What are the diagnostic criteria and management for sepsis in the puerperal (postpartum) period?

Diagnostic Criteria for Sepsis in the Puerperal Period

For puerperal sepsis diagnosis, use a two-step approach: first screen with obstetrically modified SIRS (omSIRS) criteria, then confirm with evidence of end-organ injury using pregnancy-specific thresholds that account for normal physiologic changes of the postpartum period. 1

Screening: Obstetrically Modified SIRS (omSIRS)

The California Maternal Quality Care Collaborative (CMQCC) recommends using omSIRS as the initial screening tool, which requires suspected or confirmed infection PLUS at least 2 of the following: 1

• Temperature >38°C or <36°C 1
• Heart rate >100 beats/min (modified from standard >90 bpm to account for pregnancy) 1
• Respiratory rate >20 breaths/min 1
• White blood cell count >12,000 or <4,000 cells/μL, or >10% bands 1

Critical timing consideration: Approximately half of puerperal sepsis cases occur in the post-discharge period, making outpatient recognition equally important as inpatient screening. 1

Diagnosis: End-Organ Injury Criteria

Only ONE criterion is required for diagnosis of maternal sepsis once omSIRS screen is positive. The criteria differ based on timing postpartum: 1

For 0-3 Days Postpartum (Obstetrically Modified Criteria):

• Hypotension: SBP <85 mmHg (note: lower than standard <90 mmHg), OR MAP <65 mmHg, OR >40 mmHg decrease in SBP 1
• Respiratory failure: New need for invasive or non-invasive mechanical ventilation 1
• Coagulopathy: Platelets <100 × 10⁹/L, OR INR >1.5, OR PTT >60 seconds 1
• Hepatic dysfunction: Total bilirubin >2 mg/dL 1
• Renal dysfunction: Creatinine >1.2 mg/dL (lower threshold than standard >2.0 mg/dL), OR urine output <0.5 mL/kg/hour for 2 consecutive hours 1
• Elevated lactate: >2 mmol/L (excluding during active labor, though still requires close monitoring) 1
• Altered mental status: Agitation, confusion, or unresponsiveness 1

For >3 Days Postpartum (Standard Criteria):

• Hypotension: SBP <90 mmHg (standard threshold returns), OR MAP <65 mmHg, OR >40 mmHg decrease in SBP 1
• Respiratory failure: New need for mechanical ventilation 1
• Coagulopathy: Platelets <100 × 10⁹/L, OR INR >1.5, OR PTT >60 seconds 1
• Hepatic dysfunction: Total bilirubin >2 mg/dL 1
• Renal dysfunction: Creatinine >2.0 mg/dL, OR urine output <0.5 mL/kg/hour for 2 consecutive hours 1
• Elevated lactate: >2 mmol/L 1
• Altered mental status: Agitation, confusion, or unresponsiveness 1

Septic Shock Definition

Septic shock is diagnosed when severe sepsis criteria are met PLUS one of the following persists after fluid resuscitation: 1

• Persistent hypotension (using gestational age-appropriate thresholds above) 1
• OR Lactic acid >4 mmol/L 1

Critical Pitfalls and Caveats

High false-positive rate with chorioamnionitis/endometritis: These patients frequently trigger omSIRS screening but may not have true sepsis. Initiate appropriate antibiotics promptly and monitor closely, escalating care only if the patient fails to respond to initial treatment. 1

Lactic acid interpretation during labor: Elevated lactate during active labor and immediately postpartum is physiologic and should NOT be used for diagnosis, though it remains important for treatment guidance and requires follow-up. 1

White blood cell count after corticosteroids: WBC peaks 24 hours after betamethasone administration (2 SD from mean is 20.8 × 10⁶/L) and returns to baseline by 96 hours. A WBC obtained within 24 hours can still be used for initial screening. 1

Physiologic changes mask sepsis: Normal pregnancy and postpartum physiology (increased heart rate, respiratory rate, decreased blood pressure) can obscure early sepsis signs, requiring high clinical suspicion. 2

Three-Stage Approach for Clinical Implementation

The most recent guidelines propose a structured framework: 1

1. Stage 1: Initial alert for suspected infection
2. Stage 2: omSIRS screening (as detailed above)
3. Stage 3: Bedside evaluation for end-organ injury with immediate initiation of sepsis bundles if criteria met

This approach aligns with CMS SEP-1 requirements, which transition to pay-for-performance metrics in fiscal year 2026. 1

Management Priorities

Sepsis is a medical emergency requiring immediate treatment: 3, 4

• Antibiotics within 1 hour of recognition for high-risk patients 1, 4
• Crystalloid resuscitation: 30 mL/kg (1-2 L) within first 3 hours for hypotension or suspected hypoperfusion 1, 4
• Obtain cultures (blood, urine, others as indicated) before antibiotics if no substantial delay 4
• Measure lactate immediately and repeat within 6 hours if elevated 1
• Norepinephrine as first-line vasopressor if hypotension persists despite fluids 1, 4
• Source control: If uterine source suspected, prompt delivery or evacuation regardless of gestational age 4

Delivery is NOT indicated for sepsis alone—obstetric indications should guide timing unless the uterus is the infection source. 3