Neonatal and Pregnancy Outcomes in Pregnant Adults With Pediatric-Onset Crohn's Disease.

Background and Aims: Low birth weight (BW) and preterm birth are recognized complications in women with active Crohn's disease (CD). However, there is limited information on pregnancy and neonatal outcomes in patients diagnosed during childhood and adolescence. This study aims to evaluate the relationship between maternal age at CD diagnosis and pregnancy and neonatal outcomes. Methods: We conducted a retrospective, cross-sectional study of women with CD who delivered between 2012 and 2023. Gestational age (GA) at delivery and (BW) were analyzed as coprimary outcomes. Results: A total of 262 births from 179 mothers were included, with 105 (40.1%) births from women diagnosed with CD before age 18. No significant differences were observed in GA at delivery between groups. There was a significantly higher rate of neonates born small for GA to mothers with adult-onset CD compared with pediatric-onset CD (15.9% vs 3.8%, Conclusion: Neonates born to women with pediatric-onset CD have excellent outcomes including GA and BW percentiles at delivery. Longer disease duration and antitumor necrosis factor therapy were positively associated with improved BW percentiles, while disease activity had a negative impact. These findings suggest that disease control has a more significant impact on neonatal outcomes than age of onset or disease duration.