From the Research
The normal white blood cell (WBC) count during pregnancy typically increases to a range of 5.7-15.0×10^9/L, with a 36% increase in total WBC count, driven by a 55% increase in neutrophils and 38% increase in monocytes. This increase in WBC count is a normal adaptation to pregnancy, and is primarily driven by physical and hormonal changes, including elevated estrogen and progesterone levels, which stimulate bone marrow to produce more white blood cells 1. The WBC count can be used as a predictor of the severity of sickle cell disease in pregnancy, with higher WBC counts associated with an increased risk of pregnancy-related complications 2. However, it is essential to interpret WBC results in the context of normal pregnant physiology, using a pregnancy-specific reference interval until delivery, and between days 7-21 after childbirth 1. Some studies have reported different reference intervals for WBC counts during pregnancy, but the most recent and highest quality study suggests that the upper reference limit for total WBC is elevated by 36% in pregnancy, with a reference interval of 5.7-15.0×10^9/L 1. Key points to consider when evaluating WBC counts during pregnancy include:
- The normal range of WBC count during pregnancy is 5.7-15.0×10^9/L
- The WBC count increases by 36% during pregnancy, driven by a 55% increase in neutrophils and 38% increase in monocytes
- The WBC count can be used as a predictor of the severity of sickle cell disease in pregnancy
- It is essential to interpret WBC results in the context of normal pregnant physiology, using a pregnancy-specific reference interval until delivery, and between days 7-21 after childbirth.