 11am to 4pm)

Pharmacy medicines helpline

If you have any questions or concerns about your diabetes medicines, please speak to the staff caring for you.

You can also contact our pharmacy medicines helpline.

Phone: 020 7188 8748, Monday to Friday, 9am to 5pm

Email: [email protected]

Do you have any comments or concerns about your care?

Contact our Patient Advice and Liaison Service (PALS)

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