The safety of drugs for inflammatory bowel disease during pregnancy and breastfeeding: the DUMBO registry study protocol of GETECCU

Background: Active disease during conception and pregnancy in women with inflammatory bowel disease (IBD) increases the risk of pregnancy complications and adverse neonatal outcomes. The use of IBD treatments during pregnancy should be weighed against their adverse effects on the neonate, but longer-term safety data and data on serious infection rates and malignancies postnatally are lacking, particularly for newer drugs, such as tofacitinib, vedolizumab and ustekinumab. Methods: This ongoing, prospective registry study being conducted at 70 centres in Spain is enrolling pregnant women who are ⩾18 years, are at any point in pregnancy up to the end of the second trimester and have a diagnosis of Crohn’s disease, ulcerative colitis or unclassified IBD. Patients will receive treatment decided independently by their IBD specialist. Each incident gestation will be followed up through pregnancy and the first 4 years postnatally. Three cohorts will be compared: biologicals exposed, immunomodulatory exposed and non-exposed. The primary endpoint is the risk of severe infection in newborns postnatally up to 4 years of age; other endpoints include serious adverse events (SAEs) such as pregnancy and delivery complications, neonatal SAEs, development [Ages and Stages Questionnaire-3 (ASQ3)], and malignancy incidence, up to 4 years of age. IBD specialists will collect maternal data (baseline/end of each trimester/1 month post-delivery), neonatal birth data, and the SAE and ASQ3 data in children exposed during pregnancy, reported every 3 months by the mother. Statistical analysis will include summary statistics for quantitative variables, comparisons of qualitative variables with significance set at p