Definition

Chorioamnionitis, or intra-amniotic infection, is an infection of the membranes and amniotic sac during pregnancy. It is one of the most serious infections. It occurs when bacteria infect the chorion, amnion, and amniotic fluid (amniotic fluid) surrounding the fetus. This can lead to preterm labor or serious infections in the mother and baby. 

The National Institute of Child Health and Human Development (NICHD) and the American College of Obstetricians and Gynecologists (ACOG) have come up with a new term to replace chorioamnionitis. The term is intrauterine inflammation or infection or both, abbreviated as tripe I.

However, inflammation or infection that occurs in the amniotic fluid is still generally known as chorioamnionitis. 

Causes

Chorioamnionitis most commonly results from the entry of bacteria from the lower reproductive tract, specifically the cervix and vagina. However, all normal pregnant women have microorganisms living in their reproductive tracts. During pregnancy, pregnant women also form a mucus plug that covers the cervix so that bacteria and other microorganisms cannot enter the uterus.

Chorioamnionitis occurs when this protective mechanism fails to prevent infection or there are too many bacteria in the lower reproductive tract.

Other causes of bacterial entry include the spread of bacteria through the blood due to the presence of bacteria in the pregnant woman's blood (bacteremia) penetrating the placenta or through contamination of the amniotic cavity through medical procedures such as vaginal probing after rupture of membranes or amniocentesis procedures (collection of amniotic fluid for examination). However, the route of bacterial entry through these mechanisms is rare.

Risk Factor

There are several things that can increase the chances of pregnant women experiencing chorioamnionitis, including:

• Preterm labor. Many studies have reported a relationship between these two conditions, but the exact mechanism of occurrence is unknown. There are other factors besides preterm labor that are also found in chorioamnionitis cases, such as gum infections, blood types A and O, alcoholism, and obesity during pregnancy.
• Amniotic sac rupture that occurs more than 24 hours before labor.
• Prolonged labor.
• Vaginal infections, sexually transmitted infections, or urinary tract infections. Screening and treatment of bacterial vaginosis and other genital infections are known to prevent preterm labor, especially if done before the 20th week of pregnancy.
• Poor oral health. Although controversial, existing studies suggest a possible relationship between gum infections and preterm labor. Treatment of gum infections during pregnancy is also thought to reduce the rate of preterm labor.
• Group B streptococcus bacterial infection.
• Frequent vaginal examination after rupture of membranes.
• Internal fetal or uterine monitoring.

Symptoms

The symptoms of chorioamnionitis may vary. The following are the most common signs and symptoms:

• Fever during labor. This is characterized by a body temperature of at least 39°C or 38°C-38.9°C at two examinations 30 minutes apart without any other definite cause.
• Increased heart rate of the pregnant woman, which is >100 beats per minute.
• Decreased blood pressure.
• Increased fetal heart rate, which is >160 beats per minute for 10 minutes or longer.
• Vaginal discharge that smells or has a pus-like color.
• Other symptoms, such as a painful uterus and sweating.

Fever during delivery is by far the most prevalent and crucial symptom of chorioamnionitis that needs to be observed in order to make a diagnosis. It's crucial to remember, too, that fever can also happen if the mother is given anesthesia to go through delivery. Long-term labor, exhaustion, dehydration, ruptured membranes that happened far in advance of delivery, and first pregnancy are all risk factors for the woman getting a fever following anesthesia.

Diagnosis

The diagnosis is based on clinical findings and laboratory tests. The doctor may ask about risk factors associated with the onset of chorioamnionitis, such as under-term gestation and rupture of membranes. However, the diagnosis of chorioamnionitis is mainly based on clinical findings. The pregnant mother will be examined for signs and symptoms of chorioamnionitis, such as temperature screening to detect fever and blood pressure measurement. A diagnosis of chorioamnionitis can usually be made if a fever is present along with two other symptoms.

Newborn babies are at risk of sepsis, a life-threatening infection of the body. Babies with sepsis usually show nonspecific symptoms, such as:

• Behavioral disturbances, such as weakness, weak crying, and an inability to suckle
• Increased pulse rate
• Rapid breathing, blue around the mouth and fingers (cyanosis), or even no breathing
• Seizures
• Pallor, excessive bleeding or bleeding spots on the skin

In addition to clinical findings, laboratory investigations may also be performed to support the diagnosis. A high white blood cell count (leukocytosis) from a complete blood test or urine test supports the diagnosis of chorioamnionitis, if followed by the presence of signs and symptoms of chorioamnionitis in the pregnant woman.

The doctor may also order a vaginal culture or take a sample of amniotic fluid to check if there are any germs in the sample. In addition, the doctor will also perform an ultrasound examination to determine the health of the fetus.

Management

Chorioamnionitis is a disease caused by a bacterial infection, so the doctor will give you antibiotics to treat the infection. Antibiotics are generally given by intravenous injection (injection into a vein).

The doctor may encourage you to deliver your baby early. This is to reduce the chance of complications for the mother and baby. After delivery, antibiotics may be continued.

Ampicillin is one antibiotic that is beneficial for the treatment of chorioamnionitis. Learn more about Ampicillin Trihydrate here  Ampicillin Trihydrate.

Complications

If pregnant women experience severe cases of chorioamnionitis or the condition is not treated promptly, there are several complications that can arise, including:

• Infections in the hip and abdominal area
• Infection and inflammation of the uterine wall (endometritis)
• Formation of blood clots in the hip or lung area
• Sepsis, a life-threatening blood infection

Newborn babies can also experience complications from bacterial infections, including:

• Babies who develop sepsis
• Meningitis
• Impaired brain function
• Pneumonia

Prevention

In some cases, mothers will still experience chorioamnionitis despite taking precautions. Regular pregnancy checkups can identify early signs of infection. In cases where the membranes break early, antibiotics may be administered to avoid infection.

It is advised to avoid conducting vaginal examinations repeatedly once the membranes have ruptured. Pregnant women can also undergo group B streptococcus bacteria screening in the third trimester of pregnancy to detect and treat possible infections.

When to See a Doctor?

Immediately contact the nearest health facility if the mother experiences rupture of membranes. You may have chorioamnionitis if you have a fever, hip or abdominal pain, and vaginal discharge that smells or looks like pus. Report these symptoms to the doctor.

Looking for more information about other diseases? Click here!