Inflammatory bowel disease (IBD) refers to two diseases: ulcerative colitis and Crohn’s disease. Both are chronic diseases causing inflammation of the bowel. Although they vary in peak incidence, Crohn’s disease and ulcerative colitis commonly affect women of reproductive age. Studies have shown that women with poorly controlled IBD are more likely to deliver premature and low birth weight infants as compared with their healthy counterparts. They also have a higher rate of cesarean sections. Congenital anomalies, although data is not clear, seem to be higher in infants of mothers with IBD.
There are several drugs that are used in the treatment of IBD. Although some are considerd safe to use in pregnancy, others have limited data which can pose a problem with disease management in pregnancy. (1)
5-Aminosalicylic acid (5-ASA)- This drug has been found to have limited transplacental transfer as well as systemic absorption. Studies have not found an increase in congenital malformations following the use of this drug.
Sulfasalazine- Sulfasalazine crosses the placenta; it has been determined to be safe to use in pregnancy. Sulfasalazine is a folic acid antagonist; therefore, supplementation with folic acid is essential.
Corticosteroids- steroids have been shown to increase the risk of preterm labor and in some studies have been linked with an increase in the number of oral clefts.
Azathioprine and 6-mercaptopurine - Azathioprine and 6-mercaptopurine are both immunosuppressants that have been associated with an increase risk of preterm birth and congenital anomalies when used in pregnant patients.
Infliximab- Infliximab is an antibody preparation commonly used in various autoimmune disorders. We have only limited data on its use in pregnancy, see below.
Description (Pregnancy outcomes in women with inflammatory bowel disease).
In a meta-analysis published in 2007, the authors studied the pregnancy outcomes of women diagnosed with inflammatory bowel disease. A total of 3,907 patients with some sort of inflammatory bowel disease (either Crohn’s disease or ulcerative colitis) were compared with 320,531 controls. The study found that women with IBD were more likely to have low-birth weight infants, premature infants, and infants born via cesarean section. The study also found a two fold increase in the number of infants born with congenital malformations. (2)
A case control study, conducted by the Department of Obstetrics, Gynecology, and Reproductive Sciences at Mount Sinai Medical Center in New York, studied 116 pregnant women with IBD who gave birth to singleton babies and compared these to 56,398 controls. This study reviewed pregnancies between the years 1986 and 2001. This study did not find an association between inflammatory bowel disease, without IBD surgery, and an unfavorable pregnancy result. (3)
References:
1. Brar H, Einarson A. Effects and treatment of inflammatory bowel disease during pregnancy. Can Fam Physician. Jul 2008;54(7):981-983.
2. Cornish J, Tan E, Teare J, et al. A meta-analysis on the influence of inflammatory bowel disease on pregnancy. Gut. Jun 2007;56(6):830-837.
3. Bush MC, Patel S, Lapinski RH, Stone JL. Perinatal outcomes in inflammatory bowel disease. J Matern Fetal Neonatal Med. Apr 2004;15(4):237-241.
