The multicenter PICCOLO X cohort shows that intestinal ultrasound during pregnancy frequently detects active inflammatory bowel disease despite reassuring symptoms or fecal calprotectin, and that these ultrasound findings strongly predict obstetric risk.

A second trimester maximal bowel wall thickness greater than 6 millimeters was linked to about 4 times higher odds of preterm birth and about 2 times higher odds of low birth weight. Each additional millimeter correlated with greater risk of gestational diabetes, and hyperemia was associated with about 3 times higher odds of preeclampsia.

Discordance was common, with 16% of patients in calprotectin defined remission still showing active disease on ultrasound, often in ileal Crohn’s disease, and this aligned with observed outcomes including 5.9% preterm birth, 5.8% low birth weight, and about 25% admission to neonatal intensive or special care.

Given its feasibility, despite some limitations in image quality, these data support targeting sonographic remission alongside fecal calprotectin below 100 to refine risk stratification and guide therapy in pregnant patients with inflammatory bowel disease, while acknowledging the rarity of events and variability in protocols.