The impact of pregnancy on biologic therapies for the treatment of inflammatory bowel disease.

Active inflammatory bowel disease during conception and pregnancy has been associated with adverse materno-fetal outcomes. Patients are often unduly concerned about the adverse effects of biologic medications on the growing fetus, however, continuing therapy is advised, with potential risks of therapy outweighed by the risks of active maternal disease. A number of physiological changes associated with pregnancy can alter the absorption, distribution and elimination of these therapies, which may impact on their safety and efficacy. We review the current evidence regarding the effects of pregnancy on the pharmacokinetics of biologic therapies, as well as drug concentration measurements during pregnancy and at time of delivery. A greater understanding of the impact of pregnancy on the pharmacokinetics of biologic therapies and the emerging utilisation of drug concentration monitoring during pregnancy may lead to improved materno-fetal outcomes in patients with inflammatory bowel disease.