Drug therapy for inflammatory bowel disease in pregnancy and the puerperium

Inflammatory bowel disease (IBD) has a peak age of onset in the 3rd decade and a peak prevalent age in the fourth decade in most studies. As a result many patients affected by Crohn's disease and ulcerative colitis are females of reproductive age interested in bearing children. It has been shown that the most important factor in the success of a pregnancy in patients with IBD is the state of disease activity. Therefore, the goal prior to and during pregnancy is to best optimise control of the disease through medical therapy. Unfortunately, many medications utilised to treat IBD are potentially toxic and/or teratogenic, leaving many physicians and patients without a clear answer as to the safest methods of therapy. This review attempts to summarise the medical literature to date, as it pertains to the safety of medical therapy for IBD during pregnancy and the puerperium.

Introduction

Inflammatory bowel disease (IBD) is a chronic inflammatory condition with peak onset during young adulthood (between the ages of 15 and 25 years). There is evidence that Crohn's disease has been increasing in incidence over the last 30 years and at an even higher rate in women.¹ Also, IBD has become a much better managed condition over the last two decades as more effective therapies have become available. These three observations contribute to the rising number of young women of childbearing age with IBD, interested in conceiving and maintaining pregnancies. Despite this, many questions still surround the management IBD during pregnancies.

Although various studies have shown that a diagnosis of either ulcerative colitis (UC) or Crohn's Disease (CD) does not by itself pose a risk to pregnancy,2, 3 it has been shown that active disease or disease flare, is associated with poor obstetrical outcomes.3, 4 As a result, effective control of disease activity is vitally important during pregnancy. Unfortunately, there are no specific guidelines outlining exactly how a physician should most safely and effectively treat IBD during pregnancy. This is most likely due to the fact that direct prospective studies examining the effects of medications on live pregnancies are rare. Also, assigning blame to any one medication for causing a particularly bad outcome (i.e. malformation, low birth weight, or foetal loss) would ideally be proven in controlled trials and in the absence of such studies should occur consistently at a particular stage of pregnancy and with a consistent type of adverse event. In the IBD population in particular, this is difficult because patients often receive multiple medications to control the disease process and symptoms related to the disease. As well, it is often impossible to extract the effect of a medication from the effect of a multi-system disease, with highly variable presentations such as IBD.

The following review analyses the available literature to date as it pertains to the safety of the most commonly used medications for the treatment of IBD during pregnancy and lactation. Where possible the latest information from meta-analyses and larger case control trials are used to support our therapeutic suggestions. As well, we have included relevant information regarding the Food and Drug Administration (FDA) classifications and recommendations for each drug we discuss. These recommendations can be quickly referenced in Table 1, Table 2.