Chorioamnionitis: causes, symptoms and treatment

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What is chorioamnionitis?

How common is chorioamnionitis?

What causes chorioamnionitis?

How can I reduce my risk of chorioamnionitis?

What are the symptoms of chorioamnionitis?

What problems can chorioamnionitis cause?

How is chorioamnionitis treated?

What will happen to my baby after they are born?

What is chorioamnionitis?

Chorioamnionitis is inflammation of the membranes around the baby in the womb, sometimes with infection too. It’s also sometimes called intrauterine infection. It can happen during pregnancy, labour, or following birth.

How common is chorioamnionitis?

Chorioamnionitis affects about 4 in 100 full-term deliveries (after 37 weeks of pregnancy). It is more common in preterm births (babies born before 37 weeks of pregnancy). Some studies suggest that it affects up to 70 in 100 premature births.

What causes chorioamnionitis?

The most common cause of chorioamnionitis is bacteria moving up to the womb from the vagina or cervix.  

Bacteria can also reach the placenta in your blood.

Less commonly, you can get an infection after a procedure such as an amniocentesis or fetoscopy (where a small camera is used to examine your baby inside the womb). Your doctor needs your permission (consent) to do this and should explain the risks and benefits before you decide.  

Sometimes, inflammation of the membranes around the baby can happen without any sign of infection.

Some things increase the risk of chorioamnionitis:

• having chorioamnionitis in a previous pregnancy
• smoking and drinking alcohol in pregnancy
• Group B streptococcus infection in pregnancy
• bacterial vaginosis
• sexually transmitted infections
• getting pregnant when you have an intrauterine device (coil)
• getting pregnant as a result of  IVF
• having a balloon catheter to help your cervix ripen faster or induce labour.

Complications during labour can also increase the risk of infection in your womb. For example, the risk goes up if:

• you give birth prematurely
• you need several internal exams during labour, especially after your membranes have ruptured
• you have a weak or short cervix
• you have a long labour, or there is a long time between your membranes rupturing and your baby being born 
• your baby poos (passes meconium) during labour, which goes into the amniotic fluid.

How can I reduce my risk of chorioamnionitis?

There are some things you can do to try to avoid an intrauterine infection:

• Don’t smoke or drink alcohol.
• Speak to a GP or your midwife if your vaginal discharge changes.
• Go to all your antenatal care appointments.
• If you have had bacterial vaginosis in the past, use water and plain soap to wash your genital area and have showers rather than baths. 
• Contact your doctor or midwife if you have any symptoms of a urinary tract infection (UTI).

You might do all you can to avoid an infection during pregnancy but still get one. Getting an infection during pregnancy is not your fault.

Your doctor may offer you antibiotic tablets if your waters break early (before 37 weeks). This can reduce the risk of infection and help your pregnancy to carry on.

What are the symptoms of chorioamnionitis?

Sometimes there are no symptoms. Your midwife or doctor may only suspect chorioamnionitis if your waters break early.

If you do have symptoms, they can include:

• high temperature  
• tender tummy in your womb area
• your heart beating fast
• your baby’s heart beating fast
• bad smelling vaginal discharge.

It’s normal to have more vaginal discharge in pregnancy. But call your midwife or doctor if you have vaginal discharge and:  

• it smells bad or strange  
• it is green or yellow
• you feel itchy or sore around your vagina
• it hurts when you wee.

These can all be signs of an infection in your vagina, which could lead to chorioamnionitis. 

What problems can chorioamnionitis cause?

Chorioamnionitis can lead to complications:

• preterm pre-labour rupture of the membranes (waters breaking early)  
• premature birth
• stillbirth
• infections, including sepsis, in you or your baby  
• heavy bleeding after birth
• lung and breathing problems in your baby
• problems with how your baby’s brain develops.  

This sounds scary but remember your midwife or doctor will check for any signs of chorioamnionitis if you have any worrying symptoms during pregnancy.  

Tell your midwife or doctor if you are worried at any point. Do not think that you’re wasting their time, even if you’ve talked about it before. Trust your instincts if you feel something isn't right. 

How is chorioamnionitis treated?

It is not always easy to spot an infection because there may not be any clear symptoms. If your healthcare team thinks you have an infection, they will offer you a blood test or a vaginal swab test.

Chorioamnionitis is treated with antibiotics. You will probably need to take them until your baby is born.

If you have not yet gone into labour, your healthcare team may talk to you about whether it would be safest to have your baby early. Read more about having your labour started artificially (induction of labour). 

What will happen to my baby after they are born?

If you have chorioamnionitis, there is a risk that your baby may have an infection too. Your healthcare team will assess your baby’s health as soon as they are born, and do some tests, including blood tests. They will probably recommend that your baby is treated with antibiotics. They will talk to you about your baby’s health, the treatment options, and the benefits and risks of these options.  

If you want to, you can usually still breastfeed your baby if they have – or are at risk of – an infection. Your healthcare team can support you to do this, including helping you express breast milk if your baby is unable to breastfeed.

Getting support  

Having complications during pregnancy or labour can be tough to cope with. But your healthcare team is there to help you.  

You can also talk to a Tommy’s midwife by calling our free helpline (Monday-Friday, 9am-5pm) on 0800 014 7800 or you can email [email protected]. We also have a Black and Black-Mixed Heritage Helpline – you can book a call with one of our midwives.