Podcast Summary: Dr. Chapa’s OBGYN Clinical Pearls

Episode Title: PFM Question: IAI WITHOUT Fever?

Date: December 24, 2025
Host: Dr. Chapa
Episode Purpose:
This episode addresses a nuanced and clinically significant question about diagnosing intra-amniotic infection (IAI, often referred to as chorioamnionitis) when maternal fever—the hallmark of current diagnostic criteria—is absent, but other signs such as maternal or fetal tachycardia are present. Dr. Chapa breaks down the evidence, gaps in ACOG guidelines, and practical bedside approaches for medical students, residents, and clinicians.

Main Theme and Purpose

• Exploring the Clinical Gap:
  Can you diagnose intra-amniotic infection in laboring patients without maternal fever, particularly when only maternal or fetal tachycardia is present?
• Addressing Audience Query:
  Building on the last episode (“the chorio paradox”), Dr. Chapa answers a listener’s question about a real-world scenario where the mother had tachycardia, the fetus had tachycardia, but no maternal fever.

Key Discussion Points

1. The Chorio Paradox and Diagnostic Discordance

• Histology vs. Clinical Diagnosis:
  Sometimes, clinical signs of IAI (e.g., fever, tachycardia) don’t match placental pathology, and vice versa ([00:00], [02:11]).
• Guideline Limitations:
  ACOG’s committee opinion (No. 712) bases diagnosis heavily on maternal fever—possibly overlooking non-febrile cases.

2. Listener Scenario and Key Clinical Question

• Listener's Case:

  “The mom was tachycardic and the fetus was tachycardic, but the mom never had a fever... My attending said it was chorio and we needed to treat. Could you expand on this reasoning? I thought you needed a maternal fever for the diagnosis.” — Podcast Listener ([02:11])

• Why the Question Matters:
  Highlights a real gap between guidelines and nuanced clinical care.

3. Current ACOG Diagnostic Criteria for IAI

• Three Clinical Types: ([05:14])
  • Isolated maternal fever
  • Suspected IAI (fever plus one additional sign: fetal tachycardia, uterine tenderness, or purulent fluid)
  • Pathologic chorioamnionitis (diagnosed on placental histology, often retrospectively)
• All Rest on Fever:
  Both isolated maternal fever and suspected IAI require maternal fever to initiate diagnosis.

4. Can IAI Present Without Fever?

• Short Answer: Yes.

  “Can you make the diagnosis of IAI since the current guidance from the college... pivots on... maternal fever? ...But what if there’s fetal tachycardia alone?... The short answer is absolutely.” — Dr. Chapa ([05:14])

• Supporting Evidence:
  Retrospective review of 57 cases of histologically confirmed chorioamnionitis and/or funisitis:

  “None of these mothers had elevated temperatures at the point when fetal tachycardia was first documented.” ([09:45])
  Demonstrates fetal tachycardia can precede maternal fever—in some cases, maternal fever never develops if antibiotics are initiated early.

• Fetal Inflammatory Response Syndrome (FIRS):

  “The baby is very sensitive to bacterial or microbe invasion. So the first thing that can happen... is that the baby triggers a fetal inflammatory response syndrome, FIRS.” ([11:30])

  • Pathophysiology:
    • Fetal exposure to infection/inflammation → FIRS → elevated fetal heart rate (tachycardia) due to catecholamine surge
    • Maternal pyrexia may follow or be absent if antibiotic therapy is started promptly

• Clinical Experience Corroborates:

  “We’ve done this ourselves on the ward... baby’s now tacky... she had prolonged rupture... amp and gent, baby... And as we were loading the antibiotics, of course, she spiked her temperature.” ([14:35])

5. Clinical Implications and Guidance Gaps

• Tachycardia as an Early Sign:

  • Fetal (and/or maternal) tachycardia may be the first and occasionally only clinical sign of IAI.
  • Not all fever is infection: Epidural, dehydration, or stress can also cause fever, confounding diagnosis.
  • Diagnosis should be context-specific and flexible.

• Guideline Acknowledgement:

  “There really should be a caveat in there which says sometimes guys, sometimes using the baby as a vital sign... that is the first indication of later development of intra-amniotic infection.” ([08:10])

• Practical Takeaway:

  “If you have fetal tachycardia (with or without maternal tachycardia), in the right clinical setting—even if the mom is afebrile—yes, you should suspect and treat for IAI.” ([16:15])

6. Practical Bedside Application

• Management Suggestions:

  • Start antibiotics if fetal or maternal tachycardia develops in the context of other risk factors (prolonged rupture, clinical suspicion), even in the absence of fever.
  • Inform pediatrics/neonatology accordingly.
  • Send placenta and umbilical cord gas for further analysis.

• Limits of Current Tools:
  “Our clinical diagnosis of chorio is not very sensitive and it’s not very specific, but it’s the best that we have outside of tapping the amniotic fluid and sending for interleukins… But no one’s going to want to get a tap like in between contractions.” ([17:00])

Notable Quotes & Memorable Moments

• On Guidelines vs. Clinical Reality:

  “Code is more what you call guidelines than actual rules.” — Dr. Chapa ([01:35])

• On Using Fetal Heart Rate as a Vital:

  “Sometimes using the baby as a vital sign because the fetus is its own set of vitals... that is the first indication of later development of intra amniotic infection.” ([08:10])

• On Clinical Judgement Over Guidelines:

  “The attending—absolutely correct, totally evidence-based... it is absolutely possible that fetal tachycardia be the first presenting sign of suspected IAI before manifesting maternal pyrexia.” ([10:02])

• On Diagnostic Sensitivity:

  “It just goes to show that our clinical diagnosis of chorio is not very sensitive and it’s not very specific, but it’s the best that we have…” ([16:45])

• On the Realities of Bedside Practice:

  “Could you imagine? Ma’am, I know you’re 6cm, but I need to stick this needle under ultrasound guidance to get some fluid out. Yeah, we’re not doing that.” ([17:00])

Timestamps of Key Segments

• 00:00–02:11 — Introduction, previous episode recap, setup of podcast question
• 02:11–02:39 — Listener’s scenario and core question
• 05:14–10:00 — Breakdown of diagnostic criteria, clinical gap, and guideline limitations
• 10:00–12:00 — Evidence for fetal tachycardia preceding fever, FIRS explanation
• 14:35–16:15 — Clinical experience, real ward examples, practical recommendations
• 16:45–17:30 — Diagnostic limitations, practical realities, and summary

Final Summary & Take-Home Point

• IAI can and does occur in the absence of maternal fever—sometimes, the only initial clue is fetal (or maternal) tachycardia.
• Current ACOG guidelines require fever but may miss these early/silent cases; clinical context and judgment are essential.
• Start empiric treatment when appropriate and communicate with the neonatal team.
• Clinical diagnosis is imperfect but remains the standard until faster, more sensitive bedside tests are available.

Dr. Chapa closes with thanks to the audience and well-wishes for the holidays, underscoring the importance of community and continued questioning in clinical practice.