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ob.chorioamnionitis.v1

Chorioamnionitis / Intra-amniotic Infection (IAI) / Triple I

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NEW Phase C dossier — authored 2026-05-15 for shard-5-obped-id. Covers chorioamnionitis / Intra-amniotic infection (IAI) / "Triple I" (Intrauterine Infection / Inflammation) per ACOG CO 712 (2017, reaffirmed 2022) renaming + Higgins NICHD/ACOG/SMFM 2016 workshop diagnostic categories (PMID 26855098). Affects 2-5% of term + 25% of preterm deliveries; ascending cervicovaginal flora pathway. Seed manifest authored at prisma/seed/manifests/ob.chorioamnionitis.v1.ts (defineBatch23ScaffoldManifest, specialtyPack obstetrics_gynecology, sourceWorkupIds ["chorioamnionitis"], evidenceIds ["ev_chorioamnionitis_guideline_review_required"]) with terminology anchors (icd10 / snomed / loinc) projected 1:1 verbatim from the dossier terminology block — no new codes invented. Cross-engine manifest reuse (e.g., pointing to id.sepsis.core.v1 manifest) was considered earlier but rejected as semantically misleading; a dedicated chorio scaffold manifest is the authored solution. _registry.ts NOT modified per refined shard-5 pattern (3-file set only: dossier TS + brief + research bundle). Registry edit deferred to a future shard. Distinct from id.sepsis.core.v1 (sibling — chorio escalates to sepsis pathway with OB carryover when SIRS / qSOFA fires), id.neonatal-sepsis.early-late.v1 (sibling — chorio is top maternal risk factor for EOS; mother-infant dyad parallel engines), ob.postpartum-hemorrhage.core.v1 (sibling — chorio is known atony risk factor; sequential/concurrent presentation), ob.pre-eclampsia.core.v1 (sibling — pulmonary edema risk overlap; methylergonovine CI in PE). Sibling differentiation explicitly encoded for all four. Phenotype matrix (7-axis GA × severity × prior ROM × prior cervical exams × GBS-status × pen-allergy × cesarean-vs-vaginal cross-product — 1,080 cells collapsed to 10 anchor combinations) encoded indirectly via regimen_axes.chorioamnionitis_empiric_antibiotics.steps (intrapartum_standard / cesarean_anaerobic_addon / pen_anaphylaxis / pen_mild / postpartum_continuation / sepsis_escalation) + severity_triggers (10 phenotype-specific triggers) + setting playbooks (ed / inpatient / icu / outpatient). First-class TS phenotype field is schema-blocked. Severity triggers (10): chorioamnionitis_with_maternal_sepsis_features (life_threatening — routes to id.sepsis.core.v1 with OB carryover; broaden empirics + emergent delivery), delayed_delivery_with_chorio_after_antibiotics (severe — > 6 h post-antibiotic without delivery progress → consider cesarean; Tita Andrews 2010), gbs_positive_no_intrapartum_prophylaxis_with_chorio (severe — neonatal high-risk handoff; routes to id.neonatal-sepsis.early-late.v1), postpartum_endometritis_emerging (severe — fever > 24-48 h postpartum → broaden anaerobic + ddx retained products + abscess + cesarean infection), preterm_chorio_with_neonatal_workup_required (severe — preterm + chorio → NICU + broaden neonatal empirics; routes to id.neonatal-sepsis.early-late.v1), severe_chorio_in_pregnancy_requires_icu (life_threatening — pulmonary edema / shock / multi-organ → ICU + emergent delivery + broad-spectrum), recurrent_chorio_subsequent_pregnancy (moderate — recurrence ~ 5-15%; no aspirin indication; surveillance), cesarean_delivery_post_chorio_extended_abx (severe — 48 h IV + anaerobic add-on; ACOG CO 