Is it Safe to Take a Biologic During Pregnancy?

Biologics are becoming more commonly used to treat autoimmune diseases, but because these therapies are relatively new, there have been fewer studies on how they affect pregnancy and birth outcomes. While some drugs like methotrexate are known to adversely affect pregnancy, uncontrolled autoimmune disease is a risk factor for adverse pregnancy outcomes. The key is to choose a medication that best controls disease that has minimal negative impacts on pregnancy.

A recent study combed through 40 studies involving 11,712 autoimmune rheumatic disease patients to analyze any potential adverse pregnancy outcomes – such as pre-term birth, low birth weight, preeclampsia, and miscarriages — associated with biologic exposure. 

Overall, the study did not find that biologics led to a higher prevalence of adverse pregnancy outcomes in people with autoimmune rheumatic disease. 

The study emphasizes that TNF inhibitors are associated with reduced prevalence of some adverse pregnancy outcomes, while other biologics may have a higher risk. Data also shows that while biologics can cross the placenta, they have a limited impact on embryonic or fetal development.

Future studies such as this one can help inform biologic choice during pregnancy to maximize the health of the pregnancy and offspring while keeping symptoms of autoimmune disease under control.

Citation

Li, S., et al. (2025). Safety of biologics in patients with autoimmune rheumatic diseases during pregnancy: Systematic review and meta-analysis. Autoimmunity Reviews, 24(8):103827. https://doi.org/10.1016/j.autrev.2025.103827