Which RA agents are absolutely contraindicated in pregnancy?

Methotrexate and leflunomide are classified as absolutely contraindicated in pregnancy due to their significant teratogenic effects. Methotrexate is a folate antagonist that can interfere with embryonic development, leading to severe birth defects if exposure occurs during pregnancy. This medication is known to cause cognitive impairment, craniofacial abnormalities, and various other congenital malformations.

Similarly, leflunomide has a long half-life and has also been linked to teratogenic effects, including limb reduction defects and other serious fetal outcomes. Both medications can cause severe harm to the developing fetus, making them unsafe for use in pregnant individuals.

In contrast, while other disease-modifying antirheumatic drugs (DMARDs) such as abatacept, rituximab, adalimumab, certolizumab, infliximab, and etanercept may have considerations regarding their use during pregnancy, they do not carry the same absolute contraindications as methotrexate and leflunomide. Some of these agents are classified under specific categories regarding pregnancy safety and may be used if the benefits outweigh the risks. Hence, the correct answer identifies the agents that are unequivocally unsafe in the context of