712), pen_allergy_with_chorio_intrapartum (moderate — severity-stratified substitute regimens; ACOG CO 712), intra_amniotic_inflammation_without_infection_diagnosis (mild — Higgins 2016 sterile inflammation category; conservative surveillance). Bayesian linkage (per §5.5.2): pre-test priors documented in _research-bundles/ob.chorioamnionitis.v1.md — chorio in term deliveries ~ 2-5%; preterm deliveries ~ 25%; recurrence ~ 5-15% in subsequent pregnancy; postpartum endometritis after chorio + cesarean ~ 10-15%; maternal bacteremia in chorio ~ 5-10%; neonatal EOS after maternal chorio ~ 3-8% (Kaiser EOS-calculator stratified). Key LRs: maternal intrapartum fever ≥ 39.0 °C single OR 38.0-38.9 °C × 2 LR+ very high for Triple I; FHR > 160 sustained × 10 min LR+ ~ 3; WBC > 15K without steroids LR+ ~ 2; purulent cervical discharge LR+ ~ 5; amniotic fluid glucose < 14 mg/dL LR+ > 10; IL-6 elevated LR+ ~ 3-5 (sterile inflammation differential); ROM > 18 h LR+ ~ 2-3 antecedent risk; > 5 cervical exams LR+ ~ 2 antecedent risk. Conditional dependencies modeled: GA × incidence coupling, ROM × time-since-rupture coupling, cervical-exam × ascending-infection dose-response, GBS-IAP-adequacy × neonatal-EOS coupling, cesarean × endometritis coupling. Decision thresholds: T_treat (empiric antibiotics) = Higgins 2016 suspected Triple I (fever + ≥ 1 secondary); T_test (rule-out / isolated fever) = single fever without secondary criteria (observe + investigate); T_emergent-delivery = maternal sepsis + chorio OR Category III FHR + chorio. Cross-dossier routing: id.sepsis.core.v1 (sepsis escalation with OB carryover), id.neonatal-sepsis.early-late.v1 (newborn pathway with chorio carryover), ob.postpartum-hemorrhage.core.v1 (atony / PPH risk carryover), ob.pre-eclampsia.core.v1 (PE overlay), id.bacterial-meningitis.peds.v1 (neonatal meningitis if confirmed). ROS/DDx LR seed data NOT touched (cross-cutting; not in shard scope). Settings (4): ED (rare — usually inpatient L&D recognition; community-recognised cases trigger ED → L&D transfer with continuous fetal monitoring), Inpatient L&D (primary venue; definitive intrapartum management + expedited delivery + postpartum recovery), ICU (rare — for severe sepsis / shock / multi-organ / pulmonary edema; routes to id.sepsis.core.v1 with OB carryover), Outpatient postpartum (6-wk visit + recurrence-risk counseling + mental health + immunization + newborn high-risk peds follow-up coordination). Drug guidance grounded in ACOG CO 712 2017 + Higgins NICHD/ACOG/SMFM 2016 + ACOG CO 797 2020 + ACOG PB 188 2018 + WHO 2015 + AAP Puopolo 2018 (newborn handoff). RxCUIs referenced (RxNav live-verified 2026-05-25): ampicillin (733), gentamicin (1596450), clindamycin (2582), metronidazole (6922), vancomycin (11124), cefazolin (2180), piperacillin-tazobactam (74169), norepinephrine (7512), vasopressin (11149), hydrocortisone (5492), acetaminophen (161), iron / ferrous sulfate (24947). Influenza vaccine + Tdap rxcui set to undefined — vaccine product CUIs live under CVX, not a single RxNorm ingredient CUI (matches prev.adult-immunization.core.v1 precedent); prior fabricated codes (gentamicin 4921, cefazolin 2191→ceftazidime, norepinephrine 7980→penicillin G, ferrous sulfate 4053→erythromycin, influenza 1656584 invalid, Tdap 1144329 NotCurrent) corrected this pass. Open gaps: (1) Phenotype matrix not first-class TS field — schema-blocked. (2) Bayesian LR seed data not encoded — lives in narrative + research bundle only this pass; ROS/DDx seed