Chronic inflammatory conditions, including inflammatory bowel diseases (IBD), psoriasis, and psoriatic arthritis, are prevalent among women of reproductive age; patients with active disease during pregnancy may be at an increased risk of adverse birth outcomes. For this reason, physicians are focused on approaches to controlling disease activity prior to and during pregnancy. The safety profile of many therapies used for these conditions has been relatively well established, though evidence on newer therapies is lacking. Ustekinumab is a relatively new interleukin-12/23 inhibitor approved for IBD, psoriasis, and psoriatic arthritis, whose safety in pregnancy is not yet fully understood. In this comprehensive review, we critically assess the available evidence on ustekinumab in pregnancy across animal studies and human case reports, case series, observational studies, and clinical practice guidelines. We show that, to date, studies have not identified an excess risk of adverse pregnancy outcomes among women exposed to ustekinumab in pregnancy, with few exposed pregnancies and potential for some bias. Clinical guidelines are conflicted regarding whether they recommend continuing or discontinuing ustekinumab, highlighting the paucity of data and need for more research on this issue.
© 2021 American College of Rheumatology.