Podcast Summary

The OB/GYN Resident Survival Guide

Episode #17: Diagnose & Manage Intraamniotic Infection (Intrapartum Edition)

Host: Dr. KC Miller
Date: January 26, 2026

Episode Overview

In this high-yield episode, Dr. KC Miller tackles the practical diagnosis and management of intraamniotic infection (IAI), formerly known as chorioamnionitis. With clear explanations geared toward OB/GYN residents and medical students, Dr. Miller breaks down critical steps for recognizing risk, making the diagnosis, and applying evidence-based treatment protocols on labor and delivery.

Key Discussion Points & Insights

1. Definition and Pathogenesis

• IAI involves infection of the placenta, amniotic fluid, membranes, decidua, and potentially the fetus.
• Most commonly results from ascending infection from the lower genital tract, but can also follow invasive procedures (amniocentesis, CVS, cerclage placement) or, rarely, hematogenous spread from maternal infection.
  Quote (00:22):

  “IAI is defined as an infection of the placenta, amniotic fluid, membranes, decidua and/or of the fetus.” – Dr. Miller

2. Maternal and Neonatal Risks

• Maternal: Increased risk for dysfunctional labor, postpartum hemorrhage, endometritis, sepsis (and severe sequelae like ARDS, septic shock, death).
• Neonatal: Pneumonia, meningitis, cerebral palsy, bronchopulmonary dysplasia (especially preterm), sepsis, and death.
• Emphasis on the importance of prompt recognition and management to improve outcomes.

3. Risk Factors

• Prolonged labor
• Prolonged rupture of membranes: ≥18 hours
• Nulliparity
• Use of intrauterine monitors (FSC, IUPC)
• Preexisting genital tract/STI infections
• Meconium-stained fluid
• GBS (Group B Streptococcus) colonization

Notable Insight (01:45):

• Contrary to tradition, a 2012 study showed no association between exam frequency and intrapartum fever, regardless of rupture status.
  Quote (02:03):

  “There actually was no association found between exam frequency and intrapartum fever, and that was regardless of membrane rupture status.” – Dr. Miller

4. Diagnosis of IAI

• Confirmatory diagnosis: Amniotic fluid studies or histopathological evaluation of placenta (rarely done in practice).
• Diagnosis is usually clinical:
  • Suspected IAI:
    • Isolated maternal temp ≥39°C (102.2°F)
    • Or: Temp 38–38.9°C (100.4–102.1°F) plus at least one of:
      • Maternal leukocytosis
      • Fetal tachycardia
      • Purulent cervical drainage
  • Actionable Point (04:07):

    “If the temperature is 39 degrees or greater, you should have high suspicion and treat for IAI even in the absence of those clinical findings.” – Dr. Miller

5. Management Principles

• Rapid Antibiotic Initiation: Reduces maternal and neonatal morbidity, hospital stay.

• First-Line Antibiotics:

  • IV Ampicillin + IV Gentamicin
  • Penicillin Allergy:
    • Low/moderate risk: Use Cefazolin
    • High risk (hives, angioedema, anaphylaxis): Use Clindamycin or Vancomycin

      “A high risk penicillin allergy, where you would not want to use cefazolin … would be the historic development of hives, flushing, angioedema, anaphylaxis, things like that.” (07:14)

• Add Antipyretics: e.g., Tylenol for maternal fever control

• Follow Sepsis Protocols:

  • IV fluids, bloodwork (CBC, cultures, lactate), close monitoring.
  • Match hospital’s maternal sepsis protocol; similar to standard adult sepsis protocols.
  • Quote (06:10):

    “Your hospital may have a maternal sepsis protocol that triggers whenever the patient meets criteria ... it’s very similar to the routine adult sepsis protocol.” – Dr. Miller

• NICU/Neonatology Team Notification:

  • Always alert peds/neonatal ICU team so they can assess the newborn at delivery.

6. Duration of Treatment

• During Labor: Continue antibiotics until delivery.
• After Delivery:
  • Vaginal delivery: Can discontinue antibiotics after birth.
  • Cesarean section: Give one additional post-op dose due to higher risk of endometritis.

    “The idea here is that the risk of developing endometritis at baseline is much higher after cesarean because of the instrumentation inside the uterus.” (09:11)

• Persistent Fever/Sepsis: Extend antibiotics as clinically warranted.

  “If the patient is having persistent fevers after delivery… it’s completely acceptable and often necessary to continue antibiotics for a prolonged period of time.” (10:03)

7. Source Control

• Ultimate Source Control: Delivery of baby and placenta.
• Expect possible lag in clinical improvement post-delivery.

  “In many cases it may take several hours after source control has been achieved before the patient deferves and the sepsis resolves.” (10:29)

Notable Quotes & Memorable Moments

• “Although these infections are relatively uncommon, it’s very important to know how to diagnose and manage IAI because outcomes for both the mother and the neonate can be much poorer.” (00:49)
• “If the temperature is 39 degrees or greater, you should have a high suspicion and treat for IAI even in the absence of those clinical findings.” (04:07)
• “The only way to actually confirm an intraamniotic infection is by running studies on the amniotic fluid or performing a pathologic evaluation of the placenta… but we can diagnose and treat when there is clinical suspicion.” (03:19)
• “The standard is IV ampicillin and IV gentamicin. However, if the patient has a penicillin allergy… replace the ampicillin with either cefazolin, clindamycin, or vancomycin.” (07:00)

Timestamps for Important Segments

• 00:22 – Definition and pathogenesis of IAI
• 00:49 – Maternal and neonatal complications/risks
• 01:30 – Risk factors and recent study on vaginal exam frequency
• 03:19 – Challenges with confirmatory diagnosis; clinical diagnosis criteria
• 04:07 – Diagnostic thresholds for IAI (fever + other signs)
• 05:00 – Initial management principles (antibiotics, antipyretics, sepsis protocol)
• 06:40 – Role of pediatric team at delivery
• 07:00 – Detailed antibiotic choices, penicillin allergy approach
• 08:30 – Duration of antibiotic therapy, post-delivery considerations
• 09:11 – Rationale for extra antibiotic dose post-cesarean
• 10:03 – Management of persistent fever and sepsis
• 10:29 – Source control and expected recovery timeline
• 11:10 – Episode summary and high-yield recap

Episode Recap

• IAI: Infection involving amniotic components and/or fetus, most often due to ascending infection.
• Diagnosis: Mostly clinical—maternal fever ≥39°C alone or 38–38.9°C plus leukocytosis, fetal tachycardia, or purulent cervical drainage.
• Management:
  • Swift IV antibiotics (ampicillin + gentamicin; alternatives for allergies)
  • Treat maternal fever
  • Follow institutional sepsis protocols and notify NICU/peds team
• Antibiotic Duration: Throughout labor; post-delivery approach depends on delivery route.
• Key Principle: Source control (delivery) is the goal; clinical improvement may lag.

References and further reading are available in the show notes. For additional resources, visit www.drkcmiller.com.