edit cross-cutting. (3) Seed manifest is a batch-23 routing scaffold — disease-specific regimen/safety atoms remain gated for guideline + terminology review before any ACTIVE-tier promotion. (4) Manifest now authored at prisma/seed/manifests/ob.chorioamnionitis.v1.ts (terminology projected 1:1 from dossier); the separate .atoms.ts companion file was not authored (scaffold manifest does not require it). (5) Co-located test file (ob.chorioamnionitis.test.ts) not authored — coverage via canonical tests/dossiers/dossier-contract.test.ts only. (6) _registry.ts NOT modified per refined shard-5 pattern — registry edit deferred to a future shard. (7) ACOG CO 712 (2017) does not carry a stable PubMed PMID — cited by year + bulletin number; closest indexed PMID is Higgins NICHD/ACOG/SMFM 2016 (26855098). (8) Vaginal microbiome / probiotic research is emerging — no formal intervention recommended yet. Status promoted PLANNED -> INTEGRATED 2026-05-25 — dedicated chorio seed manifest now authored (prisma/seed/manifests/ob.chorioamnionitis.v1.ts), so the audit manifest-pointer requirement is satisfied. Promotion only added the manifest pointer + flipped status; dossier clinical content, citations, RxCUIs, design brief, and workups were already complete + live-verified (2026-05-25) and were not re-touched.

Entry points (7)

  • vital_abnormality
    Intrapartum maternal fever — single ≥ 39.0 °C OR 38.0-38.9 °C confirmed × 2 ≥ 30 min apart (Higgins NICHD/ACOG/SMFM 2016 Obstet Gynecol 127:426)
    intrapartum_maternal_fever
  • symptom
    Sustained fetal heart rate > 160 bpm for ≥ 10 min on continuous EFM with maternal fever (Higgins 2016; ACOG CO 712 2017)
    fetal_tachycardia_sustained
  • lab_abnormality
    Maternal WBC > 15,000/µL without antenatal corticosteroid exposure + maternal fever (Higgins 2016)
    maternal_leukocytosis_without_steroids
  • symptom
    Purulent / foul cervical discharge on speculum exam with maternal fever (Higgins 2016)
    purulent_cervical_discharge
  • symptom
    Uterine tenderness on palpation with maternal fever — supportive but not in Higgins 2016 criteria; common in classic clinical chorioamnionitis (Newton 1993)
    uterine_tenderness_with_fever
  • lab_abnormality
    Amniotic fluid Gram stain positive OR glucose < 14 mg/dL OR culture positive (confirmed Triple I per Higgins 2016)
    amniotic_fluid_gram_stain_positive_or_low_glucose
  • history
    Prolonged ROM > 18 h with subsequent maternal fever — high-pretest cohort (ACOG PB 188 2018)
    prolonged_rom_with_fever

Required inputs (20)

  • maternal_temperaturerequired
    vital • used at ENTRY
    Single ≥ 39.0 °C OR 38.0-38.9 °C × 2 ≥ 30 min apart is the gateway criterion (Higgins 2016)
  • maternal_hrrequired
    vital • used at CONTEXT
    Maternal tachycardia > 100 is a Triple I supportive criterion (legacy chorio criteria; reduced sensitivity in Higgins 2016)
  • maternal_bprequired
    vital • used at RED_FLAGS
    Hypotension is a sepsis flag — drives routing to id.sepsis.core.v1; MAP < 65 in pregnant patient demands rapid resuscitation (SSC 2026 with OB adaptation)
  • maternal_rrrequired
    vital • used at CONTEXT
    Tachypnea > 22 is qSOFA component; pregnant baseline ~ 16-22 so > 24 is concerning (SSC 2026)
  • maternal_spo2required
    vital • used at CONTEXT
    Hypoxemia in pregnancy raises suspicion for atypical sepsis (pulmonary embolism mimic, AFE) or pneumonia source (separate dx)
  • fetal_heart_rate_baselinerequired
