Researchers find no evidence that inflammatory bowel disease (IBD) during pregnancy, or medical treatment for IBD during pregnancy, increases risk for congenital abnormalities in children. The findings, based on a large database analysis, are published in the January issue of Gastroenterology.
IBD frequently affects women of reproductive age, and is often managed with medical therapy. The potential teratogenic effects of drugs are an important concern among women with IBD who are pregnant or considering pregnancy. The safety of a number of drugs commonly used to treat IBD has been assessed in small studies of pregnant women, and researchers have not observed large or consistent increases in numbers of congenital anomalies. However, these studies have not completely convinced many people because they included small numbers of exposures.
Guidelines propose that women should not stop taking drugs that keep their IBD in remission for the purpose of becoming pregnant or protecting a pregnancy. However, many women remain fearful about taking these drugs while pregnant.
Lu Ban et al. conducted a large cohort study of pregnant women with IBD and their children using primary care data from the United Kingdom. They collected data on 386,514 children. Of these, 0.4% were born to mothers who had IBD before childbirth (n=1703); 0.2% were born to mothers with Crohn’s disease (n=893).
Ban et al. identified congenital anomalies in 2.7% of children of mothers with IBD and 2.8% of children of mothers without IBD. No increases in heart, limb, or genital anomalies were found in children of women with IBD.
The authors also found no overall excess risk of a major congenital anomaly in children born to mothers with IBD who were treated with azathioprine/6-mercaptopurine, corticosteroids, or 5-aminosalicylate during pregnancy. Among women with IBD who received medical therapy during pregnancy, the adjusted odds ratios of a major congenital anomaly associated with drug use were 0.82 for 5-aminosalicylates, 0.48 for corticosteroids, and 1.27 for azathioprine/6-mercaptopurine.
Interestingly, 31.2% of women discontinued 5-aminosalicylates and 24.6% discontinued azathioprine/6-mercaptopurine during early stages of pregnancy. The authors did not associate cessation of medication with increased risk of IBD flares later in pregnancy, although this does not mean that no risk exists—the power on this subanalysis was limited.
This is the largest study conducted (in terms of the number of women with IBD, number of births, and number of major congenital anomalies) to assess the risks of congenital anomalies among children of women with IBD.
Ban et al. conclude that neither IBD, nor its common medical treatments, are likely to be major risk factors for congenital anomalies. However, this message may not have reached all pregnant women—up to 31% of women stop taking their medication in pregnancy. Although this could increase the risk of flares later in pregnancy, the authors have not observed such an increase.
Ban et al. remind readers that patients should receive appropriate guidance on use of medication before and during pregnancy.