Clinical and demographic features of patients with rheumatoid arthritis included in the PreCARA cohort (n=184) and PARA cohort (n=253) that were used for the current data analysis
| Variable | PreCARA cohort | PARA cohort | P value |
| Mean age at delivery, years (SD) | 32.8 (3.9) | 32.7 (3.8) | 0.88 |
| Median disease duration at first visit, years (IQR) | 6.8 (3.7–10.7) | 4.9 (2.2–9.7) | 0.009 |
| Erosive disease, n (%) | 52 (28.3) | 161 (63.7) | <0.001 |
| Rheumatoid factor positive and/or ACPA positive, n (%) | 164 (89.1) | 176 (71.8) | <0.001 |
| Nulliparity, n (%) | 81 (44.0) | 126 (49.8) | 0.23 |
| Education level, years of education (SD) | 15.9 (3.5) | 15.0 (3.0) | 0.02 |
| Number of different DMARDs prescribed prior to inclusion in the cohort (IQR) | 3 (2–4) | 2 (1–3) | <0.001 |
| Number of different csDMARDs prescribed prior to inclusion in the cohort (IQR) | 2 (2–3) | 2 (1–2) | <0.001 |
| Number of different bDMARDs prescribed prior to inclusion in the cohort (IQR) | 1 (0–2) | 0 (0–0) | <0.001 |
ACPA, anti-citrullinated protein antibody; bDMARDs, biologic disease-modifying antirheumatic drugs; csDMARDs, conventional synthetic disease-modifying antirheumatic drugs; DMARDs, disease-modifying antirheumatic drugs.