Chorioamnionitis: Diagnosis and Management
Immediate Action Required
Start broad-spectrum intravenous antibiotics (ampicillin 2g IV loading dose, then 1g IV every 4 hours plus gentamicin weight-based dosing) immediately upon clinical diagnosis and proceed to delivery without delay—chorioamnionitis cannot be cured by antibiotics alone and maternal sepsis can progress to death within a median of 18 hours from first signs. 1
Clinical Diagnosis
Do not wait for maternal fever to make the diagnosis. 1 Chorioamnionitis presents with maternal fever (≥100.4°F/38.0°C) plus at least one of the following: 1, 2
- Maternal tachycardia
- Fetal tachycardia
- Uterine tenderness
- Purulent or foul-smelling amniotic fluid
- Maternal leukocytosis (>15,000 cells/mm³)
The condition can present without fever, especially at earlier gestational ages—treatment should begin as soon as any other sign of infection appears. 1 Amniocentesis results must not delay therapy; proceed based on bedside clinical assessment. 1
Maternal Antibiotic Regimen
First-line treatment: Ampicillin 2g IV initial dose, then 1g IV every 4 hours until delivery PLUS gentamicin (loading dose followed by weight-based maintenance dosing). 1, 2 This regimen covers the polymicrobial nature of intraamniotic infection. 1
For non-severe penicillin allergies: Cefazolin 2g IV initial dose, then 1g IV every 8 hours until delivery (replacing ampicillin). 1, 2
For severe penicillin allergies: Clindamycin 900mg IV every 8 hours OR vancomycin 1g IV every 12 hours until delivery. 1, 2
If cesarean delivery is performed: Add clindamycin at the time of umbilical cord clamping. 3
Timing of Antibiotics
Initiate antibiotics within 3 hours of fever recognition, or within 1 hour if septic shock is suspected. 1 Blood cultures should be obtained before antibiotic administration when feasible, but do not delay treatment. 1
Delivery Considerations
Delivery should be undertaken without delay once antibiotics are started. 1 The infection cannot be cured by antibiotics alone and requires delivery regardless of gestational age. 1, 3, 4
Route of delivery is dictated by standard obstetric indications—not by the infection itself. 1, 4 Cesarean delivery offers no fetal advantage and may increase maternal morbidity. 1 Vaginal delivery is the safer option. 3
Common pitfall: The time interval between diagnosis and delivery is not related to most adverse outcomes, but delivery should not be unnecessarily delayed. 3 Patients may require higher doses of oxytocin to achieve adequate uterine activity. 3
Postpartum Antibiotic Management
After vaginal delivery: Additional antibiotic therapy does not appear necessary. 3
After cesarean delivery: If postdelivery antibiotics are prescribed, there is support for administering one additional dose. 3
Neonatal Management
Well-Appearing Newborns
Obtain limited evaluation: Blood culture and CBC with differential. 1, 2
Start empirical antibiotics immediately: IV ampicillin (for GBS coverage) plus an aminoglycoside (gentamicin) or cefotaxime (for E. coli coverage). 1, 5
CBC timing: Sensitivity improves when sampled 6–12 hours after birth, but antibiotic therapy must not be delayed awaiting results. 1
Discontinue antibiotics once clinical course and laboratory data exclude sepsis. 1
Newborns with Any Sign of Sepsis
Perform full diagnostic work-up: 1, 5
- Blood culture
- CBC with differential
- Chest radiograph if respiratory symptoms present
- Lumbar puncture if infant is stable (critical because blood cultures can be sterile in 15-33% of newborns with meningitis) 5
Start empirical broad-spectrum antibiotics immediately with the same regimen as above (IV ampicillin plus gentamicin or cefotaxime). 1, 5
Key neonatal warning: Approximately 90% of early-onset GBS disease manifests within the first 24 hours of life. 5 Intrapartum antibiotics do not mask or delay clinical presentation—signs of sepsis will still appear rapidly. 5
Critical Prognostic Data
In women with preterm premature rupture of membranes (PPROM) managed expectantly, intraamniotic infection occurs in 58.1% of cases, reinforcing the need for high clinical suspicion. 1
Common Pitfalls to Avoid
Never withhold antibiotics pending amniocentesis results or waiting for maternal fever to develop in suspected chorioamnionitis. 1
Do not be falsely reassured by negative maternal GBS screening—more than 60% of early-onset GBS cases occur in infants born to women with negative prenatal cultures. 5
Recognize that epidural analgesia can cause fever, potentially leading to overdiagnosis, but when clinical suspicion exists, err on the side of treatment. 2
Maternal sepsis progresses rapidly—the median interval from first infection signs to death is only 18 hours. 1 This underscores the absolute necessity of immediate antibiotic administration and delivery planning.