    vital • used at CONTEXT
    FHR > 160 sustained × 10 min is Higgins 2016 suspected Triple I criterion; informs delivery urgency
  • gestational_age_weeksrequired
    demographic • used at FRAME
    Term ≥ 37 wk (~ 2-5% chorio incidence) vs preterm < 37 wk (~ 25% chorio incidence in preterm labor); preterm chorio drives neonatal NICU planning + steroid + magnesium decisions
  • rom_duration_hoursrequired
    history • used at CONTEXT
    ROM > 18 h is a CDC IAP indication + chorio risk factor; drives empiric antibiotic timing decision
  • number_of_cervical_examsrequired
    history • used at CONTEXT
    Repeated cervical exams after ROM increase ascending-infection risk dose-response (Newton 1993; Tita Andrews 2010)
  • maternal_gbs_status_and_iaprequired
    history • used at CONTEXT
    GBS-positive antepartum screen with inadequate or no intrapartum prophylaxis raises neonatal EOS risk; informs newborn pathway per CDC Verani 2010 + AAP Puopolo 2018
  • maternal_pen_allergy_severityrequired
    history • used at TREATMENT
    Anaphylaxis vs mild allergy drives substitute regimen: anaphylaxis → vancomycin + gentamicin; mild → cefazolin + gentamicin (ACOG CO 712 2017; ACOG CO 797 2020)
  • delivery_mode_plannedrequired
    history • used at TREATMENT
    Cesarean vs vaginal drives anaerobic coverage decision (clindamycin or metronidazole add-on for cesarean to prevent postpartum endometritis)
  • prior_chorio_in_prior_pregnancy
    history • used at CONTEXT
    Recurrent chorio in subsequent pregnancy informs surveillance + microbiome considerations; not a treatment modifier per se
  • maternal_cbc_with_diffrequired
    lab • used at INITIAL_WORKUP
    WBC > 15K without steroids is Higgins 2016 suspected Triple I criterion; baseline + trend in postpartum endometritis surveillance
  • maternal_blood_culture
    lab • used at INITIAL_WORKUP
    Bacteremia in chorio ~ 5-10%; mandatory if SIRS / qSOFA features (sepsis pathway carryover)
  • maternal_urine_culturerequired
    lab • used at INITIAL_WORKUP
    Pyelonephritis is a common chorio mimic in pregnancy — rule out with UA + urine culture
  • maternal_lactate
    lab • used at INITIAL_WORKUP
    Lactate > 2 with infection is a sepsis flag; drives routing to id.sepsis.core.v1 (SSC 2026 Hour-1 bundle)
  • maternal_metabolic_panelrequired
    lab • used at INITIAL_WORKUP
    Renal function for dosing + sepsis organ dysfunction (creatinine ≥ 2× baseline → KDIGO AKI; sepsis-AKI cross-reference)
  • amniotic_fluid_studies_if_amniocentesis
    lab • used at BRANCHING_WORKUP
    Amniotic fluid Gram stain, culture, glucose < 14 mg/dL, IL-6 elevated define confirmed Triple I (Higgins 2016); amniocentesis rare intrapartum but used selectively
  • maternal_cxr_if_pulmonary_features
    imaging • used at BRANCHING_WORKUP
    Rule out pneumonia source (community-acquired or aspiration) if cough / desaturation / focal exam (separate dx pathway via pulm.cap.core.v1)

12-phase flow (12)

  1. 1FRAME
    Intrapartum / immediate-postpartum maternal infection-inflammation syndrome; renamed "Triple I" per Higgins NICHD/ACOG/SMFM 2016 + ACOG CO 712 2017. Partition by gestational age: term (≥ 37 wk, ~ 2-5% incidence) vs preterm (< 37 wk, ~ 25% incidence in preterm labor). Distinguishes from isolated maternal fever (single criterion; observe + investigate other causes) vs suspected Triple I (fever + ≥ 1 secondary criterion; empiric antibiotics) vs confirmed Triple I (with objective amniotic fluid evidence).
