Leukocyte blood count during early puerperium and its relation to puerperal infection†

To describe the white blood cell (WBC) and neutrophil counts in early puerperium and to investigate their contribution to the diagnosis of puerperal bacterial infection.

A retrospective cohort analysis through which clinical and laboratory data were collected from 67 695 term live births. Total leukocyte and neutrophil blood count percentiles were established for febrile parturients (FP) with puerperal fever (≥38 °C) and for non-FP (NFP), and stratified by mode of delivery. Rates of positive bacterial cultures were compared according to the total leukocyte and neutrophil blood counts.

Mean WBC counts of parturients delivering vaginally and by cesarean section were 12.62 × 10(3) and 12.71 × 10(3)/µL for NFP, and 14.38 × 10(3) and 12.74 × 10(3)/µL for FP, respectively. The proportions of parturients with a WBC count of ≥15 × 10(3)/µL were 36.4% for FP and 21.8% for NFP (p < 0.001). Neutrophils comprised 80% or more of the leukocyte count in 57.6% of FP and in 30.6% of NFP (p < 0.001). However, no statistically significant differences in the rates of positive bacterial cultures were observed between those with high and low levels of leukocytes and neutrophils.

Leukocytosis and non-extreme neutrophilia were not found to reliably associate with bacterial infection, and their value in determining antibiotic therapy is questioned.