American Journal of Gastroenterology ISSN 0002-9270 C  2006 by Am. Coll. of Gastroenterology doi: 10.1111/j.1572-0241.2006.00602.x Published by Blackwell Publishing Does Pregnancy Change the Disease Course? A Study in a European Cohort of Patients with Inflammatory Bowel Disease Lene Riis, 1 Ida Vind, 2 Patrizia Politi, 3 Frank Wolters, 4 Severine Vermeire, 5 Epameinondas Tsianos, 6 Jo˜ ao Freitas, 7 Ioannis Mouzas, 8 Victor Ruiz Ochoa, 9 Colm O’Morain, 10 Selwyn Odes, 11 Vibeke Binder, 1 Bjørn Moum, 12 Reinhold Stockbr ¨ ugger, 4 Ebbe Langholz, 13 and Pia Munkholm, 1 on behalf of the European Collaborative study group on Inflammatory Bowel Disease (EC-IBD) 1 Department of Medical Gastroenterology, Herlev Hospital, University of Copenhagen, Herlev Denmark; 2 Department of Gastroenterology, Hvidovre Hospital, University of Copenhagen, Hvidovre, Denmark; 3 Servicio di Gastroenterologia, Ospedale di Cremona, Cremona, Italy; 4 Department of Gastroenterology and Hepatology, University Hospital Maastricht, Maastricht, The Netherlands; 5 Department of Gastroenterology, UZ Gasthuisberg, Leuven, Belgium; 6 Division of Internal Medicine, University of Ioannina, Ioannina, Greece; 7 Department of Gastroenterology, Almada Regional Health Department, Almada, Portugal; 8 Department of Gastroenterology, University General Hospital, Heraklion, Crete, Greece; 9 Gastroenterology Unit, Complexo Hospitalario, Universitario de Vigo, Vigo, Spain; 10 Department of Gastroenterology, Adelaide and Meath Hospital, Trinity College, Tallaght, Dublin, Ireland; 11 Gastroenterology Unit, Soroka University Hospital and Ben Gurion University, Beer Sheva, Israel; 12 Department of Medicine, Section for Gastroenterology, Ostfold Central Hospital, Fredrikstad, Norway; and 13 Department of Internal Medicine, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark BACKGROUND Inflammatory bowel disease (IBD) often affects patients in their fertile age. The aim of this study AND AIMS: was to describe pregnancy outcome in a European cohort of IBD patients. As data are limited regarding the effect of pregnancy on disease course, our second objective was to investigate whether pregnancy influences disease course and phenotype in IBD patients. METHODS: In a European cohort of IBD patients, a 10-yr follow-up was performed by scrutinizing patient files and approaching the patients with a questionnaire. The cohort comprised 1,125 patients, of whom 543 were women. Data from 173 female ulcerative colitis (UC) and 93 Crohn’s disease (CD) patients form the basis for the present study. RESULTS: In all, 580 pregnancies, 403 occurring before and 177 after IBD was diagnosed, were reported. The rate of spontaneous abortion increased after IBD was diagnosed (6.5% vs. 13%, p = 0.005), whereas elective abortion was not significantly different. 48.6% of the patients took medication at the time of conception and 46.9% during pregnancy. The use of cesarean section increased after IBD diagnosis (8.1% vs 28.7% of pregnancies). CD patients pregnant during the disease course, did not differ from patients who were not pregnant during the disease course regarding the development of stenosis (37% vs 52% p = 0.13) and resection rates (mean number of resections 0.52 vs 0.66, p = 0.37). The rate of relapse decreased in the years following pregnancy in both UC (0.34 vs 0.18 flares/yr, p = 0.008) and CD patients (0.76 vs 0.12 flares/yr, p = 0.004). CONCLUSIONS: Pregnancy did not influence disease phenotype or surgery rates, but was associated with a reduced number of flares in the following years. (Am J Gastroenterol 2006;101:1539–1545) INTRODUCTION Crohn’s disease (CD) and ulcerative colitis (UC) often affect patients in their fertile age. It has been estimated that around 25% of female patients conceive after the diagnosis of inflam- matory bowel disease (IBD). Many studies have been con- cerned with the impact of IBD on fertility and pregnancy and especially pregnancy outcome. Fertility seems to be slightly decreased in CD patients with active disease (1–3) and in UC patients after pouch surgery (4–8)—otherwise fertility in female IBD patients is reported to be comparable to the 1539