From the Guidelines
Yes, it is expected to see an elevated WBC and neutrophil count in pregnancy. The WBC count typically increases progressively throughout pregnancy, with values commonly ranging from 9,000 to 15,000 cells/μL, compared to the non-pregnant normal range of 4,000 to 10,000 cells/μL. This increase is primarily due to neutrophilia (elevated neutrophil count), which can represent up to 80-90% of the total WBC count in pregnant women. However, the provided evidence does not directly address the question of WBC and neutrophil count in pregnancy, as it focuses on D-dimer levels and COVID-19 coagulopathy in pregnancy 1. Despite the lack of direct evidence, it is well-established in medical literature that physiological leukocytosis occurs as part of normal pregnancy adaptation, caused by increased inflammatory mediators, elevated estrogen levels, and the body's response to the physical stress of pregnancy. Some key points to consider include:
- The neutrophil increase helps protect both mother and fetus from infection while supporting placental development.
- During labor and immediate postpartum, WBC counts can temporarily spike even higher, sometimes reaching 20,000-30,000 cells/μL.
- Healthcare providers should be aware of these normal pregnancy changes when interpreting laboratory results to avoid misdiagnosing infection or inflammation.
From the Research
White Blood Cell Count in Pregnancy
- The white blood cell (WBC) count is known to increase during pregnancy, with studies indicating a significant rise in WBC count, primarily driven by an increase in neutrophils 2, 3.
- The upper reference limit for total WBC count is elevated by 36% in pregnancy, with a 55% increase in neutrophils 2.
- The WBC count exhibits a rapid rise before 7 weeks of gestation, followed by a plateau, with neutrophils primarily driving this increase 3.
- Reference intervals for WBC counts during pregnancy have been established, with values ranging from 4.0-10.0 × 10^9/L for ≤ 2 weeks, 4.7-11.9 × 10^9/L for 3-5 weeks, and 5.7-14.4 × 10^9/L for ≥ 6 weeks of gestation 3.
Neutrophil Count in Pregnancy
- Neutrophils comprise a significant proportion of the leukocyte count in pregnant women, with studies indicating an increase in neutrophil count during pregnancy 2, 3.
- The neutrophil count is elevated in pregnant women, with a 55% increase reported in one study 2.
- The proportion of parturients with a neutrophil count of ≥ 80% of the leukocyte count is higher in febrile parturients (57.6%) compared to non-febrile parturients (30.6%) 4.
Clinical Implications
- Elevated WBC and neutrophil counts are common in pregnancy and should be interpreted using pregnancy-specific reference intervals 2, 3.
- Monitoring WBC counts is clinically relevant, as elevated levels are associated with an increased risk of infection and pregnancy-related complications 3.
- The diagnostic value of WBC counts and other laboratory variables, such as C-reactive protein, should be considered when evaluating patients for antibiotic treatment 5.