Active inflammatory bowel disease detected by intestinal ultrasound during pregnancy is strongly associated with adverse maternal and neonatal outcomes, even when clinical scores suggest remission, according to the large international PICCOLO-X study published in Gastroenterology. Conducted from 2017 to 2023 at St Vincent’s Hospital Melbourne, Monash Health in Australia, and Mount Sinai in New York, the study followed 377 pregnant women with IBD, of whom 234 underwent intestinal ultrasound and 331 provided fecal calprotectin samples.
Researchers found that maximal bowel wall thickness greater than 6 mm in the second trimester was linked to a fourfold increased risk of preterm delivery and a twofold increased risk of low birth weight. Each additional millimeter of bowel wall thickness in the second trimester was also associated with a higher risk of gestational diabetes.
Hyperemia detected on ultrasound correlated with a threefold increase in the risk of preeclampsia. Intestinal ultrasound often revealed active disease that clinical scores or fecal calprotectin failed to detect. In the first trimester, 16% of women who appeared to be in remission by calprotectin had active disease on ultrasound, most commonly ileal Crohn’s disease. A similar discordance was observed in the second trimester.
Clinical outcomes reflected these findings: 5.9% of participants delivered prematurely, 5.8% of infants had low birth weight, and nearly one-quarter required neonatal intensive or special care admission. Among women with objective disease activity in the first trimester, treatment was escalated in 20 cases, and one-quarter of those achieved both biochemical and sonographic remission by the second trimester.
Of the cohort, 198 participants had Crohn’s disease and 171 had ulcerative colitis or IBD-unclassified, with more than half receiving advanced therapy during pregnancy. Rates of treatment exposure were similar regardless of ultrasound disease activity, noted Ralley E. Prentice, FRACP, of the Department of Gastroenterology, Monash Health, Victoria, Australia, and colleagues.
Ultrasound proved feasible but not without challenges: median gestational age at scanning was 11 weeks in the first trimester and 20 weeks in the second trimester, and image quality was compromised in 6.7% of first trimester and 22.3% of second-trimester scans, primarily due to gravid uterus or maternal body habitus. The authors emphasized that reliance on endoscopy or MRI during pregnancy is limited by safety and convenience, making ultrasound a valuable tool.
"We rely very little on symptoms in pregnancy—they’re so unreliable—and instead target fecal calprotectin under 100 and sonographic remission," said lead author Dr. Prentice in an interview with Conexiant.
"The routine use of endoscopy or magnetic resonance imaging during pregnancy is limited by inconvenience and safety concerns," noted investigators. Findings showed poor agreement between clinical scoring systems and objective measures of disease activity.
Limitations included relatively low numbers of adverse outcomes, variable protocol adherence, and incomplete data acquisition due to late pregnancy referrals. Approximately half of participants were assessed with all three disease activity methods in the first and second trimesters.
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Source: Gastroenterology
