Infections in pregnancy

Getting an infection in pregnancy is not likely to harm your baby. But it is important to do what you can to avoid them.

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 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 

You are at higher risk of getting seriously ill from coronavirus (Covid-19) during pregnancy, especially if you are more than 28 weeks pregnant.  

Other 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.

Covid-19 vaccine 

There is no evidence that the COVID-19 vaccine causes miscarriage or affects how your baby develops in pregnancy. 

It is strongly recommended that you get vaccinated against COVID-19 to protect you and your baby. The antibodies your body produces in response to the vaccine can also give your baby protection against COVID-19.

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

Find out more about coronavirus and pregnancy.  


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 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: 

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.

Smoked fish and listeria

Due to a listeria outbreak linked to smoked fish, people at higher risk of serious infection (including pregnant people) should only eat smoked fish products that have been thoroughly cooked. When cooking smoked fish products at home, make sure they are steaming hot all the way through.

Smoked fish includes salmon, mackerel, whitefish and trout. 

Find out more from the Food Standards Agency.

Rubella (German measles)  

Rubella is a rare illness caused by a virus, which spreads in coughs and sneezes. The main symptom of rubella is a spotty rash that appears red or pink on white skin. It may be harder to see on black or brown skin but will feel rough or bumpy. Other symptoms may include: 

  • aching fingers, wrists or knees 
  • high temperature 
  • coughs 
  • sneezing and a runny nose 
  • headaches 
  • sore throat 
  • sore, red eyes.

Contact your GP or midwife as soon as you can, if you are pregnant and have a new rash, or have come into contact with someone with rubella.  

While rubella is very rare in pregnancy, it can cause serious harm to your baby if you get it before week 20 of your pregnancy. Sadly, rubella before this time can cause: 

  • miscarriage 
  • problems after your baby is born, such as problems with their sight, hearing, heart or brain
  • There is no known risk to your baby after 20 weeks of pregnancy.

You are protected against rubella if you had 2 MMR vaccinations as a child. MMR jabs protect against measles, mumps and rubella. 

Check with your GP if you are not sure if you have been vaccinated or see if you can get your health records to check for previous vaccinations.  

If you need the MMR vaccine, you should get it before trying for a baby and wait for 1 month before trying, after having it.   

Try not to worry if you were vaccinated shortly before you got pregnant or if you did not realise you were pregnant. This advice is given as a precaution. There have been no reported cases of the vaccine affecting a baby. 

Sexually transmitted infections  

Sexually transmitted infections (STIs) are passed on through sex or genital contact. They are also sometimes known as sexually transmitted diseases (STDs). STIs often have no symptoms, so you may not know if you have one. However, symptoms can include: 

If they are not treated, some STIs can cause: 

Some STIs can also cause long-term health problems if they are passed to your baby, such as infections and blindness. 

It is a good idea to get tested if you have a new sexual partner, you or your partner have symptoms or you are worried about STIs. The best places to go are sexual health or genito-urinary medicine (GUM) clinics, or your GP. If you are under 25 you can also visit a Brook centre. You can order some STI tests online after completing an online assessment. The tests are posted to your home in discreet packaging and, if any of your results are positive, you will be offered a face to face appointment with a sexual health professional. 

All information given will be kept confidential, and tests are only done with your permission. 

You can find details of your local sexual health clinics by contacting the National Sexual Health Line on 0300 123 7123 or Sexual Health Information Scotland on 0800 22 44 88. If you are in England, you can also use the NHS clinic finder.  

If you have a partner, ask them to have a sexual health check-up too. 

Find out more about getting pregnant and sexually transmitted infections (STIs)


Shingles is an infection caused by the chickenpox virus. It happens when the chickenpox virus that is dormant (inactive) in your body, usually from childhood, is triggered. This can happen if your immune system is weakened or if you have an underlying health condition.

Symptoms of shingles include: 

  • pain or tingling on the skin 
  • a headache or feeling unwell 
  • a blotchy rash on one side of your body that can look red on white skin but is harder to see on brown or black skin 
  • itchy blisters that ooze fluid, then dry out and scab.

The rash tends to appear on the chest and tummy, but can also appear elsewhere, such as the face, eyes and genitals. 

You cannot catch shingles from someone with chickenpox or shingles. But you can catch chickenpox from someone with shingles, if you have not had chickenpox before. If you haven‘t had chickenpox before, or you‘ are not sure whether you have, you should stay away from anyone with shingles.  

If you get shingles when you’re pregnant there’s no risk to your pregnancy or your baby. But you should contact your midwife or GP because you may need treatment. 

