What is the management approach for a pregnant patient with neutrophilia and lymphocytopenia?

Elevated Neutrophils and Low Lymphocytes in Pregnancy

Elevated neutrophils with low lymphocytes during pregnancy is a normal physiological finding that requires no intervention unless accompanied by clinical signs of infection, systemic illness, or extreme values (WBC >20 × 10⁹/L).

Normal Physiological Changes in Pregnancy

Pregnancy induces predictable leukocyte changes that peak during the second trimester and persist through delivery:

• Neutrophil-to-lymphocyte ratio (NLR) increases progressively: Mean NLR values are 2.6±1.0 in the first trimester, 4.0±1.4 in the second trimester, and 3.5±1.2 in the third trimester 1
• Lymphocyte counts physiologically decrease as neutrophils rise, creating the pattern of neutrophilia with relative lymphocytopenia 1
• This represents normal immunoregulation during pregnancy and does not indicate pathology in asymptomatic patients 2

When to Investigate Further

Investigate only if any of the following red flags are present:

• WBC count exceeds 20 × 10⁹/L persistently, which is rare and warrants hematologic evaluation 2
• Fever, constitutional symptoms, or signs of infection suggesting bacterial sepsis or other infectious process 3
• Concurrent thrombocytopenia (platelets <100 × 10⁹/L), which may indicate preeclampsia, HELLP syndrome, immune thrombocytopenia, or thrombotic microangiopathy 4, 5
• Hepatic dysfunction, hemolysis, or renal impairment suggesting preeclampsia/HELLP or other systemic disorders 3
• Persistent fever with hepatosplenomegaly and cytopenias raising concern for hemophagocytic lymphohistiocytosis, which requires ferritin >500 ng/mL and bone marrow evaluation 6

Management Algorithm

For asymptomatic patients with isolated neutrophilia and lymphocytopenia:

1. No treatment required - this is physiological 1
2. Document baseline complete blood count for comparison if clinical changes occur 2
3. Reassure the patient that these changes normalize postpartum, typically within 24-48 hours of delivery 2

For symptomatic patients or those with extreme leukocytosis (WBC >20 × 10⁹/L):

1. Rule out infection first: Blood cultures, urinalysis, chest imaging if respiratory symptoms present 2
2. Assess for preeclampsia: Blood pressure, proteinuria, liver enzymes, platelet count 3
3. Consider hematologic consultation if leukocytosis persists >2 weeks without identified cause or if atypical features present (blasts, immature cells) 2
4. Avoid empiric antibiotics unless clear infectious source identified, as pregnancy-induced leukocytosis will not respond to antimicrobials 2

Common Pitfalls to Avoid

• Do not treat physiological leukocytosis with antibiotics - this is ineffective and exposes the patient to unnecessary medication risks 2
• Do not assume infection based solely on elevated neutrophils - pregnancy itself causes neutrophilia up to 15-20 × 10⁹/L without pathology 1
• Do not overlook thrombocytopenia - the combination of leukocytosis with low platelets suggests preeclampsia, HELLP, or other serious conditions requiring immediate evaluation 4, 5
• Do not delay delivery if malignant leukocytosis confirmed - pregnancy termination is the definitive treatment for pregnancy-induced leukocytosis that persists despite investigation 2

Postpartum Resolution

Neutrophil counts normalize rapidly after delivery:

• Most patients return to baseline within 24 hours postpartum 2
• If leukocytosis persists beyond 48 hours postpartum, investigate for retained products, endometritis, or underlying hematologic disorder 2