Infections in pregnancy

Infections are caused by bacteria or viruses. Bacterial infections, such as whooping cough, are usually treated with antibiotics. Viral infections such as chickenpox, can’t be treated with antibiotics, but there are ways to manage their symptoms.  

Here are some simple steps you can take to reduce your risk of getting an infection in pregnancy. 

• Have all the vaccinations you are offered in pregnancy.
• Wash your hands thoroughly, with soap and water, especially after going to the toilet, changing nappies, and before preparing food or eating and drinking.
• Try to avoid people who are unwell.
• Do not change or touch dirty cat litter or soil that might be contaminated with cat poo.
• Make sure all your meals are properly cooked, especially meat and shellfish.
• Avoid unpasteurised milk and foods made with it.
• Get tested for sexually transmitted infections (STIs) and use a condom if you or your partner are at risk from STIs.
• Avoid sharing food, cutlery or drinking glasses with young children. Avoid sharing a toothbrush with them or kissing them on the face.
• Contact your GP, doctor or midwife if you have been in contact with someone with an infection, even if you do not have any symptoms.
• Contact your GP, doctor or midwife straight away if you have any flu-like symptoms or are worried about another symptom.
• If your food is safe to reheat, make sure it is steaming hot all the way through. You should only reheat food once. Find out more about foods to avoid in pregnancy and tips for food safety.   
• If possible, delay conception within 3 months of returning from a country or area where you could catch the Zika virus, and to avoid travelling to these areas until after your pregnancy.
• If you have a pet rodent, such as a gerbil, hamster or chinchilla, ask someone else to clean the cage and care for them.
• Call your midwife, GP or NHS 111 if you develop a rash in pregnancy. 

Below, you will find information about the infections that can cause problems during pregnancy. Knowing the risks and symptoms will help you to protect yourself and your developing baby from infection.  

Chickenpox  

Chickenpox is a common viral infection that causes a rash and itchy spots. Other symptoms of chickenpox include: 

• a high temperature  
• aches and pains, and feeling unwell
• blisters that appear anywhere on the body, which then burst and crust over
• loss of appetite. 

You can catch chickenpox by being near someone who currently has it. You can also catch chickenpox from someone with a virus called shingles if you have not had chickenpox before.

Call your GP or 111 straight away and you have been near someone with chickenpox or shingles and: 

• you have never had chickenpox
• you are not sure if you have had chickenpox
• you develop a rash.  

It is possible to get chickenpox more than once, but it is unusual. Most people will be immune after having chicken pox once. 

Most people get chickenpox during childhood, so it is rare to catch it during pregnancy.  Around 9 in 10 pregnant women and birthing people are already immune to chickenpox infection.  

If you do catch chickenpox when you are pregnant, there is a small risk that you baby will be very ill when they are born. The highest risk is during the last 4 weeks of pregnancy. 

You are at greater risk of complications if you catch chickenpox when you are pregnant if you: 

• smoke cigarettes
• have a lung disease such as bronchitis or emphysema
• are taking steroids or have done so in the last 3 months
• are more than 20 weeks pregnant.

If any of these apply to you, you may need to be referred to hospital. 

Chickenpox can also make you very sick so it is very important to get medical help if you think you may have caught it.   

It is important to call first rather than going to your GP surgery or seeing your midwife. This will help make sure you don’t pass it on if you have it.  

Your GP can organise a blood test to see if you are immune. 8 out of 10 women and birthing people will be immune without realising but if you are not immune to chickenpox you may need treatment.  

Covid 19 

If you’re pregnant, you’re no more likely to get the virus than another healthy adult. However, there is a slightly higher risk of becoming more seriously ill if you do. The overall risk of serious illness is low though and the risk of your baby being harmed if you catch it is also very low.

Things that can put you at higher risk if you are pregnant include if you: 

• have an underlying medical condition (such as diabetes, high blood pressure, heart disease or asthma)
• are overweight
• are aged 35 or over
• are from an ethnic minority group.

If you get COVID-19 late in your pregnancy, your baby may be born prematurely or have a low birthweight. Covid-19 also increases the risk of having a stillbirth but your overall risk of stillbirth is still low.

It is important to tell your midwife if you have symptoms of COVID-19. They can give you advice and support. 

From spring 2025, vaccination against COVID-19 will no longer be offered to pregnant people as the risk of being hospitalised or dying due to COVID-19 in pregnancy is now very small.

Find out more about COVID-19 and pregnancy.  

Cytomegalovirus 

Cytomegalovirus (CMV) is a common virus that is usually harmless but can sometimes cause problems in babies if you catch it during pregnancy. This is known as congenital CMV infection.

Most people with CMV who are pregnant and healthy will have no symptoms. But you may have a mild illness with flu-like symptoms the first time you catch CMV, such as: 

• fever
• sore throat
• aching muscles
• skin rash
• feeling sick
• tiredness (fatigue)
• swollen glands.

