Neutrophil Count (whole blood)
Neutrophils rise progressively during pregnancy due to physiologic immune activation and increased corticosteroid influence.
| Units | Nonpregnant Adult | 1st Trimester | 2nd Trimester | 3rd Trimester |
|---|---|---|---|---|
| ×10³/mm³ ×10³/µL |
1.4 – 4.6 | 3.6 – 10.1 | 3.8 – 12.3 | 3.9 – 13.1 |
| ×10⁹/L | 1.4 – 4.6 | 3.6 – 10.1 | 3.8 – 12.3 | 3.9 – 13.1 |
Pregnancy physiology
- Significant physiologic neutrophilia is normal in pregnancy.
- Neutrophil counts may double baseline values by the third trimester.
- Mechanism includes increased cortisol, elevated cytokines, and demargination.
- Neutrophil function remains intact.
Causes of elevated neutrophil count (neutrophilia)
- Normal pregnancy (most common)
- Acute bacterial infection
- Stress response (trauma, surgery, seizure)
- Corticosteroid therapy
- Smoking
- Hemorrhage / hemolysis
- Myeloproliferative disorders (CML, polycythemia vera)
Cited references:
• Abbassi-Ghanavati et al., Obstet Gynecol 2009.
• Bain BJ. Blood Cells—A Practical Guide.
• Williams Hematology.
Causes of decreased neutrophil count (neutropenia)
- Viral infections (EBV, HIV, hepatitis)
- Autoimmune neutropenia / SLE
- Drug-induced (antithyroid meds, antibiotics, anticonvulsants)
- Aplastic anemia / marrow failure
- Chemotherapy or radiation
- Severe sepsis (consumption)
- Nutritional deficiency (B12, folate, copper)
Cited references:
• Williams Hematology.
• Hoffman R. Hematology: Basic Principles and Practice.
• Bain BJ — Leukocyte disorders.
References
- Abbassi-Ghanavati M, Greer LG, Cunningham FG. Pregnancy and laboratory studies: a reference table for clinicians. Obstet Gynecol. 2009;114:1326-31.
- Bain BJ. Blood Cells: A Practical Guide. Wiley-Blackwell.
- Williams Hematology, 10th ed.