Management of Intraamniotic Infection (Chorioamnionitis)
Initiate broad-spectrum intravenous antibiotics immediately upon clinical diagnosis—ampicillin 2g IV loading dose followed by 1g IV every 4 hours plus gentamicin (weight-based dosing) until delivery—and proceed with delivery without delay. 1
Clinical Diagnosis
Diagnose chorioamnionitis clinically based on maternal fever ≥100.4°F (38.0°C) plus at least one of the following: 1
- Maternal tachycardia
- Fetal tachycardia
- Uterine tenderness
- Foul-smelling or purulent amniotic fluid
- Maternal leukocytosis
Critical caveat: Do not delay diagnosis or treatment waiting for maternal fever to develop—intraamniotic infection can present without fever, particularly at earlier gestational ages. 2, 1 Other signs of infection (maternal tachycardia, purulent cervical discharge, uterine tenderness) mandate immediate treatment. 3
Antibiotic Therapy
First-Line Regimen
Ampicillin 2g IV initial dose, then 1g IV every 4 hours until delivery plus gentamicin (loading dose followed by weight-based maintenance dosing) until delivery. 1 This combination provides broad-spectrum coverage against the polymicrobial nature of intraamniotic infection. 4
Initiate antibiotics within 3 hours of fever recognition, or within 1 hour if septic shock is suspected. 1 Obtain blood cultures before antibiotic administration when feasible, but do not delay treatment. 1
Penicillin Allergy Alternatives
- Non-severe penicillin allergy: Cefazolin 2g IV initial dose, then 1g IV every 8 hours until delivery (plus gentamicin). 1
- Severe penicillin allergy (anaphylaxis risk): Clindamycin 900mg IV every 8 hours or vancomycin 1g IV every 12 hours until delivery (plus gentamicin). 1
Delivery Management
Proceed with delivery once antibiotics are initiated. 5, 6 Chorioamnionitis cannot be cured by antibiotics alone without delivery. 4 The route of delivery should be based on standard obstetric indications—intraamniotic infection alone is not an indication for cesarean delivery. 6, 7
Cesarean delivery offers no specific advantage to the fetus and may increase maternal morbidity risk. 5 However, if cesarean is performed for other indications, proceed without hesitation. 6
Neonatal Management Coordination
Notify neonatal care providers immediately to facilitate appropriate evaluation and treatment. 6, 7
Well-Appearing Newborns Born to Mothers with Chorioamnionitis
Perform limited evaluation (blood culture and CBC with differential) and initiate empirical antibiotic therapy pending culture results. 2, 1 This includes IV ampicillin (for GBS coverage) plus an agent active against E. coli. 1
Newborns with Signs of Sepsis
Perform full diagnostic evaluation including blood culture, CBC with differential, chest radiograph if respiratory symptoms present, and lumbar puncture if infant is stable. 1 Initiate empirical broad-spectrum antibiotics immediately. 2, 1
The sensitivity of CBC is improved if delayed 6-12 hours after birth, but do not delay antibiotic initiation. 2 Discontinue empirical therapy once clinical course and laboratory evaluation exclude sepsis. 2
Critical Pitfalls to Avoid
Never delay treatment pending amniocentesis results. 1 While amniocentesis may help diagnose intraamniotic infection, clinical management should not be delayed. 2
Never wait for maternal fever if other signs of infection are present. 2, 1, 3 Maternal sepsis can progress to death within 18 hours of symptom onset. 2, 3 The median time from first signs of infection to death in cases of maternal mortality was only 18 hours. 2
Recognize that clinical symptoms may be subtle at earlier gestational ages. 2, 8 Maintain high clinical suspicion in the setting of preterm prelabor rupture of membranes, where intraamniotic infection rates are substantially elevated (58.1% with expectant management). 2
Adjunctive Measures
Maintain maternal normothermia, as hyperthermia adversely impacts uterine contractility and may lower the threshold for fetal hypoxic brain injury. 1 Use acetaminophen and cooling measures as needed.
Monitor for postpartum hemorrhage, as chorioamnionitis increases risk of uterine atony. 6, 7 Have uterotonics readily available. 3