Infant chorioamnionitis (or intra-amniotic infection) is an infection of the membranes surrounding the fetus in the uterus and the amniotic fluids. It occurs in approximately two percent of births, and when detected and treated promptly, there are usually no long-term complications for the mother or her baby.
As a result of this reassuring fact, doctors and nurses can sometimes drop their guard when facing this infection. Infant chorioamnionitis is a severe condition that demands vigilance and immediate treatment. The consequences of failure to treat this infection can cause an injury to the child’s brain and every other vital organ.
What is Chorioamnionitis in Pregnancy?
Infant chorioamnionitis is characterized by the inflammation of fetal membranes and/or amniotic fluid due to bacterial infection. The membranes that may become infected are the Amnion (or inner membrane, which touches the amniotic fluid surrounding the fetus) and the Chorion (or outer membrane, which is the closest to the mother and supports the Amnion.
If diagnosed and treated promptly (usually with antibiotics), recovery is usually quick, but if the infection develops and spreads without proper treatment, it can have numerous severe consequences.
What Causes Chorioamnionitis?
As with any infection, the proximate cause of chorioamnionitis is the growth and spread of harmful bacteria. The risk of this condition developing increases with prolonged labor, as well as a premature rupture of the amniotic sac (“water breaking”) before delivery, higher numbers of vaginal examinations in the final month of pregnancy, Group B strep, a short cervix, and/or urinary tract infections during pregnancy.
What Are the Signs and Symptoms of Chorioamnionitis?
Before delivery, chorioamnionitis is diagnosed because of maternal fever and at least two of the following additional symptoms:
- Maternal leukocytosis (high white blood cell count greater than 15,000)
- Maternal or Fetal tachycardia (heartbeat over 100 bpm)
- Uterine tenderness
- Diaphoresis (excessive sweating)
- Vaginal discharge
- The foul odor of the amniotic fluid
For infants, a diagnosis is typically made based on the following symptoms:
- Weak cries, poor sucking, and fatigue
- Pulmonary problems, such as respiratory distress, apnea, and cyanosis
- Gastrointestinal problems, which may include bloody stools, vomiting, and diarrhea
- Hematologic problems, such as pallor or purpura
How Is Chorioamnionitis Diagnosed?
Chorioamnionitis can be diagnosed through various methods, including amniotic fluid culture, Gram staining, or a combination of both, along with biochemical analysis.
However, in most cases involving postpartum individuals, the diagnosis relies primarily on clinical evaluation of symptoms and signs. Chorioamnionitis or intraamniotic infection is categorized upon diagnosis into three distinct groups:
- Isolated Maternal Fever (not Triple I): In this category, a pregnant person has a fever, but it is not necessarily indicative of a full-blown intraamniotic infection (Triple I). It means there is an isolated elevation in the mother’s body temperature, which may or may not be associated with an infection in the amniotic fluid or membranes. It’s a milder form of chorioamnionitis.
- Suspected Triple I: This category suggests a suspicion of a more severe condition known as “Triple I,” which stands for “Intraamniotic Infection and Inflammation.” It implies that some signs and symptoms strongly indicate the presence of an infection or inflammation within the amniotic sac and membranes, but it hasn’t been confirmed definitively through diagnostic tests yet. Healthcare providers are concerned about the possibility of Triple I.
- Confirmed Triple I: This is the most severe category. It means that diagnostic tests or clinical findings have confirmed the presence of an intraamniotic infection and inflammation (Triple I). In this case, there is clear evidence of an infection or inflammation within the amniotic sac, which can pose significant risks to the mother and the developing fetus. It often requires immediate medical attention and intervention.
What Kind of Complications Can Arise From Chorioamnionitis?
If a case of chorioamnionitis isn’t adequately treated or is especially severe, some of the possible complications for the mother include:
- Endometritis (infection in the uterus lining)
- Sepsis (blood infection)
- Abdominal or pelvic infection
- Blood clots in the pelvis or lungs
Complications for your child can include sepsis, respiratory problems such as pneumonia, and meningitis (infection of the spinal cord and brain). Chorioamnionitis is also a risk factor for developing brain complications such as cerebral palsy, periventricular leukomalacia, and premature birth.
