Intrauterine infection (chorioamnionitis)

An intrauterine infection is an infection inside your uterus (womb).

During pregnancy, an intrauterine infection is called an 'intra-amniotic infection' or chorioamnionitis.

The infection may occur in your:

• placenta
• amniotic fluid (fluid surrounding your baby)
• amniotic membrane (thin layer of tissue surrounding your baby)

An intrauterine infection can also develop after your baby is born. Postpartum endometritis is an infection of your endometrium, which is the lining of your uterus.

Symptoms of an intrauterine infection include:

• fever (a temperature of 38°C or higher), especially after your waters break or during labour
• pain in your uterus
• vaginal discharge with an unpleasant smell or unusual colour

An intrauterine infection may start with mild symptoms, but it can get worse quickly.

An intrauterine infection can cause complications for you and your baby.

Having an intrauterine infection during pregnancy increases your risk of:

• postpartum haemorrhage (significant bleeding after birth)
• other infections such as endometritis or a blood infection
• needing a caesarean birth (C-section)
• blood clots

Having an intrauterine infection during pregnancy increases your baby's chance of:

• being born prematurely (before 37 weeks of pregnancy)
• having a very low Apgar score (a test of your baby's health after birth)
• getting infections such as pneumonia or meningitis
• having cerebral palsy

Intrauterine infections are usually caused by bacteria from your vagina moving into your uterus. This is most likely to happen after your waters break because the torn amniotic sac allows bacteria to enter your uterus.

Bacteria can also get into your uterus during a procedure such as amniocentesis. This is a test used to see if your baby has a genetic condition.

Bacteria can sometimes spread from your blood to your uterus through the placenta, however this is rare.

Types of bacteria that can cause an intrauterine infection include:

• group B streptococcus
• Escherichia coli
• Listeria

You have a higher risk of getting an intrauterine infection if:

• you have a prelabour rupture of membranes (a long time between your waters breaking and your baby being born)
• you go into labour early
• your doctor or midwife performs repeated vaginal examinations after your waters have broken
• you have bacteria in your vagina, such as group B streptococcus or bacterial vaginosis

You should see your doctor or midwife immediately if you have any symptoms of an intrauterine infection, including:

• a fever
• pain in your uterus
• unusual vaginal discharge

Contact your midwife, doctor or maternity care provider straight away if you think your waters have broken. They will examine you to check that you and your baby are well.

Your doctor may diagnose an intrauterine infection based on your symptoms.

Your doctor might also recommend further tests to detect what type of bacteria is causing your infection, such as a:

• blood tests
• vaginal swab
• placenta test, once your baby is born

It's very important to treat an intrauterine infection quickly.

Medicines for an intrauterine infection

An intrauterine infection is treated with antibiotics. If your doctor thinks you have an intrauterine infection, they do not have to wait for the results of your tests to start antibiotic treatment.

You may receive 2 or 3 different types of antibiotics.

You may also receive:

• fluids through an intravenous cannula (IV)
• blood thinning medicine to prevent blood clots
• paracetamol to lower your fever

After your baby is born, you may need to continue antibiotic treatment for up to 24 hours. Your baby will be closely monitored in hospital and might need antibiotics too.

Other treatments

You may need to be admitted to hospital. If you are very unwell with an intrauterine infection, you may need specialised care in an intensive care unit (ICU).

Your baby might need to be born prematurely. Your doctor or midwife will talk with you about induction of labour or having an emergency caesarean.

If your waters break early, ttaking antibiotics can help prevent an intrauterine infection. Your doctor may prescribe you antibiotics for 7 to 10 days.

If your waters break at full term before you go into labour, induction of labour can help prevent an intrauterine infection. Antibiotics may also help prevent infection, especially if you have group B streptococcus in your vagina.

If your waters have broken, it's also important to:

• use pads instead of tampons
• avoid sexual intercourse
• avoid swimming

Having an intrauterine infection during pregnancy doesn't always affect your baby's health. Prompt treatment with antibiotics can help to lower the chance of the infection affecting your baby.

Your baby may develop an infection. If your baby has a high risk of developing an infection, they might be given preventive antibiotics, even if they seem healthy.

If you get an intrauterine infection before you reach full term, your baby may need to be born early. Most premature babies don't have any long-term health complications. Some babies born prematurely can have problems with:

• breathing
• eating
• growing

If you have an intrauterine infection during pregnancy you may be advised to give birth early. Your doctor will talk to you about having an induced labour or an emergency caesarean. The safest option for you will depend on your circumstances.

Contact your doctor or midwife immediately if you think you may have an intrauterine infection.

Visit the Sydney Children's Health Network for information on the growth and development of premature babies.

Read more about the use of antibiotics during pregnancy on the Royal Women's Hospital page.