Anti-rheumatic Drugs in Pregnancy and Lactation

Autoimmune rheumatic diseases (AIRDs) frequently affect individuals of reproductive age, necessitating careful management during conception, pregnancy, and lactation. Active disease is strongly associated with adverse pregnancy outcomes; therefore, ensuring achieving remission or low disease activity through pregnancy-compatible therapies is paramount. Physiological changes in pregnancy alter pharmacokinetics but rarely require major dose adjustments. Conventional synthetic disease-modifying anti-rheumatic drugs (DMARDs) such as hydroxychloroquine, sulfasalazine, and azathioprine, alongside selected biologics—particularly TNF inhibitors—are considered safe and widely recommended by international guidelines. In contrast, methotrexate, leflunomide, mycophenolate mofetil, and cyclophosphamide remain contraindicated except in life-threatening maternal disease. Emerging evidence supports treat-to-target strategies and continued use of TNFi throughout pregnancy to prevent flares, with tailored infant vaccination schedules when exposure occurs late in gestation. Breastfeeding is compatible with most csDMARDs, TNFi, and several biologics, whilst drugs with high oral bioavailability or toxicity, such as cyclophosphamide, should be avoided. Persistent evidence gaps—especially regarding non-TNFi biologics, targeted synthetic DMARDs, and long-term child outcomes—highlight the need for inclusive clinical trials and robust registries to optimise reproductive care in AIRDs.