Chorioamnionitis Differential Diagnoses

Updated: May 08, 2018
  • Author: Fayez M Bany-Mohammed, MD; Chief Editor: Ted Rosenkrantz, MD  more...
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DDx

Diagnostic Considerations

As noted earlier, the diagnosis of clinical maternal chorioamnionitis made on the basis of clinical findings of fever plus fetal tachycardia, maternal leukocytosis, or purulent fluid coming from the cervical os (see the table below). Affected women with chorioamnionitis may appear ill, even toxic, and they may exhibit hypotension, diaphoresis, and/or cool or clammy skin. However, maternal clinical signs or symptoms of infection may be absent, particularly when dealing with histologic chorioamnionitis (silent chorioamnionitis). [5]

Table. Features of Isolated Maternal Fever and Triple I with Classification. [141] (Open Table in a new window)

Terminology Features and Comments
Isolated Maternal Fever 

 

(“Documented” fever)

Maternal oral temperature ≥39.0°C (≥102.2°F) on any one occasion is documented fever. If the oral temperature is between 38.0°C (100.4°F) and 39.0°C (102.2°F), repeat the measurement in 30 minutes; if the repeat value remains at least 38.0°C (≥100.4°F), it is documented fever.

Suspected Triple I

Fever without a clear source plus any of the following:

  • Baseline fetal tachycardia (>160 beats per min for 10 min or longer, excluding accelerations, decelerations, and periods of marked variability)
  • Maternal white blood cell count >15,000 per mm 3 in the absence of corticosteroids
  • Definite purulent fluid from the cervical os

Confirmed Triple I

All of the above plus:

  • Amniocentesis-proven infection through a positive Gram stain
  • Low glucose level or positive amniotic fluid culture
  • Placental pathology revealing diagnostic features of infection

Important considerations

In the United States, civil litigation is an increasing threat to healthcare professionals. [142] This is particularly true for obstetricians and neonatologists. These caregivers have ways to avoid the experience through high-quality care and complete documentation of the clinical course. [142, 143, 144]

The initial signs and symptoms of neonatal infections may be subtle or absent; they may be followed by a rapid and devastating course. The potential for severe disability or death as a consequence of neonatal bacterial infection has resulted in the treatment of 1 infected infant of every 20 infants (or even up to 80-210 [73, 74, 75] ) who received initial therapy but had no proven disease. The evaluation to exclude sepsis is a classic example of the difficulty in differentiating infants with infection from those who are not infected. Antibiotic therapy for early-onset neonatal sepsis is a representative example of family practitioners and pediatricians practicing defensive medicine. If the diagnosis and treatment of obvious meningitis and sepsis are missed in the neonate, physicians, other healthcare professionals, and the hospital face significant medicolegal risk. [145]

The importance of chorioamnionitis takes on added medicolegal significance, because several carefully controlled studies demonstrate an association between intrauterine infection and cerebral palsy in term infants, [146, 147] as well as in preterm infants. [148, 149]  Thus, the legal profession has seen an opportunity for litigation, and attorneys have filed lawsuits that suggest earlier antibiotic therapy could have mitigated cerebral palsy. This is not the situation.

Readers are referred to a 2007 article in Clinics in Perinatology that discussed how caregivers can facilitate better understanding of an infant's hospitalization by the parents. [150]  Accurate, complete, and compassionate communication with parents about the critical condition of their preterm infant, or any infant in a neonatal intensive care unit (NICU), can help to avoid litigation. Medical record documentation of both the infant's overall disease state and (a) conversation(s) with the parents about their infant's condition are two essential elements in preventing litigation.

Special concerns

Epidural anesthesia

The adverse effects of epidural anesthesia on the mother and her newborn continue to be unresolved issues. Labor may be prolonged by epidural anesthesia [151] ; thus, mothers who receive this type of anesthesia may become dehydrated and exhausted, and they may also develop an elevated temperature. [152]  In turn, their fetus may have an increased heart rate associated with epidural anesthesia and maternal fever. The presence of maternal fever and fetal tachycardia initiate an investigation of the cause, and the obstetrician often administers antibiotics. Intermittent labor analgesia reduces the incidence of maternal fever more than continuous epidural analgesia. [153] Epidural-related fever is rarely attributable to intraamniotic infection, but it is often associated with sterile inflammation and elevation in interleukin (IL)-6)levels in maternal blood (see the discussion under Physical Examination). [154]

The neonate may be born in a febrile state. [155] Typically, newborns appear and act healthy after intrapartum epidural anesthesia. Elevated temperature in neonates rapidly returns to normal in babies without infection. Controversy surrounds conducting an evaluation for sepsis in neonates with this history. A minority of pediatricians or family practitioners may elect to perform an evaluation for sepsis and treat for 48 hours with antibiotics pending the culture results.

Despite the observation that most febrile infants are well after a mother has epidural anesthesia during labor, an assessment nevertheless should be cautious.

Urogenital infections

A major and unresolved problem during pregnancy is urogenital infections caused by U urealyticum and Mycoplasma hominis. The high percentage of cord blood-related cultures positive for these pathogens is a relatively recent and disturbing trend; positive cultures were strongly associated with placental inflammation and preterm birth. [156]

The lungs of very preterm infants are also inflamed from intrauterine infection with U urealyticum and M hominis. These infections are apparently related to the pathogenesis of bronchopulmonary dysplasia (see the discussion under "Neonatal sequelae" under Prognosis). [157]

Other problems to be considered

Other conditions that should be considered in patients with suspected chorioamnionitis include the following:

  • Sexually transmitted diseases that cause pelvic infection and inflammation

  • Viral infections (eg, urogenital disease caused by herpes simplex virus)

  • Pelvic adenitis (eg, herpes simplex, enteroviral infections [ie, Coxsackie virus])

Differential Diagnoses