Pregnancy-Onset Inflammatory Bowel Disease: A Subtle Diagnosis

Background Inflammatory bowel diseases (IBDs) are commonly diagnosed during the reproductive years. IBD first manifested during pregnancy (pregnancy-onset IBD [POIBD]) is still an undescribed entity. The aim of the study was to evaluate the characteristics and maternal and neonatal outcomes of patients with POIBD. Methods Data of all pregnant women with IBD within a single multidisciplinary referral clinic, IBD-MOM, between 2011-2016, were analyzed. Maternal and neonatal characteristics and outcomes were compared between the POIBD group and those diagnosed before pregnancy (non-POIBD). Results We identified 237 women, 31 (15%) from the POIBD group and 206 (85%) from the non-POIBD group. Eight (3.5%) patients experienced early spontaneous pregnancy loss, all in the non-POIBD group. The POIBD diagnosis occurred in 16 (52%) patients during the first trimester, 10 (32%) in second trimester, and 5 (16%) during third trimester. Diagnosis of ulcerative colitis (UC) was significantly more common in the POIBD group compared with the non-POIBD group (22/31, 71% vs 50/206, 24%, respectively, P < 0.001). More UC than Crohn's disease patients had active disease during pregnancy (69% vs 50%, P = 0.03, respectively). POIBD patients experienced vaginal delivery in 100% of births, compared with 164 (79.6%) in the non-POIBD group (P = 0.017). The mean gestational age at birth and the neonatal weight were similar among the study groups; 38.6 weeks and 3040 g for POIBD patients, compared with 38.7 weeks and 3055 g in the non-POIBD group. Conclusions POIBD is a unique clinical entity, and the diagnosis is mostly UC. However, the maternal and neonatal outcomes are similar.