Corticosteroid-induced leukocytosis in pregnancy: A prospective observational study

In the course of managing preterm labour, increasing trends of total white cell count raises concern for the obstetrician, suggesting a possible underlying infectious aetiology. Although mild leukocytosis is expected in pregnancy, the patterns of increment after corticosteroid administration are not well described beyond animal models and in a small number of human studies.

Seventy-three consecutive patients who required antenatal corticosteroids for either preterm labour or prelabour caesarean section were recruited and given a standard course of 12mg dexamethasone phosphate, twelve hours apart. Venous blood samples were taken before administration, at six hours and 36 hours after the first dose of dexamethasone.

The total white count trend was 10.31±2.62 at baseline, 11.44±3.05 at six hours and 12.20±3.49 at 36 hours. Neutrophil-lymphocyte ratio was 3.60±1.31, 8.73±3.63 and 3.24±1.49 respectively, reflecting relative neutrophilia and lymphopenia which normalised by 36 hours.

In contrast to previous studies, we found only a slight increment in total white cell count of about 10%. The marginal changes described in our study would not normally raise any clinical concern, although vigilance should be exercised if higher levels were observed.