USE OF INFLIXIMAB IN PREGNANCY

Infliximab is a chimeric human-murine IgG1 monoclonal antibody produced by recombinant DNA technology. It is administered in the treatment of rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, psoriasis, Crohn’s disease and ulcerative colitis where other systemic therapies are ineffective or unsuitable.

The available human pregnancy exposure and outcome data are mainly provided by uncontrolled studies which together describe more than 2,400 infliximab-exposed pregnancies, with more than 1,200 exposed in at least the first trimester. Although the total number of exposed pregnancies is quite large, the available data for specific pregnancy outcomes can be limited and evidence from controlled studies is often lacking.

There is currently no convincing evidence of an association between infliximab and an overall increased risk of congenital malformation, or any specific malformation or pattern of malformations. The available evidence also does not suggest increased risks of miscarriage, intrauterine death, preterm delivery or neurodevelopmental impairment. Although some studies have suggested associations between infliximab exposure and impaired fetal growth, the available data are conflicting and likely confounded by the underlying maternal condition.

Use of immunosuppressant antibodies that actively cross the placenta during pregnancy could result in immunosuppression in the newborn and increase the risk of infection. Rare cases of fatal infection following BCG vaccination after in utero infliximab exposure have been described in the literature. General guidance has been provided from a number of authorities around avoiding/deferring live vaccine use in infants exposed to infliximab in utero. These recommendations vary depending on both the circumstances of infliximab exposure and infant infection risk. UKTIS recommend a case-specific risk assessment approach when considering the use of live vaccines following in utero infliximab exposure. Discussion with UKTIS is recommended in all cases where use of a live vaccine is being considered in an infant <12 months of age where there has been in utero exposure to infliximab.

Pregnant women treated with infliximab are likely to have additional fetal growth monitoring due to their underlying medical condition; no additional fetal monitoring is required as a result of infliximab exposure specifically. Other risk factors may be present in individual cases which may independently increase the risk of adverse pregnancy outcome. Clinicians are reminded of the importance of consideration of such factors when performing case-specific risk assessments.