To evaluate tumour necrosis factor inhibitor (TNFi) usage patterns in pregnant women with rheumatoid arthritis (RA), ankylosing spondylitis (AS), psoriatic arthritis (PsA), psoriasis (PsO), and inflammatory bowel diseases (IBD), and to compare corticosteroid use in those discontinuing TNFi at specific gestational time points versus those continuing throughout gestation.
We analyzed pregnancies resulting in a live birth among women aged 15-45 with RA, AS, PsA, PsO, and/or IBD, hospitalized for delivery between January 2011 and December 2021, using MarketScan commercial claims database. TNFi exposure was defined as at least one filled prescription or infusion procedure claim for a TNFi. Timing of exposure was categorized by the gestational period and specific trimesters, with a grace period of five half-lives added to each prescription to account for ongoing biological activity.
We identified 3,711 pregnancies exposed to TNFi among 49,925 women with RA, AS, PsA, PsO, and/or IBD. Of the 3,711 pregnancies, 64% had continuous TNFi use throughout all three trimesters. Most (89%) of TNFi-exposed pregnancies had preconception exposure, and 68% continued TNFi postpartum. The proportion of pregnancies with TNFi use throughout all trimesters increased from 55% in 2011-2013 to 73% in 2020-2021 (p-value for trend <0.0001). Corticosteroid use during pregnancy/postpartum was less frequent in pregnancies exposed to TNFi throughout gestation versus those exposed in the first +/- second trimester only.
We observed trends towards increased continuous TNFi use throughout gestation (and fewer corticosteroids in this group), suggesting growing confidence in the safety and effectiveness of TNFi use in pregnancy.