Chorionitis refers to an inflammation of the membranes surrounding a fetus during pregnancy. This condition is a significant complication, posing potential concerns for both the pregnant individual and the developing baby.
What is Chorionitis?
Chorionitis, also known as chorioamnionitis, is an infection or inflammation affecting the chorion and amnion, which are the two membranes that enclose the fetus. It also commonly involves the amniotic fluid, the liquid that surrounds and protects the baby in the womb. This condition typically originates from bacteria ascending from the lower genital tract into the uterus.
The infection often starts in the vagina or cervix and then travels upwards, breaching the protective barriers. Once these bacteria reach the amniotic sac, they can multiply and trigger an inflammatory response, directly impacting the fetal environment.
Causes and Risk Factors
The primary cause of chorionitis is a bacterial infection that moves upwards from the lower genital tract. Common bacteria involved in these infections include Group B Streptococcus, Escherichia coli, and various anaerobic bacteria. These microorganisms can naturally reside in the vagina or rectum, but they become problematic when they ascend into the sterile environment of the uterus.
Several factors can increase the likelihood of developing this infection. Prolonged labor, especially when the membranes have ruptured, provides a longer window for bacteria to ascend. Premature rupture of membranes, occurring before the onset of labor, removes a physical barrier against infection. Multiple vaginal examinations during labor can also introduce bacteria higher into the reproductive tract.
Existing infections in the lower genital tract, such as bacterial vaginosis or sexually transmitted infections, are significant risk factors. These conditions can alter the vaginal flora, making it easier for pathogenic bacteria to proliferate and ascend. Nulliparity, meaning a first-time pregnancy, has also been identified as a factor that may modestly increase susceptibility.
Recognizing the Signs
Recognizing chorionitis often involves observing a combination of clinical signs. A primary indicator is a maternal fever, typically above 100.4°F (38°C). The pregnant individual may also experience tenderness in the uterus.
Both the mother and the fetus might exhibit tachycardia, an abnormally rapid heart rate. The amniotic fluid, if observed after rupture of membranes, may have a foul or strong odor. Sometimes, symptoms can be subtle or even absent, making diagnosis challenging without clinical suspicion.
Diagnosis and Treatment
Diagnosing chorionitis typically relies on clinical observations and laboratory tests. A healthcare provider will assess for maternal fever, uterine tenderness, and fetal tachycardia. Blood tests are often conducted to check for signs of infection, such as an elevated white blood cell count.
An amniocentesis may be performed to collect a sample of amniotic fluid for analysis. This fluid can be tested for bacteria and inflammatory markers, providing definitive confirmation. Once chorionitis is identified, immediate treatment with broad-spectrum intravenous antibiotics is initiated.
Commonly prescribed antibiotics include ampicillin and gentamicin, which target a wide range of bacteria. The management approach typically involves expediting delivery, regardless of gestational age, to prevent further complications for both the mother and the baby. This might involve inducing labor or a Cesarean section.
Potential Outcomes and Prevention
Chorionitis can lead to several complications for both the pregnant individual and the newborn. For the mother, risks include postpartum hemorrhage (excessive bleeding after birth), endometritis (infection of the uterine lining), and sepsis.
For the baby, potential outcomes include premature birth, neonatal sepsis, and respiratory distress syndrome. Cerebral palsy can also occur.
Preventive strategies focus on managing known risk factors. Limiting vaginal examinations, especially with prolonged rupture of membranes, can help reduce bacterial introduction. Treating pre-existing lower genital tract infections, such as bacterial vaginosis, before or during pregnancy, is also important. Timely medical intervention for suspected cases, including prompt diagnosis and antibiotic administration, can minimize outcome severity.