Biologic therapies and pregnancy: the story so far

Biologic therapies have revolutionized treatment outcomes for patients with inflammatory arthritis. However, there remains a concern regarding their safety during conception, pregnancy and breastfeeding. Data on the safety of these treatments are largely limited to uncontrolled case reports. Collective evidence from many hundreds of pregnancies in inflammatory arthritis and IBD have suggested that exposure to anti-TNF therapies at the time of conception or during the first trimester does not result in an increased risk of adverse pregnancy and fetal outcomes. Monoclonal antibodies, and to a lesser extent recombinant fusion proteins, do cross the placenta during the second and third trimester and are functional in the fetus, as evidence by lymphopaenia reported at birth in children exposed to rituximab in utero. In addition, live vaccines should be avoided in children with in utero exposure to biologics for at least the first 6 months of life. The longer-term effects of in utero exposure remain unknown. Studies suggest that many of these drugs do enter breast milk in small amounts, but the extent to which they are absorbed by the infant is less clear. Limited reports have not suggested adverse pregnancy outcomes in women whose partners were exposed to anti-TNF therapies or rituximab at the time of conception. Data on other biologic therapies, including anakinra, abatacept and tocilizumab, in both men and women remain extremely limited.