Descriptive statistics of study population.
| Baseline Characteristics | N = 249 Pregnancies |
|---|---|
| Maternal age at delivery, mean (SD), yrs | 32.8 (3.8) |
| Duration RA at baseline, median (IQR), yrs | 4.9 (2.2–9.8) |
| DAS28, 3rd trimester, mean (SD) | 3.4 (1.1) |
| DAS28-CRP, 3rd trimester# | |
| < 2.6 (remission) | 72 (28.9) |
| ≥ 2.6 to < 3.2 (low disease activity) | 43 (17.2) |
| ≥ 3.2 to ≤ 5.1 (intermediate disease activity) | 118 (47.4) |
| > 5.1 (high disease activity) | 16 (6.4) |
| HAQ, 3rd trimester, median (IQR) | 0.75 (0.25–1.25) |
| Parity | |
| Nulliparous (no previous offspring) | 124 (51.5) |
| Multiparous (≥ 1 previous offspring) | 117 (48.5) |
| RA-associated autoantibodies | |
| Either RF- or ACPA-positive, or both positive | 186 (74.7) |
| Both negative | 63 (25.3) |
| RF-positive | 172 (69.1) |
| ACPA-positive | 153 (61.5) |
| Presence of erosions | 150 (60.2) |
| Methotrexate use in the past | 143 (57.4) |
| Biological agent use in the past | 44 (17.7) |
| Medication use during 3rd trimester | |
| Prednisone only | 63 (25.3) |
| Sulfasalazine only | 37 (14.9) |
| Both prednisone and sulfasalazine | 22 (8.8) |
| Hydroxychloroquine (either alone or in combination) | 4 (1.6) |
| No medication during 3rd trimester | 123 (49.4) |
| SES based on educational level | |
| Low | 16 (6.4) |
| Middle | 79 (31.7) |
| High | 131 (52.6) |
| Unknown | 23 (9.2) |
| Smoking$ | 22 (8.8) |
Values are n (%) unless indicated otherwise. Normally distributed data are presented as mean (SD); non-normally distributed data are presented as median (IQR).
↵# Disease activity groups are defined according to the European League Against Rheumatism criteria.
↵$ Smoking periconceptional or during pregnancy. RA: rheumatoid arthritis; IQR: interquartile range; DAS28: 28-joint count Disease Activity Score; DAS28-CRP3: DAS28 using C-reactive protein levels; RF: rheumatoid factor; ACPA: anticitrullinated protein antibody; SES: socioeconomic status; HAQ: Health Assessment Questionnaire.