Symptoms usually improve within about 3 weeks. 

Call your GP or midwife if you are pregnant and you have any flu-like symptoms. 

Most babies with congenital CMV have no symptoms at birth and no long-term problems. But some babies may go on to develop problems later in life, such as hearing loss and learning difficulties. 

There is no treatment for CMV in pregnancy at the moment but recent studies have shown that antiviral treatments with a drug called valacyclovir may help to reduce the risk of passing it to your baby during pregnancy. Ask your doctor what treatment options may be open to you.  

There are practical ways to reduce your risk of catching CMV in pregnancy, such as washing your hands regularly, avoiding kissing young children on the mouth, washing your hands thoroughly after changing nappies and not placing children’s used dummies or cutlery in your mouth. 

Find out more about cytomegalovirus. 

Hepatitis B 

Hepatitis B is a virus that infects the liver. You can catch the virus by: 

• having sex with an infected person without a condom
• injecting drugs using shared needles
• direct contact with infected blood, for example by sharing a razor or a toothbrush.

Most people either have no symptoms, or have mild symptoms of hepatitis B. These include: 

• a high temperature
• tiredness
• pain in the upper tummy
• feeling or being sick
• patches of raised itchy skin (hives)
• yellowing of the skin and whites of the eyes (jaundice).

If you have hepatitis B in pregnancy the infection could be passed on to your baby during pregnancy or birth. That is why all pregnant people are offered a blood test for hepatitis B as part of their antenatal care.  

If you have the virus, your baby should be given the hepatitis vaccine at birth, again at 4 weeks, and at 12 months old, in addition to their routine vaccines. This is very effective in reducing the risk of them developing the hepatitis B infection. If you had high levels of the virus during your pregnancy, your baby will also need an injection called hepatitis B immunoglobin (HBIG) just after their birth. 

There is also a vaccine for people who may have a higher risk of getting hepatitis B. This includes people who: 

• work in areas that put them at risk of contact with blood or bodily fluids, such as nurses, prison staff, doctors, dentists and people who work in labs
• may have travelled to high-risk countries   
• have a sexual partner with hepatitis B29.

There is no evidence of any risk to you or the baby from having the hepatitis vaccine. Talk to your GP or midwife if you think you are at higher risk or have any other concerns about hepatitis B.  

Hepatitis C 

The hepatitis C virus infects the liver. Most people catch it by: 

• sharing unclean needles, largely to inject recreational drugs
• sharing razors or toothbrushes
• having unprotected sex with an infected person (although this is very rare).  
• If it is not treated, hepatitis C can cause major damage to the liver.

Most people with hepatitis C have no symptoms and will not know they are infected until their liver is badly damaged. However, symptoms may include: 

• flu-like symptoms
• feeling tired
• loss of appetite
• stomach ache
• feeling and being sick. 

It is possible for the hepatitis C infection to pass to your baby during pregnancy, but most babies will not be affected. However, if you have HIV as well as hepatitis C, then it is more likely that your baby will get hepatitis C during pregnancy. 

Your baby can be tested for hepatitis C. Unlike hepatitis B, there is no vaccine that protects against it. If they have the infection, your doctor will refer them for an assessment with a specialist.  

Hepatitis C will not affect your child’s growth or development, but they will need monitoring and treatment in later life to protect their liver from damage. 

Talk to your GP, doctor or midwife if you are worried about hepatitis C.  

Listeriosis 

Listeriosis is a rare infection caused by bacteria called listeria. Most people will not have symptoms, but any symptoms may include: 

• high temperature
• aches and pains
• chills
• feeling or being sick
• diarrhoea.

For most people, the infection goes away on its own within a few days. But even a mild case can cause serious problems if you are pregnant. These include: 

• miscarriage  
• stillbirth
• severe illness in a newborn baby. 

Listeriosis is usually caught from eating and drinking things that may contain listeria bacteria. These include: 

• unpasteurised milk
• dairy products made from unpasteurised milk
• mould-ripened soft cheeses, like camembert and brie
• chilled ready-to-eat-food, like pậté and deli meats
• uncooked smoked fish, such as smoked salmon
• any undercooked foods
• food that is past its use-by-date, even if it looks and smells normal.

Find out more about food and drink to avoid in pregnancy.  

Although less common, you can also catch listeriosis from: 

• someone else who has it. For example, if you eat food they have touched when they have not washed their hands
• close contact with farm animals, especially sheep and cows that are giving birth

There are things you can do to prevent listeriosis, including: 

• washing your hands with soap and water
• washing fruit and vegetables before eating  
• storing ready-to-eat foods away from raw foods and as recommended on the labels
• making sure all hot food is steaming hot all the way through. 

Speak to your GP or midwife straight away if you have any symptoms of listeriosis, or you are worried about something you have eaten or come into contact with. Your GP can arrange a blood test to check for the infection, and prescribe antibiotics to protect you and your baby, if needed.