S1634 Feasibility of Intestinal Ultrasound in Pregnant Patients with IBD: A Safe and Reliable Modality for Disease Monitoring ACG Outstanding Research Award in the IBD Category

Introduction: Intestinal ultrasound (IUS) is a non-invasive tool for assessing inflammatory bowel disease (IBD) and is particularly valuable in pregnant patients where blood markers may be unreliable and endoscopy or cross-sectional imaging are frequently avoided. IUS enables real-time evaluation of bowel wall thickness and vascularity. However, existing literature highlights inherent limitations, including reduced sensitivity for rectal assessment and reduced visualization of the sigmoid colon and terminal ileum, particularly as gestational age advances. Methods: All IUS performed in pregnant patients with IBD were retrospectively identified through the electronic medical record. Variables relevant to the feasibility of IUS were analyzed, including gestational age, body mass index (BMI), IBD subtype and known disease location, and segmental visualization rates were obtained. Univariate analysis was conducted to evaluate associations between visualization limitations and IBD subtype, trimester of gestation, and BMI. Results: A total of 40 IUS scans were identified. Median gestational age at IUS was 24 weeks (IQR: 19-31) and median BMI at IUS was 27 Kg/m2 (IQR: 25-30). The most common IBD subtype was Crohn’s disease (CD) (60%), followed by ulcerative colitis (UC) (37.5%), and indeterminate colitis (2.5%). Ileo-colonic and pancolitis were the most common disease locations for CD and UC, respectively. The previously known disease locations were visualized in 95% of IUS. The visualization rate per segment from the descending colon to terminal ileum/neo-terminal ileum was 100%, the remaining segments had a visualization rate of 98% for sigmoid colon, 87% for rectum, and 85% for proximal small bowel. A total of 11 IUS scans had limitations in visualizing ≥1 segment; these limitations were not significantly associated to IBD subtype, BMI, or trimester of gestation. Sub-analysis by segment of limitation revealed a significant association between proximal small bowel limitations and trimester of gestation (P = 0.015). Conclusion: IUS proved to be a safe, non-invasive, and reliable tool for segmental visualization and monitoring of IBD during pregnancy in our cohort. There were no major limitations associated with the study across all patient and pregnancy characteristics, differing from the literature. In our cohort, the only segmental limitation significantly associated with trimester of gestation was the proximal small bowel.