Drug transfer to the fetus and to the breastfeeding infant: what do we know?

The pregnant patient with inflammatory bowel disease presents a number of challenges to the clinician. In addition to the management of the patient's disease activity and the potential effects of disease on pregnancy, the clinician must also take into consideration any iatrogenic complications that may arise from the medical management of these conditions. Furthermore, should the patient elect to breastfeed her infant, the effect of drugs that may be passed through the breast milk must also be considered. This article focuses specifically on the issues of drug transfer to the fetus and to the breastfeeding infant. Meperidine is the sedative of choice for endoscopic procedures on pregnant patients, while benzodiazepines and propofol may be used with certain caveats. Amoxicillin/clavulanic acid and metronidazole are preferred if antibiotics are indicated for perianal Crohn's disease or pouchitis. The majority of medications used in the treatment of luminal IBD in pregnancy are not associated with significant adverse effects, and thus can generally be used safely. Certain medications, such as aminosalicylates, corticosteroids, and cyclosporine, appear low risk, while others such as methotrexate and thalidomide are clearly contraindicated. The role of other immunomodulators and biologics remains to be clearly defined, although early experience with infliximab and similar agents appear to be low risk. Safety in breastfeeding varies considerably among medications. There are many issues to address when considering pharmaceutical intervention in the pregnant patient, and patients should be carefully counseled regarding potential teratogenicity or adverse outcomes of medication used during pregnancy and breastfeeding.