Descriptive statistics of women with RA included in the PreCARA cohort (N=171), PARA cohort (N=249) and the general population cohort (N=32 532*)
| Variable | PreCARA cohort | PARA cohort | General population | P value |
| Maternal age at delivery (years), mean (SD) | 31.7±3.9 | 32.8±3.8 | Unavailable | 0.050 |
| Disease duration at inclusion (years), median (IQR) | 6.5 (3.2–10.7) | 4.9 (2.2–9.8) | n/a | 0.032 |
| DAS28-CRP, third trimester, mean (SD) | 2.2±0.7 | 3.4±1.1 | n/a | <0.001 |
| DAS28-CRP, 12 weeks post partum, mean (SD) | 2.2+0.8 | 3.6±1.2 | n/a | <0.001 |
| HAQ, third trimester, median (IQR) | 0.50 (0.13–0.88) | 0.75 (0.25–1.25) | n/a | <0.001 |
| Nulliparity | 76 (44.4) | 124 (51.5) | 5412 (48) | 0.153 |
| RF and/or ACPA positive | 151 (88.3) | 186 (74.7) | n/a | <0.001 |
| Presence of erosions | 54 (31.6) | 150 (60.2) | n/a | <0.001 |
| Birth weight (g), mean (SD) | 3217±550 | 3324±594 | Unavailable | 0.063 |
| Birth weight <2500 g | 15 (8.8) | 23 (9.2) | 602 (5) | 0.888 |
| Preterm delivery (gestational age <37 weeks) | 19 (11.1) | 28 (11.2) | 692 (6) | 0.975 |
| Education level (years), median (IQR) | 16 (14–18) | 15 (13–17) | Unavailable | 0.001 |
| Smoking | 6 (3.5) | 22 (8.8) | Unavailable | 0.032 |
| Medication post partum†† | ||||
| Methotrexate | 44 (25.7) | 104 (41.8) | n/a | <0.001 |
| Prednisone | 69 (40.4) | 107 (43.0) | n/a | 0.596 |
| Hydroxychloroquine | 93 (54.5) | 24 (9.6) | n/a | <0.001 |
| Sulfasalazine | 101 (59.1) | 87 (34.9) | n/a | <0.001 |
| TNF inhibitors‡‡ | 80 (46.8) | 33 (13.3) | n/a | <0.001 |
| Tocilizumab | 9 (5.3) | 0 (0.0) | n/a | <0.001 |
| Golimumab | 1 (0.6) | 0 (0.0) | n/a | <0.001 |
| Abatacept | 2 (1.2) | 0 (0.0) | n/a | <0.001 |
| Azathioprine | 3 (1.8) | 4 (1.6%) | n/a | 0.876 |
| Leflunomide | 3 (1.8) | 3 (1.2) | n/a | 0.613 |
Values are numbers (%) unless indicated otherwise.
*Not all 32 532 participants were available at each time point.
†Any use during 6 months after delivery, either alone or in combination.
‡Certolizumab pegol, etanercept, adalimumab or infliximab.
ACPA, anticitrullinated protein antibody; DAS28-CRP, 28-joint count Disease Activity Score using C reactive protein levels; HAQ, Health Assessment Questionnaire; PARA, Pregnancy-iinduced Amelioration of Rheumatoid Arthritis; PreCARA, Preconceptional Counselling in Active Rheumatoid Arthritis; RA, rheumatoid arthritis; RF, rheumatoid factor; TNF, tumour necrosis factor.