Slapped cheek syndrome 

Slapped cheek syndrome is caused by a virus called parvovirus B19. It gets its name from the face rash that it causes.  Just over half of adults are already immune to the infection because they had it in childhood.

Symptoms may include: 

  • a high temperature  
  • a runny nose or sore throat 
  • headache 
  • in children, a bright red rash on one or both cheeks that looks red on white skin but is harder to see on black or brown skin 
  • a spotty rash on your chest, arms and legs that can be raised and itchy and is harder to see on black or brown skin 
  • in adults, joint pain and stiffness in the hands, wrists, knees and ankles that may last for some weeks.

Most pregnant people who get slapped cheek syndrome have healthy babies but getting slapped cheek syndrome during the first 20 weeks of pregnancy can increase the risk of miscarriage. If you get it between weeks 9 to 20, there is also a small risk that your baby will develop foetal hydrops. This is a condition that can cause heart failure, anaemia and sometimes death, if untreated.

Slapped cheek syndrome during pregnancy has not been shown to cause birth defects or development problems later in childhood. 

See your GP or midwife as soon as possible if you are pregnant and think you have come into contact with someone with slapped cheek syndrome. You should do this whether you get a rash or not.

Your doctor will do a blood test to check whether you have parvovirus B19. If the test confirms you have it, your doctor will refer you to a specialist in fetal medicine, so that they can monitor your baby with extra ultrasound scans throughout your pregnancy. 


Most cases of toxoplasmosis are from eating contaminated food. But there are other ways you can catch the infection, such as touching contaminated cat poo,for example, by changing the litter box and then touching food. 

Most people with toxoplasmosis do not show any symptoms. However, some people may have: 

  • high temperature 
  • aching muscles 
  • tiredness 
  • feeling sick 
  • sore throat 
  • swollen glands. 

If you get toxoplasmosis for the first time while you are pregnant, or a few weeks before you get pregnant, there is a very small risk the infection could spread to your baby (congenital toxoplasmosis).  

There is a small risk the infection could cause: 

1 in 10,000 babies are born with congenital toxoplasmosis in the UK.

The risk to your baby depends on when you were infected:

  • If you are infected in early pregnancy, it is less likely to spread to your baby. But if it does it can cause more serious problems.  
  • If you are infected later in pregnancy, it is more likely to spread to your baby. However, any problems may be less severe. 

There are things you can do to prevent toxoplasmosis and it can be treated. Find out more about toxoplasmosis in pregnancy

Whooping cough 

Whooping cough is a bacterial infection of the lungs and breathing tubes. It is highly contagious. This means you can catch it easily and pass it on easily. Adults tend to have less severe infections than children. Symptoms may include: 

  • symptoms similar to a cold 
  • bouts of coughing that are worse at night 
  • redness in the face 
  • bringing up a thick mucus that can make you sick (vomit) 
  • coughing that causes nosebleeds, sore ribs or a hernia. 

Babies that are too young to be vaccinated are at risk of getting whooping cough. If they do catch it, it can be very serious. Most will need to be treated in hospital. Sadly, some babies die from the infection.

That is why experts recommend having the whooping cough vaccine during pregnancy. The immunity you get from the vaccine passes through the placenta to your unborn baby. It will help protect your baby from getting whooping cough until they are vaccinated at 2 months old. 

Find out more about vaccinations in pregnancy and whooping cough vaccination safety.  

Zika virus 

Zika virus disease is mainly spread by mosquitoes. It can also be passed on through sex, although the risk is very low. The Zika virus is found in parts of: 

  • South and Central America 
  • the Caribbean 
  • the Pacific islands 
  • Africa 
  • Asia.  

The risk of getting Zika in the UK is extremely low because the types of mosquito that carry Zika are not found here.  

Most people have few or no symptoms with Zika virus, or symptoms may be mild. They may include: 

If you catch Zika in pregnancy, it can harm your unborn baby, causing: 

  • an abnormally small head (microcephaly)  
  • abnormal brain development 
  • Guillain-Barré syndrome, a rare condition that affects the nervous system. 

You can try to avoid getting the Zika virus by: 

  • not going to areas at risk of Zika virus transmission until after your pregnancy. Visit Gov.UK for up-to-date advice. 
  • talking to your GP, midwife or doctor if you must travel. They may be able to give you more advice about which insect repellents to use and how to protect your body with clothing. 
  • making sure you use condoms during sex throughout your pregnancy.

See your doctor or midwife if you are pregnant and have recently travelled to a country with a Zika virus risk, or if you get pregnant within 3 months of returning to the UK. They can discuss the risks with you and arrange some tests if needed.  

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Review dates
Reviewed: 08 June 2023
Next review: 08 June 2026