TOPLINE:
TNF inhibitors were used by 64% of pregnant women with inflammatory diseases through all trimesters. Those with continuous use through all trimesters had reduced use of corticosteroids postpartum.
METHODOLOGY:
- Researchers analyzed prescriptions of TNF inhibitors in pregnant women with chronic inflammatory diseases in the MarketScan US commercial claims database, focusing on usage patterns and discontinuation compared with those who continued using them throughout pregnancy.
- They included live birth pregnancies among women aged 15-45 years with rheumatoid arthritis, radiographic axial spondyloarthritis, psoriatic arthritis, psoriasis, and/or inflammatory bowel disease who were hospitalized between 2011 and 2021.
- A total of 3711 pregnancies were exposed to TNF inhibitors during gestation, with use of TNF inhibitors defined as having at least one filled prescription or infusion during the preconception, gestation, or postpartum periods.
- The time of exposure during pregnancy was categorized by trimesters, with a grace period of five half-lives added to account for biologic activity.
- TNF inhibitors were classified by high or low placental transfer ability, using national drug and procedure codes. The use of systemic corticosteroids and nonbiologic disease-modifying antirheumatic drugs was also assessed.
TAKEAWAY:
- Overall, 64% of pregnancies were exposed to TNF inhibitors throughout all trimesters, whereas 17% were exposed during a single trimester and 18% during two trimesters. Additionally, 89% had preconception exposure, and 68% had postpartum exposure.
- Among pregnant women with inflammatory bowel disease, 84% continued using TNF inhibitors throughout all trimesters. A higher proportion of pregnant women with rheumatoid arthritis, psoriatic arthritis, and radiographic axial spondyloarthritis/psoriasis discontinued TNF inhibitors before the third trimester than those with inflammatory bowel disease.
- The proportion of pregnancies exposed to TNF inhibitors throughout all trimesters increased from 55% in 2011-2013 to 73% in 2020-2021 (P for trend < .001). Pregnancies with continuous use of TNF inhibitors had lower use of corticosteroids during pregnancy and postpartum than those with limited exposure.
- Exposure to TNF inhibitors with a high placental transfer ability was seen in 73% of pregnancies, whereas exposure to low-transfer agents was seen in 27%; switching from high- to low-transfer TNF inhibitors occurred in 1.4% of pregnancies, with 0.2% switching from low- to high-transfer agents.
IN PRACTICE:
“Our findings suggest a trend toward increased TNFi [inhibitor] continuation throughout gestation. As TNFi continue to be widely used, ongoing evaluation of their safety and long-term outcomes during pregnancy will be critical, notably related to immunization response in offspring. This information will inform future guidelines and help optimize the health of mothers with chronic inflammatory disease and their children,” the authors of the study concluded.
SOURCE:
This study was led by Leah K. Flatman, PhD, McGill University, Montreal, Quebec, Canada. It was published online on June 15, 2025, in The Journal of Rheumatology.
LIMITATIONS:
The study’s retrospective design may lead to residual confounding because it relied on administrative data. The lack of detailed clinical information, such as disease activity levels and reasons for stopping TNF inhibitors, limited the understanding of treatment decisions. Potential misclassification of TNF inhibitor exposure and gestational timing exists owing to reliance on claims data. The exclusion of stillbirths limits the generalizability of findings, and the focus on commercially insured women may not reflect broader populations.
DISCLOSURES:
This study was funded by the Canadian Institutes of Health Research (CIHR) project grant and the Arthritis Society Stars Career Development Award to an author who also reported receiving senior salary support from the Fonds de Recherche du Québec — Santé. Another author received support from a CIHR Canada Graduate Scholarships Doctoral Award. No relevant conflicts of interest were disclosed by the authors.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.