Delivery and Disease Outcomes of Pregnant Adults With Pediatric-Onset Crohn’s Disease

Background: There are limited studies assessing the impact of pediatric-onset inflammatory bowel disease (IBD) on infant and pregnancy outcomes. Low birth weight and preterm birth are known pregnancy complications in IBD patients with active disease. Therefore, this study sought to evaluate pregnancy outcomes in patients with pediatric-onset versus adult-onset Crohn’s disease (CD), particularly with regard to intrauterine growth and prematurity delivery. Methods: In this single center, retrospective comparative cohort study, patients with pediatric-onset (diagnosed < 18 years old) and adult-onset CD (diagnosed ≥18 years old) who had documented prenatal care between 2012-2023 were identified. Patients were excluded for following at outside institutions for primary IBD care. We compared co-primary outcomes (gestational age and size), and secondary outcomes (assisted reproduction usage, mode of delivery, and neonatal intensive care unit (NICU) stay), between the two groups. Data was obtained from an electronic medical record via natural language processing and confirmed with manual verification. Categorical variables were analyzed using chi-squared test or Fisher exact test when appropriate; continuous variables were assessed with t-test if normally distributed. Statistical significance was determined by p value < 0.05. Results: A total of 208 infants were delivered, 119 to pediatric-onset CD and eighty-nine to adult-onset CD mothers. There was no significant difference with regard to race between the groups. The mother’s age at delivery was significantly lower in pediatric-onset CD patients (median [IQR]: 30.2 [26.3, 34.5] vs 32.5 [29.8, 35.3] years, p=0.0006). There was a numerically increased rate of perianal disease in pediatric-onset CD patients (26.8% vs. 15.7%, p=0.055). No statistical difference was seen in gestational age between the two groups (median [IQR]: pediatric-onset: 39.1 [38.6, 39.6]; adult-onset: 39.1 [38, 39.6], p=0.7). There was a statistically significant increase in small for gestational age infants born to adult-onset CD (15.73% vs 5.04%, p=0.001) compared to pediatric-onset CD. Higher rates of Cesarian delivery (57.9% vs. 39.3%, p=0.006) were noted in pediatric-onset CD. NICU admission rates, septic abortion, and intrauterine demise were similar between the two groups. There was increased use of biologics at conception (47.9% vs. 34.8%, p=0.0011) in pediatric-onset CD while there were increased rates of intrapartum (7.6% vs. 20.2%, p=0.007) and post-partum disease flares (10.9% vs 21.3%, p=0.039) in adult-onset CD. Conclusions: This study identifies safer outcomes during and after pregnancy in pediatric-onset compared to adult-onset CD. We found significantly higher rates of biologic use with reduced rates of intra- and post-partum disease flares in mothers with pediatric-onset CD. We also found excellent birth outcomes with regard to gestational age and size at delivery in all patients with CD. Future studies assessing these comparisons regarding biologic use and disease activity should be completed to further understand the effect of pediatric-onset CD on pregnancy outcomes.