Absence of infliximab in infants and breast milk from nursing mothers receiving therapy for Crohn's disease before and after delivery.

Goals: The objective of this study was to determine whether infliximab, an antitumor necrosis factor monoclonal antibody, is transferred in utero or through breast milk from nursing Crohn's disease patients to their newborns.

Background: Crohn's disease most often occurs in women of childbearing age. Many of these women receive treatment for their disease, but are advised to terminate therapy while pregnant or nursing.

Study: Three patients diagnosed with Crohn's disease who had a history of infliximab use during and after pregnancy were followed prospectively. Patients received 5-mg/kg infliximab at regular intervals until approximately gestational week 30, and resumed infliximab treatment within 3 to 14 days after giving birth. Serum samples from patients and children and breast milk samples were collected postpartum. The concentration of infliximab in the serum and milk samples was measured using an enzyme-linked immmunosorbent assay.

Results: The levels of infliximab detected in the mothers' serum samples postpartum were 74.27, 62.62, and 59.97 microg/mL, respectively. However, infliximab was undetectable (<0.10 microg/mL) in the sera of the newborn children. Likewise, infliximab was undetectable in the breast milk of the nursing mothers.

Conclusions: Infliximab was detected in the mothers' sera, but not in the breast milk of nursing mothers or in the sera of the breast-fed newborns. Data from this small series of patients suggest that infliximab was not transferred from mother to child, either in utero or through breast milk. These data suggest that mothers receiving infliximab should not be discouraged from nursing their children.