WASHINGTON – Maternal leukocytosis after prenatal corticosteroid administration peaks at up to 24 hours after therapy, with the highest second standard deviation from the mean being 18.3 x 109/L, according to a systematic review and meta-analysis.
There has been limited data available on the magnitude and timing of leukocytosis after corticosteroid administration, making it difficult to interpret the significance of elevated white blood cell counts, Dr. Samuel Bauer, of Beaumont Health, Royal Oak, Mich., said at the annual meeting of the American College of Obstetricians and Gynecologists.
“We know corticosteroids cause leukocytosis, but we haven’t really known what the upper boundary is,” he said.
Driven by concerns about maternal sepsis and the ability to recognize early signs, Dr. Bauer and his colleagues identified six studies that reported white blood cell counts prior to corticosteroid administration, and between 24 and 96 hours afterward in healthy women with singleton gestations. The studies also met the inclusion criterion of having “excluded infected parturients between 23 and 34 weeks of gestation,” he said.
Mean maternal white blood cell count values prior to corticosteroid administration and up to 24 hours, 48 hours, 72 hours, and 96 hours after corticosteroid administration were 10.2, 13.7, 12.8, 11.5, and 11.1 x 109/L, respectively.
The highest second standard deviation from the mean of 18.3 x 109/L did not occur after 24 hours, he emphasized, and by 72 hours, mean values had returned to 11.5 x 109/L.
The findings need to be applied “cautiously” in practice, Dr. Bauer said, since the analysis did not include women with signs of infection and because some women who develop serious infections “have a very low white blood cell count.”
Still, the findings “establish a temporal trend and give us an upper boundary” for the level of leukocytosis that can be expected with prenatal corticosteroids. This can be helpful – along with other considerations – in determining whether an infectious workup is needed when white blood cell counts are high, he said in an interview.
It is not uncommon in clinical practice for maternal leukocytosis at 5-6 days or a week after corticosteroid administration to be attributed to the corticosteroids, he said. But the parameters drawn by this analysis of healthy, non-infected patients show this is a faulty assumption, he added.
The analysis covered 524 patients and 1,406 observations. Dr. Bauer and his coinvestigators did not report any financial disclosures.