What is chorioamnionitis?

Chorioamnionitis (chor-y-oh-am-nee-oh-NY-tis) is an infection of the placenta and the amniotic fluid. Only a few women get it, but, it is a common cause of preterm labor and delivery.

What causes chorioamnionitis?

Chorioamnionitis is most often caused by bacteria commonly found in the vagina. It happens more often when the bag of waters (amniotic sac) is broken for a long time before birth. This lets bacteria in the vagina move up into the uterus.

Who is at risk for chorioamnionitis?

You are more likely to have this infection if:

  • Your bag of waters (amniotic sac) breaks long before you actually deliver

  • You have a long labor

  • You have frequent vaginal exams during labor

  • This is your first pregnancy

  • You have a sexually transmitted infection or other vaginal infection

  • You use alcohol or tobacco

  • You have internal fetal monitoring

  • You get epidural anesthesia during labor

  • You have group B strep

What are the symptoms of chorioamnionitis?

Symptoms may be a little different for each person. They may include:

  • Fever

  • Fast heart rate in mother and baby

  • Sore or painful uterus

  • A bad smell from the amniotic fluid

The symptoms of chorioamnionitis can seem like other health problems. Always see your healthcare provider for a diagnosis.

How is chorioamnionitis diagnosed?

Your provider will ask about your past health. He or she will give you a physical exam. He or she may be able to diagnose chorioamnionitis just by your symptoms. You may also need a lab test to check for infection.

Your healthcare provider may suggest a test called amniocentesis, although this test is not routinely done for chorioamnionitis. During this test, your healthcare provider uses a needle to take a small amount of amniotic fluid for testing.

How is chorioamnionitis treated?

Treatment will depend on your symptoms, age, and general health. It will also depend on how severe the condition is.

Antibiotics are used to treat chorioamnionitis as soon as the infection is found. Your healthcare provider may encourage you to deliver your baby early. This can prevent complications for you and your baby. You may need to keep taking antibiotics after your baby is born.

What are possible complications of chorioamnionitis?

Chorioamnionitis can cause a dangerous blood infection in the mother called bacteremia. This can cause the baby to be born early. It can also cause serious complications in the newborn. This includes infection (such as pneumonia or meningitis), brain damage, or death.

What can I do to prevent chorioamnionitis?

If your bag of waters breaks early (premature rupture of membranes), antibiotics lowers the chance of chorioamnionitis. It is also helps to limit the number of vaginal exams before and during labor.

When should I call my healthcare provider?

If your membranes rupture, tell your healthcare provider right away. Other symptoms that call for urgent care include:

  • Fever

  • Fast heart rate

  • Sore or painful uterus

  • Bad-smelling amniotic fluid

Key points about chorioamnionitis

  • Chorioamnionitis is an infection of the placenta and the amniotic fluid. 

  • It happens more often when the amniotic sac is broken for a long time before birth.

  • The major symptom is fever. Other symptoms include a fast heart rate, sore or painful uterus, and a bad smell from the amniotic fluid.

  • Chorioamnionitis can cause complications for the mother and the baby.

  •  You may be given antibiotics if you have premature rupture of the membranes. This can reduce the risk for chorioamnionitis.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

  • Know the reason for your visit and what you want to happen.

  • Before your visit, write down questions you want answered.

  • Bring someone with you to help you ask questions and remember what your provider tells you.

  • At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.

  • Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.

  • Ask if your condition can be treated in other ways.

  • Know why a test or procedure is recommended and what the results could mean.

  • Know what to expect if you do not take the medicine or have the test or procedure.

  • If you have a follow-up appointment, write down the date, time, and purpose for that visit.

  • Know how you can contact your provider if you have questions.

Online Medical Reviewer: Donna Freeborn PhD CNM FNPHeather TrevinoIrina Burd MD PhD

Date Last Reviewed: 3/1/2019

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