Chorioamnionitis, sometimes called intra-amniotic infection and inflammation, is a serious bacterial infection within the uterus that can affect pregnant women. Women can develop this condition before their water breaks or after they go into labor.
This infection can affect any of the tissues surrounding the fetus, including the following:
- Placenta
- Chorion (outer membrane)
- Amnion (inner membrane)
- Amniotic fluid
In the U.S., the condition affects about 1%-5% of full-term births, but it can affect 40%-70% of preterm births. It is a common cause of premature delivery. Chorioamnionitis can lead to serious infections in both the mother and baby if left untreated.
What Causes Chorioamnionitis?
Chorioamnionitis is caused by bacteria. Usually, these bacteria are from different species, so they’re called polymicrobial bacteria. These bacteria can come from your urinary or gastrointestinal tract or from an outside source.
Common types of bacteria that cause chorioamnionitis include the following:
- E. coli
- Group B streptococci (GBS)
- Ureaplasma
- Mycoplasma hominis
The infection can start in the vagina, anus, or rectum and spread into the uterus. It can also begin in the uterus if a tear or other rupture allows bacteria to spread there.
Risk Factors for Chorioamnionitis
Not all women are at risk of chorioamnionitis. Your age, physical well-being, and lifestyle or health conditions could make you more likely to get it.
Some reasons that increase your chances of developing chorioamnionitis are as follows:
- Your water breaks prematurely.
- You have a very long labor before delivery.
- You get a lot of vaginal exams during labor.
- You have a sexually transmitted infection.
- You have a separate vaginal, urinary, or placental infection.
- You’re having your first child.
- You’re having another child, and you experienced chorioamnionitis during your first pregnancy.
- You get epidural anesthesia during labor.
- You have a short cervix.
- You use drugs, tobacco, or alcohol.
- You get internal fetal monitoring during labor.
- Your immune system is weaker than normal.
Chorioamnionitis Symptoms
Sometimes, women don’t display symptoms of chorioamnionitis, especially if they develop it earlier in their pregnancy. In most cases, the most common symptom is a persistent fever above 100.4 F.
Other signs and symptoms may include the following:
- Rapid heartbeat (above 100 beats per minute)
- Fetal rapid heartbeat (above 160 beats per minute)
- Tender uterus
- Sweating
- Bad-smelling fluid discharge
Chorioamnionitis effects on the baby
Chorioamnionitis can affect a fetus and cause infections and dangerous problems in the lungs or brain. It can also lead to severe conditions in a newborn, including pneumonia, brain damage, meningitis, sepsis, and even death. Other possible long-term complications in infants include cerebral palsy and bronchopulmonary dysplasia.
Chorioamnionitis during labor and after delivery
Chorioamnionitis can lead to a blood infection in the birth parent, known as bacteremia, which can cause premature delivery.
Other maternal complications during labor and after delivery can include:
- Need for greater help during delivery
- Postpartum uterine atony with hemorrhage (when the uterus doesn’t contract after delivery, causing too much bleeding)
- Peritonitis (inflammation of the tissue lining the abdomen)
- Adult respiratory distress syndrome (a lung condition where fluid leaks into the lungs)
- Death (rare)
Chorioamnionitis Diagnosis
Only a doctor can properly diagnose this serious condition. The most common way to diagnose chorioamnionitis is through a physical exam to check for the signs and symptoms.
Your doctor may order blood culture and urine tests as well. These tests check for the presence of bacteria in your body. A complete blood count (CBC) test checks your white blood cell count and other markers.
Along with these tests, your doctor may order a GBS vaginal culture, an ultrasound, and a sample of your amniotic fluid. Usually, the amniotic fluid sample can only be taken if your water has already broken.
Chorioamnionitis Treatment
As chorioamnionitis is a serious infection, it needs immediate treatment. Antibiotics are the most common treatment to keep the infection under control. They’re given in the vein and are known as intravenous antibiotics. You may also get acetaminophen to reduce your body temperature.
You’ll need to keep taking antibiotics until the infection has cleared. If you develop the infection during labor, you must continue to take antibiotics until after the baby is born.
If your baby has picked up the infection and their condition isn’t stable, your doctor may suggest that you induce labor. Once your baby is born, they’ll also receive direct IV antibiotics.
Chorioamnionitis Complications
There are many potential complications of chorioamnionitis for the mother and baby.
You may develop the following complications:
- Bleeding after delivery
- Blood clots in the leg
- Pelvic sores
- Endometritis (inflammation of the uterine lining, caused by infection)
- Sepsis
In serious cases, you may develop these complications:
- Septic shock
- Small clots throughout the bloodstream
- Shortness of breath with skin turning blue
Your baby may develop the following short-term or long-term complications:
- Sepsis
- Meningitis
- Pneumonia
- Seizures
- Cerebral palsy
- Abnormal brain function
- Lung disease
If the infection is widespread long before your doctor diagnoses it, your pregnancy may result in stillbirth or the baby's death after delivery.
Can You Prevent Chorioamnionitis?
Sometimes, you can prevent chorioamnionitis. But you may develop this infection regardless of preventive measures.
Routine checkups may identify vaginal inflammation or early signs of infection. During your last month of pregnancy, your doctor may also order blood tests that check for GBS — a common bacteria that causes chorioamnionitis.
During labor, your chances of developing the infection decrease when you have fewer vaginal exams and don’t use internal fetal monitoring.
If you display any of the above signs and symptoms, reach out to your doctor. Regular checkups could help you enjoy a healthy, complication-free pregnancy and delivery.
Takeaways
Chorioamnionitis is a serious infection that can happen during pregnancy. It happens when bacteria enter the amniotic fluid or tissues or membranes surrounding a fetus. It can lead to serious health complications, including sepsis in the birth parent as well as in the newborn. If you have symptoms of the condition, including fever or foul-smelling vaginal discharge, talk to your doctor immediately. They may recommend delivering your baby early or treatment with antibiotics before and after delivery.
Chorioamnionitis FAQs
Can chorioamnionitis harm the baby?
Yes, chorioamnionitis can cause harm to a fetus and a newborn. Complications can include sepsis, meningitis, pneumonia, seizures, and other serious medical conditions.
What are the odds of getting chorioamnionitis?
In the U.S., chorioamnionitis affects about 1%-5% of full-term births, but it can affect 40%-70% of preterm births. It is a common cause of premature delivery.
What are the 4 Ts of chorioamnionitis?
There isn’t a specific set of four Ts of chorioamnionitis. But the Gibb’s criteria — which is often used to diagnose chorioamnionitis— includes the following signs and symptoms:
- Maternal tachycardia
- Fetal tachycardia
- Uterine tenderness
- Fever
- Foul-smelling amniotic fluid
