Pregnancy in women with inflammatory bowel disease: a French nationwide study 2010‐2018

Summary Background Inflammatory bowel disease (IBD) most commonly occurs in young adults, including women of child‐bearing age. Aim To describe pregnancy in women with IBD in the age of widespread use of biologics Methods Using French national health data system (SNDS) data, we identified all pregnancies ending between 1 April 2010 and 31 December 2018 in patients with and without IBD in France. Pregnancy and IBD characteristics were described. Pregnancy outcomes were compared between IBD and non‐IBD pregnancies using multivariable logistic regression models. Results We included 36 654 IBD and 8 595 562 non‐IBD pregnancies. Among IBD pregnancies, 75.6% ended in live births and 0.4% in stillbirths. Pregnancies in women with IBD vs those without IBD more frequently resulted in preterm birth (8.0% vs 5.5%, aOR 1.51; 95% CI: 1.45‐1.58), small for gestational age birth (11.1% vs 9.8%, aOR 1.15; 95% CI: 1.10‐1.20) and caesarean section (26.1% vs 20.0%, aOR 1.39; 95% CI: 1.35‐1.42). Active IBD before and during pregnancy was associated with particularly marked increases in the rates of prematurity and small for gestational age as compared to non‐IBD pregnancies. Active IBD during pregnancy was associated with more stillbirths than non‐IBD pregnancies (aOR 1.43 95% CI: 1.09‐1.86). Crohn's disease activity decreased during pregnancy, while ulcerative colitis activity did not change. Conclusions Pregnancies in women with IBD are associated with increased risks of prematurity, small for gestational age and caesarean section, especially among women with active IBD. Disease activity decreased during pregnancy in women with Crohn's disease, but was unchanged in women with ulcerative colitis.