Introduction: Management of inflammatory bowel diseases (IBDs)-both Crohn's disease (CD) and ulcerative colitis (UC)-during pregnancy can be challenging since most monitoring tools available in nonpregnant patients are contraindicated. Objectives: The aim of the study was to test whether fecal inflammatory markers-specifically fecal lactoferrinphysiologically change during normal pregnancy as a prerequisite to use them to monitor IBD activity during pregnancy. Methods: Fecal lactoferrin was tested in healthy pregnant and nonpregnant women from the same geographic area and age range (18-40 years)-all negative for clinical gastrointestinal tract inflammation. A retrospective review of fecal lactoferrin levels contrasted with the Simple Endoscopic Score for CD, and the Disease Activity Index for UC was also performed in women with active IBDs within the same age range and geographical area. Results: In 30 nonpregnant subjects, fecal lactoferrin levels were 0.87 ± 1.08 μg/g. In 49 pregnant subjects, levels were 0.59 ± 0.83, 0.87 ± 1.13, and 0.85 ± 1.06 μg/g during the first, second, and third trimester, respectively (p = 0.64), with average levels for the 3 trimesters of 0.81 ± 1.04 μg/g (p = 0.61 compared to nonpregnant subjects). Sequential fecal lactoferrin levels (n = 26) did not differ from one trimester to the other in the individual subjects (p = 0.80). In 45 female IBD patients (27 with CD and 18 with UC), fecal lactoferrin levels were correlated with disease activity as defined by the endoscopic scores: 218, 688, and 1,175 μg/g for CD and 931, 2,088, and 2,509 μg/g for UC, respectively, for mild, moderate, and severe activity. Conclusions: Fecal lactoferrin levels during normal pregnancy are superimposable to those of nonpregnant women and significantly below levels in women of the same childbearing age with active IBDs. Additional published data-reviewed in this atricle-and our own indicate that fecal lactoferrin and other markers can be potentially used to monitor disease activity in pregnant IBD patients.