    inputs: gestational_age_weeks
    advance: GA cohort tagged; Higgins 2016 diagnostic category assigned
  2. 2ENTRY
    Recognise via intrapartum maternal fever (single ≥ 39.0 °C OR 38.0-38.9 °C × 2 ≥ 30 min) ± secondary criteria (FHR > 160 sustained, WBC > 15K without steroids, purulent cervical discharge). Differentiate from isolated maternal fever (single criterion only) per Higgins 2016.
    inputs: maternal_temperature
    advance: Diagnostic category (isolated fever / suspected / confirmed Triple I) assigned
  3. 3CONTEXT
    Gestational age, ROM duration, number of cervical exams, GBS status + IAP adequacy, maternal pen allergy severity (anaphylaxis vs mild), planned delivery mode (cesarean vs vaginal), prior chorio history, maternal comorbidities (DM, HIV, hypothyroidism, immunosuppression).
    inputs: gestational_age_weeks, rom_duration_hours, number_of_cervical_exams, maternal_gbs_status_and_iap, maternal_pen_allergy_severity, delivery_mode_planned, maternal_hr, maternal_rr, maternal_spo2, fetal_heart_rate_baseline
    advance: Risk-factor profile + setting + delivery-plan context captured
  4. 4RED_FLAGS
    Maternal sepsis features (qSOFA ≥ 2: SBP ≤ 100, RR ≥ 22, AMS; OR lactate ≥ 2 with infection; SSC 2026 OB adaptation) → routes to id.sepsis.core.v1 with chorio carryover. Severe Triple I with shock / pulmonary edema / multi-organ dysfunction → ICU + emergent delivery + broad-spectrum.
    inputs: maternal_bp, maternal_temperature
    actions: protocol.septic_shock
    advance: Sepsis-pathway routing decision documented; ICU triage if severe
  5. 5INITIAL_WORKUP
    Maternal CBC with diff (Higgins 2016 WBC > 15K), CMP, blood culture if SIRS features, urine culture (pyelonephritis ddx), lactate if sepsis features, baseline coag if cesarean planned. Continuous fetal monitoring (Category I / II / III interpretation). Amniotic fluid studies only if amniocentesis already performed (not routinely).
    inputs: maternal_cbc_with_diff, maternal_urine_culture, maternal_metabolic_panel
    actions: workup.fuo, panel.cbc, panel.renal, panel.coag, panel.ua
    advance: Labs drawn; fetal monitoring established; empiric antibiotics administered
  6. 6BRANCHING_WORKUP
    Maternal CXR if pulmonary features (pneumonia ddx); blood cultures if persistent fever despite antibiotics; pelvic US for retained products if postpartum chorio differential; placental pathology after delivery (gold standard confirmed Triple I diagnosis).
    inputs: maternal_blood_culture, maternal_lactate, maternal_cxr_if_pulmonary_features, amniotic_fluid_studies_if_amniocentesis
    actions: workup.crbsi
    advance: Source identified or empirically covered; placental pathology arranged
  7. 7DIFFERENTIAL
    Pyelonephritis (UA + urine culture), influenza (PCR if season), COVID-19 (PCR), appendicitis (atypical RLQ in pregnancy), pneumonia (CXR), DVT / PE (Doppler + d-dimer caveats in pregnancy), epidural-related fever (common with > 4 h labor epidural; non-infectious), drug fever, pre-eclampsia with HELLP (overlap; ALT/AST + platelets + UA protein), amniotic fluid embolism (AFE; sudden hypoxia + hypotension + DIC at delivery — emergent), isolated maternal fever (Higgins 2016 — single criterion alone, not yet Triple I).
