Abstract Background IBD remission is key for pregnancy outcomes. Previous studies have suggested an IBD relapse risk of approximately 30% in patients in remission at conception, but this could be influenced by disease control in the periconceptional period and the discontinuation of treatments for IBD during pregnancy. Aim To provide updated data on the incidence of disease relapse during pregnancy in IBD patients and to identify predictive factors of relapse. Methods Pregnant patients with IBD from DUMBO registry were included. DUMBO is a prospective, observational, and multicentre registry, endorsed by GETECCU, which enrols pregnant women with IBD over 5 years in 70 centres in Spain. Study protocol is summarized in figure 1a. Relapse was defined based on the Crohn’s Disease Activity Index and the Partial Mayo Score in Crohn’s disease (CD) and ulcerative colitis (UC), respectively. Only patients in clinical remission at conception were considered for the relapse risk analysis (by Cox-regression). Results Overall, 993 patients were available in DUMBO registry, 38 (4%) with active disease at conception. 961 patients gave birth (97% singleton), 0.4% had an abortion, 2.3% had miscarriages and 0.3% had a stillbirth. The probability of having active disease at each trimester was higher in patients with active disease at conception (table 1a). Seven patients underwent surgery due to IBD during pregnancy (4 abdominal and 3 perianal surgery); all of them were in remission at conception. A total of 112 out of 868 (12.9%) patients in remission at conception relapsed throughout pregnancy or puerperium (table 1b). The proportion of patients who discontinued treatment during pregnancy, with the exception of mesalamine, was similar between relapsers and non-relapsers (table 1c). Having UC (vs. CD) (Hazard ratio = 3.48, 95% confidence interval = 2.36–5.30) and higher C-reactive protein levels at conception (mg/dL) (Hazard ratio = 1.11, 95% confidence interval = 1.04–1.19) were the only variables associated with the risk of relapse. Conclusion Patients with active disease at conception had a higher risk of remaining active during pregnancy, whereas those who conceived in remission showed a lower risk of relapse than previously reported. Relapse was three times more frequent in UC than in CD. As serious complications, including the need for surgeries, may arise even in patients who enter pregnancy in remission, close monitoring of IBD throughout pregnancy is warranted. Conflict of interest: Tomás, Susana: No conflict of interest Leo Carnerero, Eduardo: No conflict of interest Calviño Suárez, Cristina: No conflict of interest Martin Arranz, Maria Dolores: No conflict of interest Zabalza San Martín, Lucía: No conflict of interest Perez Martinez, Isabel: No conflict of interest Calvo Moya, Marta Isabel: I have participated in presentations / advisory boards / research supported by: AbbVie, Takeda, Johnson & Johnson, Pfizer, Lilly, MSD, Chiesi, Dr Falk Pharma, Shire Pharmaceuticals, FAES, FERRING, Tillotts Pharma, Galapagos and Alfasigma Fernandez Clotet, Agnes: No conflict of interest Arroyo Villarino, Maria Teresa: No conflict of interest Diz Lois Palomares, Maria Teresa: No conflict of interest Marin Pedrosa, Sandra: No conflict of interest Hernández Ramirez, Vicente: No conflict of interest Rivero Tirado, Montserrat: No conflict of interest Casanova, María José: No conflict of interest Ruiz-Cerulla, Alexandra: No conflict of interest Corsino, Pilar: No conflict of interest Huguet, José María: No conflict of interest Guerra Marina, Ivan: No conflict of interest Valldosera, Gemma: No conflict of interest Hervias Cruz, Daniel: No conflict of interest Rodríguez-Lago, Iago: No conflict of interest Arias Garcia, Maria Lara: No conflict of interest Bejarano Garcia, Ana: No conflict of interest Gutiérrez Casbas, Ana: No conflict of interest Camargo Camero, Raquel: No conflict of interest Gonzalez Lama, Yago: No conflict of interest Lopez Serrano, Maria Pilar: No conflict of interest Ceballos Santos, Daniel: No conflict of interest Vega Villaamil, Pablo: No conflict of interest De Jorge Turrión, Miguel Ángel: No conflict of interest Lucendo, Alfredo: No conflict of interest Manuel, Van Domselaar: No conflict of interest Echarri Piudo, Ana: No conflict of interest Bujanda, Luis: No conflict of interest Aguas, Peris: No conflict of interest Tardillo Marin, Carlos Alberto: No conflict of interest Zúñiga de Mora-Figueroa, Beatriz: No conflict of interest Piqueras Cano, Marta: none Gisbert, Javier: No conflict of interest Chaparro, María: No conflict of interest
Tomás et al. (Thu,) studied this question.