Maternal and Neonatal Outcomes in Women with Inflammatory Bowel Disease Following Different Biologic Utilization Trajectories in Pregnancy

ObjectivesThe 2025 Global Consensus recommends continuing biologics throughout pregnancy in women with inflammatory bowel disease (IBD). Real-world evidence on biologic treatment patterns and outcomes remains limited. This study compared maternal and neonatal outcomes across different biologic use trajectories during pregnancy. MethodsA retrospective study was performed in pregnant women with IBD, treated and/or delivering at the University Hospitals Leuven, Belgium, between 2017 and 2025. Patients were categorized as continuers, discontinuers, non-users or initiators of biologics during pregnancy ResultsAmong 255 pregnancies, 103 (40.4%) were continuers, 68 (26.7%) discontinuers, 77 (30.2%) non-users, and 7 (2.7%) initiators. Before conception, 67.1% used biologics. Third-trimester disease activity was most frequent in initiators (42.9%, 3/7) and discontinuers (19.1%, 13/68), followed by non-users (14.3%, 11/77) and continuers (13.6%, 14/103). C-sections occurred more often in non-users (41.3%, 26/63) and discontinuers (39.4%, 26/66) than continuers (31.1%, 23/74). Preterm birth was more common among initiators (14.3%, 1/7) and discontinuers (12.1%, 8/66) than continuers (8.0%, 6/75) and non-users (3.2%, 2/62). Low birthweight occurred most in initiators (14.3%, 1/7), continuers (8.1%, 6/74) and discontinuers (6.1%, 4/66). Small-for-gestational-age infants were most frequent among continuers (14.9%, 11/74) and initiators (14.3%, 1/7) than discontinuers (7.6%, 5/66). ConclusionsWomen who discontinued biologics during pregnancy had higher rates of C-sections, preterm birth, and third-trimester disease activity than continuers, supporting continuation of biologics in pregnancy. The higher SGA rates among continuers, however, require further investigation. Initiators showed the poorest outcomes, highlighting the need for adequate disease control before and during pregnancy.