Demographics at baseline (n=35) | |
Age, years (mean, SD) | 29.7 (2.62) |
Age>30 years, n (%) | 12 (34) |
Smoking status, n (%) | |
Never | 29 (83) |
Cessation>3 years | 2 (6) |
Cessation<3 years | 3 (9) |
Current smoker | 1 (3) |
Profession, n (%) | |
Physical labour | 6 (17) |
Non-physical labour | 27 (77) |
Unemployed/student | 2 (6) |
Clinical characteristics at baseline (n=35) | |
Weight, kg (mean, SD) | 68 (10.9) |
BMI, kg/m² (mean, SD) | 25 (3.7) |
Weight gain during pregnancy, kg (median, 95% CI) | 10 (9 to 10) |
HLA-B27 positivity, n (%) | 1 (3) |
Back pain symptoms, n (%) | 11 (31) |
Duration back pain, weeks (mean, SD)* | 13.8 (7.65) |
≥3 months of back pain (=chronic), n (%)* | 8 (73) |
VAS back pain at night (median, 95% CI)* | 0.5 (0 to 2) |
VAS back pain day and night (median, 95% CI)* | 1 (1 to 3) |
Insidious onset of back pain, n (%)* | 9 (82) |
Back pain improvement with exercise, n (%)* | 9 (82) |
No improvement of back pain with rest, n (%)* | 3 (27) |
Nocturnal back pain, n (%)* | 5 (46) |
Alternating buttock pain, n (%)* | 3 (27) |
Morning stiffness, n (%)* | 1 (9) |
Inflammatory back pain (ASAS criteria), n (%)* | 4 (36) |
Family history of SpA, n (%) | 2 (6) |
Arthritis (history or current), n | 0 |
Enthesitis (history or current), n | 0 |
Dactylitis (history or current), n | 0 |
Uveitis (history or current), n | 0 |
Psoriasis (history or current), n (%) | 3 (9) |
Inflammatory bowel disease (history or current), n | 0 |
Current pregnancy and delivery (n=35) | |
First pregnancy (G=1), n (%) | 18 (51) |
First delivery (P=1), n (%) | 22 (63) |
Duration of labour, hours (median, 95% CI) | 8 (6 to 12) |
Epidural anaesthesia, n (%) | 22 (63) |
Male newborn, n (%) | 17 (49) |
Weight newborn, g (mean, SD) | 3341 (502) |
Length newborn, cm (mean, SD) | 50 (2.4) |
Head circumference newborn, cm (mean, SD) | 34 (1.5) |
*Only those patients with back pain were retained.
ASAS, Assessment of SpondyloArthritis international Society; G, gravida; P, para; SpA, spondyloarthritis; VAS, visual analogue scale.