Other complications that can develop include villitis, hypoxic-ischemic encephalopathy (HIE), funisitis, hydrops fetalis, and intrauterine growth restriction (IUGR).
Although some of these conditions – such as funisitis and villitis – are usually benign, they can increase the risk of stillbirth and fetal death. Due to the risk or presence of these complications, chorioamnionitis may also warrant neonatal intensive care admission.
It is important to note all of these infections are more likely to develop and become fatal for premature babies. However, the risks are still relatively rare in these cases, with around a 15% chance of brain complications and a 10-20% chance of developing pneumonia.
- Learn about chorioamnionitis birth injury lawsuits.
Can Chorioamnionitis Cause Stillbirth?
Unfortunately, chorioamnionitis can result in stillbirth in the most severe cases. Although this will only rarely happen if promptly diagnosed and treated, in some cases, such as when chorioamnionitis occurs earlier in pregnancy and is asymptomatic, stillbirth can be more likely.
In addition, the risk of stillbirth may be increased by the development of complications such as funisitis, infection, and umbilical cord inflammation.
Although chorioamnionitis does not usually result in stillbirth, it is one of the most common causes, with one study finding that 37% of stillbirths were linked to the condition.
What Is the Treatment for Chorioamnionitis?
Treatment for chorioamnionitis typically involves the prompt administration of intravenous antibiotics, which have a high rate of aiding successful recovery in cases such as a group B strep infection.
In other cases, treatment may require immediate delivery of the baby. Either way, antibiotics are commonly prescribed for both the mother and her child after delivery, usually for a day or two.
Supportive measures such as the use of acetaminophen (Tylenol) can also be significant during delivery to help prevent the occurrence of brain damage (but you also have to consider the possible acetaminophen/autism or ADHD concern).
In addition to antibiotics, some additional forms of treatment may include:
- Infant intubation and ventilation
- Balancing glucose levels
- Artificial breathing tubes for the infant
In severe cases, surgery may also be necessary for your child if any of these symptoms are present:
- Subcutaneous (beneath the skin) or brain abscess
- Infections around the pleural area (of the lungs)
- Severe abdominal infections
- Bone and/or joint infections
Is there an increased risk that the child will be born with cerebral palsy if the mother has chorioamnionitis?
If a mother has chorioamnionitis as an infection in the placenta, there is as much as ten times greater risk that the child will be born with some cerebral palsy.
What is the Difference Between Histological Chorioamnionitis and Clinical Chorioamnionitis?
If chorioamnionitis is diagnosed based on the mother or child’s symptoms, it is clinical chorioamnionitis. Histological chorioamnionitis is diagnosed by looking at the placenta. So if the mother has no symptoms, but the doctors later put the placenta and look under the microscope, they find chorioamnionitis, that’s histological chorioamnionitis.
What are the ACOG Recommendations for Treating Chorioamnionitis?
The American College of Obstetricians and Gynecologists (ACOG) is an educational resource to aid clinicians and has made its recommendations. (It also acts as an arm for doctors to avoid malpractice lawsuits, but that is a different story.)
For the treatment of chorioamnionitis, the ACOG’s recommendations are that:
- Administration of intrapartum antibiotics is recommended whenever an intraamniotic infection is suspected or confirmed. Antibiotics should be considered in the setting of isolated maternal fever unless a source other than intraamniotic infection is identified and documented.
- Regardless of institutional protocol, when obstetrician-gynecologists or other obstetric care providers diagnose an intraamniotic infection or when other risk factors for early-onset neonatal sepsis are present in labor (e.g., maternal fever, prolonged rupture of the membranes, or preterm birth), communication with the neonatal care team is essential to optimize neonatal evaluation and management.
That ACOG Guideline relates to expectant management following premature rupture of membranes. It does not explicitly address either (1) the criteria for a clinical diagnosis of chorioamnionitis or (2) the intrapartum management of a patient who meets the clinical diagnosis of chorioamnionitis.