Does Pre-eclampsia Cause White Blood Cell Count to Increase?
Yes, pre-eclampsia is associated with elevated white blood cell (WBC) counts as part of a systemic inflammatory response that characterizes this disorder.
Inflammatory Nature of Pre-eclampsia
Pre-eclampsia fundamentally represents an excessive maternal inflammatory response to pregnancy, involving activation of multiple inflammatory pathways 1, 2. The condition is characterized by:
- Leukocyte activation as a core feature of the systemic inflammatory response 1
- Intravascular inflammation involving white blood cells, endothelial cells, and the clotting cascade 2
- Neutrophil and lymphocyte elevation that significantly exceeds levels seen in normal pregnancy 3
The inflammatory response in pre-eclampsia is not a separate phenomenon but rather represents decompensation of the universal maternal inflammatory adaptation to pregnancy 2.
Evidence for Elevated WBC in Pre-eclampsia
Recent research directly demonstrates increased white blood cell parameters in pre-eclamptic patients:
- WBC count is significantly higher in women with pre-eclampsia compared to normal pregnant controls 3
- Neutrophil counts are significantly elevated in the pre-eclampsia group 3
- Lymphocyte counts are also significantly increased 3
A 2024 study found that the systemic immune-inflammation index (which incorporates neutrophil, lymphocyte, and platelet counts) had 77.5% sensitivity and 67.5% specificity for diagnosing pre-eclampsia at a cut-off value of 758.39 × 10⁹/L 3.
Pathophysiological Mechanism
The WBC elevation occurs through a specific cascade:
- Placental oxidative stress from inadequate blood supply triggers release of inflammatory factors into maternal circulation 1
- Syncytiotrophoblast debris and antiangiogenic factors (such as sFlt-1) activate the maternal inflammatory system 1, 4
- Endothelial dysfunction results from this inflammatory activation, creating a feed-forward cycle 1, 2
- Intravascular inflammation involves activation of leukocytes, complement, and coagulation systems 2
Clinical Monitoring Implications
While WBC elevation is characteristic of pre-eclampsia, platelet count monitoring is more clinically critical for management decisions:
- Platelet counts are significantly lower in pre-eclampsia compared to controls 3
- Progressive thrombocytopenia is an indication for delivery at any gestational age 5, 6
- Twice-weekly monitoring of hemoglobin, platelet count, liver enzymes, and renal function is recommended 5, 6
The NHLBI Working Group notes that while activation of the coagulation cascade can be detected in most pre-eclamptic women, consumption of procoagulants sufficient to be detected by standard testing occurs in only about 10% of cases 5.
Important Caveats
- WBC elevation alone is not diagnostic of pre-eclampsia, as normal pregnancy itself involves increased inflammatory markers 2
- The difference between normal pregnancy and pre-eclampsia is quantitative rather than qualitative—pre-eclampsia represents the extreme end of normal maternal inflammatory adaptation 2
- WBC count should not guide delivery decisions; instead, focus on blood pressure control, platelet count, liver/renal function, and fetal status 5, 6
The systemic immune-inflammation index may serve as a helpful adjunctive marker because it simultaneously evaluates neutrophils and lymphocytes (indicating inflammation) along with platelets (indicating coagulopathy) 3.