Outcomes of infants born to mothers with inflammatory bowel disease: a population-based cohort study.

OBJECTIVE: Limited population-based data on inflammatory bowel disease (IBD) and pregnancy outcomes exist. The purpose of this study is to determine the association between maternal IBD status and adverse pregnancy outcomes.

METHODS: Using computerized birth records of infants born to mothers with Crohn's disease (CD) or ulcerative colitis (UC) and mothers without diagnoses of IBD (no-IBD) in Washington State, we performed a cross-sectional retrospective study to determine gestational age, birth weight, and congenital malformations.

RESULTS: Preterm delivery was seen in 15.2% of CD births, 10.4% of UC births, and 7.2% of no-IBD births. Low birth weight was found in 16.8% of CD births, 7.6% of UC births, and 5.3% of no-IBD births. Smallness for gestational age was present in 15.2% of CD births, 10.5% of UC births, and 6.9% of no-IBD births. Only CD births were at significantly increased risk of preterm delivery (p < 0.0025), low birth weight (p < 0.001), and smallness for gestational age (p < 0.001). Congenital malformations were more commonly recorded in UC births than in controls (7.9% vs 1.7%, p < 0.001), whereas 3.4% of CD births had malformations recorded. Using multivariable logistic regression, CD births were more likely to be preterm (odds ratio [OR] = 2.3, 95% CI = 1.4-3.8) and have low birth weights (OR = 3.6, CI = 2.2-5.9) and smallness for gestational age (OR = 2.3, CI = 1.3-3.9). UC births were more likely to have congenital malformations reported (OR = 3.8, CI = 1.5-9.8).

CONCLUSIONS: Maternal IBD is associated with increased odds of preterm delivery, low birth weight, smallness for gestational age (CD), and reporting of congenital malformations (UC).