Infections during pregnancy

You may be more susceptible to urine infection in pregnancy, as well as other issues including kidney problems, sexually transmitted infections and colds and flu.

Here we discuss why and what to do. The immune system can be less effective when you are pregnant, possibly to prevent women rejecting their babies. This may make women more susceptible to illnesses including urine and gum infections, infectious diseases, cold and flu during pregnancy, sepsis, whooping cough and sexually transmitted infections. If in doubt about pregnancy symptoms or infections, always consult your midwife or GP.

Urine infection in pregnancy

Urine infections are more common when you are pregnant because tissue relaxation may prevent your bladder from completely emptying, and the urine left behind can become infected. You may also be more susceptible to cystitis (an infection of the bladder that makes passing urine painful, often with a burning sensation). Sometimes infections can back-track to the kidneys, causing pain and nausea.

Gum infections

You may get a gum infection (gingivitis) when you are pregnant, as the gums tend to swell when you are pregnant so that brushing your teeth causes bleeding more readily. Use a soft brush, and speak to your dentist if you are concerned.

Infectious diseases

Some infections can cause problems with the development of the baby, particularly in early pregnancy. These include German Measles (rubella) and chickenpox.

If you are worried about exposure to German Measles or chickenpox, discuss your immunity with your midwife. If you have any symptoms of chickenpox, seek medical help immediately, as you may need an antiviral drug. 

Colds and flu during pregnancy

Flu can be serious in pregnancy and pregnant women are advised to have the seasonal flu vaccine. If you have a cold or flu, get plenty of rest and fluids. Lower your temperature with cold flannels, and with paracetamol, as long as you do not exceed the stated dose over 24 hours.

Some cold and flu preparations contain other drugs, so check with the pharmacist that they are sutiable for use when you are pregnant. 


Sepsis is an illness that can develop in some pregnant women, as well as in women who have recently had a baby or babies. Sepsis that occurs when you are pregnant is called maternal sepsis. Sometimes called blood poisoning, sepsis is the body’s inflammatory response to infection, but it can overload the body’s ability to cope. Read more in our article here.

Whooping cough

The government now recommends a whooping cough vaccination for women between 28 and 38 weeks of pregnancy. This can help help protect them and their baby from serious disease as protective antibodies are passed from mum to their unborn baby. Newborns are vaccinated at two, three and four months of age. Whooping cough can infect anyone, but it is babies during their first few months of life who are most vulnerable. The vaccination was first introduced as a temporary measure in 2012.

Sexually transmitted infections

Sexually transmitted infections may include HIV, Hepatitis B and C and genital herpes. Sexually transmitted infections can affect the health of you and your baby but may have no symptoms. If there is a chance you might be infected you should see your doctor or midwife. Alternatively, you could visit the nearest genito-urinary medicine (GUM) clinic or sexual health clinic (where your confidentiality is guaranteed).

Page last updated: 15 July 2014

Further information

NCT's helpline offers practical and emotional support with all aspects of being pregnant, birth and early parenthood: 0300 330 0700. We also offer antenatal courses which are a great way to find out more about birth, labour and life with a new baby.

More information on infections, including sexually transmitted infections, whooping cough and blood poisoning can be found on NHS Choices. There is also an A-Z of common health problems which lists several common infections, and you can search for your nearest sexual health clinic.