Intestinal Ultrasound to Evaluate Treatment Response During Pregnancy in Patients With Inflammatory Bowel Disease

Introduction: Active disease in inflammatory bowel disease patients during pregnancy is associated with poor maternal and fetal outcomes. Objective evaluation of disease activity is a core strategy in IBD, and during pregnancy noninvasive modalities are preferred. We aimed to evaluate feasibility and accuracy of intestinal ultrasound (IUS) to objectify disease activity throughout pregnancy. Methods: Pregnant patients with known IBD were included and followed throughout pregnancy for clinical disease activity, with fecal calprotectin (FCP) and with IUS every trimester. Feasibility of IUS was assessed for all colonic segments and terminal ileum (TI). Intestinal ultrasound outcomes to detect active disease and treatment response were compared with clinical scores combined with FCP. Results: In total, 38 patients (22 CD, 16 UC) were included, with 27 patients having serial IUS. Feasibility of IUS decreases significantly in third trimester for TI (first vs third trimester: 91.3% vs 21.7%, P <. 0001) and sigmoid (first vs third trimester: 95.6% vs 69.5%, P =. 023). Intestinal ultrasound activity showed moderate to strong correlation with clinical activity (r=0.60, P <. 0001) and FCP (r=0.73, P <. 0001). Throughout pregnancy, IUS distinguished active from quiescent disease with 84% sensitivity and 98% specificity according to FCP combined with clinical activity. IUS showed disease activity in >1 segment in 52% of patients and detected treatment response with 80% sensitivity and 92% specificity. Conclusions: IUS is feasible and accurate throughout pregnancy, although visualization of the sigmoid and TI decreases in the third trimester. IUS provides objective information on disease activity, extent, and treatment response, even during second and third trimester, and offers a noninvasive strategy to closely monitor patients during pregnancy.