Reference Intervals for Fecal Calprotectin in Pregnant Women Using a Particle Enhanced Turbidimetric Assay

Background: Fecal calprotectin is widely used as a marker for inflammatory bowel diseases (IBD). IBD often affects women during their reproductive years, but there are no established reference intervals during pregnancy. The aim of the present study was to define reference values during pregnancy and in the postpartum period to allow comparisons between patient results and reference values. Methods: Fecal samples were collected from 84 healthy females during pregnancy week 26 to 28 and a second sample was collected six months after delivery. The samples were weighed, extracted, and centrifugated to remove debris. The extracted samples were then analyzed on a chemistry analyzer using a particle enhanced turbidimetric immunoassay reagent. Results: The calculated reference interval during pregnancy was < 127 mu g/g (90% confidence interval, 90 -164 mu g/g) and the corresponding reference interval during the postpartum period was < 143 mu g/g (60 -226 mu g/g). There were no significant statistical differences between F-calprotectin values analyzed at the two sampling times. Conclusions: The reference values are slightly higher than the cutoff values of 50 - 100 mu g/g often used as general cutoff for fecal calprotectin.