Inflammatory Bowel Disease Increases Risk of Adverse Pregnancy Outcomes: A Meta-Analysis

Aoibhlinn O’Toole, Ogochukwu Nwanne, Tracy Tomlinson

Inflammatory bowel disease may place women at greater risk of adverse pregnancy outcomes. To examine the association between inflammatory bowel disease and adverse pregnancy outcomes: preterm birth, small for gestational age (SGA) birth weight, congenital anomalies, and stillbirth. We searched PubMed, EMBASE, the Cochrane Database of Systematic Reviews, and ClinicalTrials.gov for studies published from January 1980 through February 2014 and reference lists of relevant studies. We reviewed 1748 citations and identified studies evaluating outcomes of pregnancies complicated by inflammatory bowel disease. Selected studies evaluated one or more of the outcomes of interest, were in English, and gave sufficient details to perform meta-analysis. Three investigators independently reviewed articles for inclusion; discordant decisions were resolved by team review and consensus. Twenty-three studies that included 15,007 women with inflammatory bowel disease (5449 Crohn's, 6559 ulcerative colitis) and 4,614,271 controls met selection criteria. Random-effects analytical methods were used to generate pooled odds ratios. We found an increased odds of the outcomes studied among women with inflammatory bowel disease compared with non-diseased controls: 1.85 for preterm birth (22 studies; 95 % confidence interval [CI] 1.67-2.05), 1.36 for SGA birth weight (13 studies; 95 % CI 1.16-1.60), 1.57 for stillbirth (10 studies; 95 % CI 1.03-2.38), and 1.29 for congenital anomalies (11 studies; 95 % CI 1.05-1.58). The latter result, however, may be unreliable secondary to publication bias. Inflammatory bowel disease may increase the odds of adverse pregnancy outcomes.