Chorioamnionitis

Chorioamnionitis (intra-amniotic infection) is an infection that happens during pregnancy. It gets its name from the two membranes that surround a fetus: the chorion and the amnion.

This infection occurs when bacteria enter any of the membranes or tissues around a fetus. These include:

• Chorion (outer membrane)
• Amnion (inner membrane)
• Placenta
• Amniotic fluid

Treatment usually involves getting antibiotics. In some cases, your pregnancy care provider may deliver your baby early. The infection can lead to life-threatening complications in both you and your baby if it’s left untreated.

Chorioamnionitis occurs in between 2 and 5 out of every 100 births in the U.S.

Symptoms of chorioamnionitis

Symptoms can vary. Some of the most common are:

• Fever
• Rapid heart rate in you or the fetus
• Tender or painful uterus
• Vaginal discharge that has an unpleasant smell or unusual color
• Sweating

Chorioamnionitis causes

A bacterial infection causes chorioamnionitis. The infection can start in your vagina, anus or rectum and spread up to your uterus. It can also begin in your uterus if the amniotic sac ruptures or tears. The bacteria can infect the placenta or the fetus.

Infection can also spread if you have too many vaginal exams after your water breaks or after a procedure like amniocentesis.

The most common bacteria that cause chorioamnionitis are E.coli and group B strep.

Risk factors

Factors that raise your risk include:

• Going into preterm labor
• Your water breaking more than 24 hours before delivery
• Having a long labor
• Having a vaginal infection or a sexually transmitted infection (STI)
• Having group B strep
• Having frequent vaginal exams after your water breaks
• Needing internal fetal monitoring

How to reduce your risk

There are a few things that reduce your risk of chorioamnionitis. These include:

• Taking antibiotics if your water breaks early
• Limiting the number of vaginal exams after your water breaks
• Getting screened for group B strep in your third trimester

If you’re worried about chorioamnionitis, talk to your pregnancy care provider. They can tell you if you’re at risk.

Complications of chorioamnionitis

If you have a serious case of chorioamnionitis, or if it goes untreated, some of the complications are:

• Infection spreading to your pelvic region and abdomen
• Endometritis
• Blood clots in your pelvis or lungs
• Sepsis (a life-threatening blood infection)

Your newborn baby could also have complications, like:

• Sepsis
• Meningitis (brain and spinal cord inflammation)
• Pneumonia (lung infection)

Serious complications are less likely when you get prompt treatment.

How is chorioamnionitis diagnosed?

Your pregnancy care provider diagnoses chorioamnionitis based on your symptoms and a physical exam. They may also:

• Order a blood test and urine test to check for infection or a high white blood cell count
• Take a vaginal culture to look for bacteria
• Take an amniotic fluid sample to test for bacteria
• Use ultrasound to check on the fetus

How is it treated?

If your provider diagnoses chorioamnionitis, they’ll give you antibiotics to treat the infection. These are usually given through an IV (a needle in your vein).

In some cases, providers recommend early delivery. This can prevent more problems for you and your baby.

After birth, your baby may also get antibiotics. Some babies may need oxygen to help them breathe or require extra care in a neonatal intensive care unit (NICU).

When should I see my healthcare provider?

Call your pregnancy care provider if your water breaks. You should also call them if you:

• Have a fever
• Have abdominal or pelvic pain
• Notice a bad smell coming from your vagina

Can a baby survive chorioamnionitis?

Yes, they can. When the infection is caught and treated quickly, most babies make a full recovery. The exact outcome also depends on:

• How far along you are in pregnancy
• How severe the infection is
• If your baby develops complications before treatment