Pregnancy Outcomes in Women With Inflammatory Bowel Disease: A Large Community-Based Study From Northern California

Background & Aims: The aim of this study was to determine whether pregnancy outcomes differ between women with and without inflammatory bowel disease (IBD) and to determine what risk factors adversely affect outcomes. Methods: We conducted a cohort study of all pregnant women within the Northern California Kaiser Permanente membership between the years 1995 and 2002. We abstracted the records of all pregnancies in women with IBD (exposed cohort) and a random sample of pregnancies from age-matched women without IBD (unexposed cohort) and evaluated risk factors for spontaneous abortion, complications of pregnancy, and adverse newborn events. Results: A total of 461 pregnant women with IBD were matched to 493 unexposed pregnant women. Women with IBD were more likely to have an adverse conception outcome (odds ratio, 1.65; 95% confidence interval, 1.09–2.48), an adverse pregnancy outcome (odds ratio, 1.54; 95% confidence interval, 1.00–2.38), or a pregnancy complication (odds ratio, 1.78; 95% confidence interval, 1.13–2.81); however, the difference between the 2 groups in adverse newborn outcomes was not statistically significant (odds ratio, 1.89; 95% confidence interval, 0.98–3.69). Independent predictors of an adverse outcome included a diagnosis of IBD, a history of surgery for IBD, and non-Caucasian ethnicity. Severity of disease and medical treatments were not associated with an adverse outcome. Conclusions: Women with IBD are more likely to have an adverse outcome related to pregnancy. Disease activity and medical treatment did not predict adverse outcomes in a large, nonreferral population.