Clinical characteristics of axSpA and PsA, and grouped according to disease activity in the third trimester, reported as n (%) unless specified as mean (SD)
| Characteristic | SpA (total) | Inactive axSpA* BASDAI <4 | Active axSpA* BASDAI ≥4 | diff† (p value‡) | PsA (total) | Inactive PsA* DAS28 <2.6 | Active PsA* DAS28 ≥2.6 | diff† (p value‡) |
| Singleton births 2010–2019 | 312 | 131 | 114 | 121 | 64 | 27 | ||
| Educational level | ||||||||
| Low (<14 years) | 100 (33.2) | 35 (27.6) | 36 (32.7) | 5.1 (0.47) | 50 (42.0) | 22 (34.9) | 19 (73.1) | 38.2 (0.002) |
| High (≥14 years) | 201 (66.8) | 92 (72.4) | 74 (67.3) | 69 (58.0) | 41 (65.1) | 7 (26.9) | ||
| Missing | 11 | 4 | 4 | 2 | 1 | 1 | ||
| Disease criteria fulfilled‡ | 272 (94.4) | 114 (3.4) | 105 (99.1) | 5.7 (0.03§) | 105 (94.6) | 57 (95.0) | 23 (100) | 5.0 (0.32§) |
| Missing | 24 | 9 | 8 | 10 | 4 | 4 | ||
| Disease duration mean (SD) | 5.2 (4.3) | 5.8 (4.3) | 4.3 (3.9) | 1.5 (0.01) | 6.6 (5.3) | 6.9 (5.7) | 5.2 (3.5) | 1.7 (0.18) |
| Missing | 58 | 19 | 21 | 22 | ||||
| Prednisolon* | 11 (3.9) | 4 (3.3) | 4 (3.7) | 0.4 (0.87§) | 9 (8.8) | 6 (10.0) | 3 (11.5) | 1.5 (0.87§) |
| Missing | 29 | 9 | 5 | 19 | 4 | 1 | ||
| Sulfasalazine* | 15 (5.3) | 4 (3.3) | 9 (8.3) | 5.0 (0.12§) | 7 (6.9) | 5 (8.3) | 2 (7.7) | 0.6 (1.0§) |
| Missing | 29 | 9 | 5 | 19 | 4 | 1 | ||
| TNFi* | 12 (4.3) | 10 (8.3) | 1 (0.9) | 7.4 (0.01§) | 3 (2.9) | 2 (3.3) | none | 3.3 (0.42§) |
| Missing | 30 | 10 | 5 | 19 | 4 | 1 | ||
| TNFi pregnancy | 63 (26.0) | 34 (33.0) | 22 (22.9) | 10.1 (0.15) | 27 (26.2) | 15 (26.8) | 6 (25.0) | 1.8 (1.0) |
| Missing | 70 | 28 | 18 | 19 | 8 | 3 | ||
| Bodily pain* mean (SD) | 47.4 (27.5) | 63.5 (23.5) | 27.8 (16.9) | 28.9 (<0.001) | 58.0 (27.2) | 62.1 (26.0) | 46.8 (27.2) | 15.3 (0.017) |
| Missing | 64 | 10 | 7 | 32 | 5 | 2 | ||
| Physical function* mean (SD) | 52.6 (28.4) | 67.0 (22.9) | 35.2 (24.8) | 32.4 (<0.001) | 62.5 (26.9) | 69.0 (25.8) | 45.7 (21.7) | 23.3 (<0.001) |
| Missing | 61 | 10 | 4 | 31 | 4 | 2 | ||
| General health* mean (SD) | 51.1 (24.2) | 62.5 | 37.4 | 26.0 (<0.001) | 54.5 (18.6) | 58.3 | 45.3 | 13.0 (0.004) |
| Missing | 62 | 10 | 4 | 31 | 4 | 2 | ||
| Mental health* mean (SD) | 75.1 (14.7) | 81.0 (11.9) | 68.0 (14.8) | 11.2 (0.007) | 77.1 (15.3) | 78.4 (13.8) | 73.0 (17.9) | 5.4 (0.14) |
| Missing | 63 | 11 | 5 | 33 | 6 | 2 | ||
| Vitality* mean (SD) | 32.1 (21.3) | 40.2 (21.7) | 22.5 (16.2) | 20.4 (0.005) | 39.2 (22.1) | 41.7 (23.0) | 33.4 (17.9) | 8.3 (0.11) |
| Missing | 62 | 10 | 5 | 33 | 5 | 2 |
*In third trimester.
†Diff = differences in proportions for dichotomous and mean difference for continuous variables.
‡P value for active compared to inactive disease.
§The unconditional z-pooled test.
axSpA, axial spondyloarthritis; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; DAS-28, Disease Activity Score 28; PsA, psoriatic arthritis.