    advance: Mimics excluded or co-managed
  8. 8RISK_STRATIFICATION
    Higgins 2016 category (isolated fever / suspected / confirmed Triple I) + maternal SIRS / qSOFA (Sepsis-3) + fetal category (I/II/III non-reassuring) drives delivery urgency: stable + responsive → expedite labor; non-reassuring fetal status + sepsis features → emergent cesarean; severe maternal sepsis + uncorrectable → ICU + emergent delivery. Preterm < 34 wk with chorio + intact membranes is RARE — delivery typically expedited.
    inputs: maternal_bp, maternal_hr, maternal_rr
    actions: calc.sirs, calc.qsofa
    advance: Higgins category + sepsis-severity tier + delivery-urgency tier set
  9. 9TREATMENT
    INTRAPARTUM: ampicillin 2 g IV q6h + gentamicin 1.5 mg/kg IV q8h (or 5 mg/kg q24h once-daily extended-interval — ACOG CO 712 2017). PEN-ALLERGIC anaphylaxis → vancomycin 1 g IV q12h + gentamicin. MILD pen allergy → cefazolin 2 g IV q8h + gentamicin. ADD anaerobic cover (clindamycin 900 mg IV q8h OR metronidazole 500 mg IV q8h) if CESAREAN delivery planned/performed (postpartum endometritis prevention). DELIVERY is the definitive treatment — do NOT delay for antibiotics; deliver expeditiously AFTER first antibiotic dose. POSTPARTUM: continue antibiotics × 24 h after delivery if vaginal + afebrile + uncomplicated; 48 h if cesarean; longer if persistent fever / sepsis / endometritis emergence. Acetaminophen 1 g PO/IV q6h for maternal fever (avoid NSAIDs intrapartum). IV crystalloid maintenance + fluid balance (avoid overload — pulmonary edema risk in chorio + pre-eclampsia overlap).
    inputs: delivery_mode_planned, maternal_pen_allergy_severity
    advance: Antibiotics in within 1 h of recognition; delivery plan + timeline set; postpartum duration + transition plan documented
  10. 10DISPOSITION
    L&D / labor room for most stable patients; ICU for sepsis-features-severe or post-emergent-cesarean-with-shock; postpartum recovery → mother-baby unit if uncomplicated; OB-step-down or ICU if postpartum sepsis emerging. Newborn pathway: term well → newborn nursery with q4h observation 36-48 h (Kaiser EOS calculator); preterm OR ill OR maternal-chorio-with-additional-risk → NICU + neonatal sepsis empirics per AAP Puopolo 2018.
    inputs: maternal_bp, maternal_spo2
    advance: Maternal level of care set; newborn pathway initiated
  11. 11MONITORING
    Intrapartum: continuous EFM (Category I/II/III), maternal vitals q15 min, fetal scalp pH if Category III, response to antipyretic + antibiotics. Postpartum: vitals q4h × 24 h then per protocol, fundal tone q4h (atony risk elevated in chorio), lochia + uterine tenderness assessment q4h (endometritis surveillance), CBC + CMP daily until afebrile, repeat blood culture at 48-72 h if persistent fever, lactation support, VTE prophylaxis once postpartum bleeding stable.
    inputs: maternal_temperature, maternal_cbc_with_diff
    actions: panel.cbc, panel.renal
    advance: Maternal afebrile × 24 h + improving + tolerating diet + appropriate lochia + responsive newborn evaluation
  12. 12FOLLOWUP
    Routine 6-week postpartum visit + chorio-specific anticipatory guidance: recurrence risk in subsequent pregnancy (~ 5-15%), microbiome / vaginal flora considerations (probiotic + targeted prevention research ongoing), mental health screen (PPD + postpartum-PTSD higher with peripartum complications), breastfeeding support, contraception counseling, immunization review (Tdap if not given, influenza, COVID per ACIP). Newborn outpatient: 24-48 h post-discharge peds visit if maternal chorio (high-risk follow-up).
    advance: Postpartum visit documented; future-pregnancy counseling delivered; newborn followup arranged