Descriptive information on sociodemographic, fetal outcomes, delivery complications, AS-associated comorbidities and pharmacological exposures (from January 2006 to December 2009) in cases and controls
| Cases | Controls | Total | |||
|---|---|---|---|---|---|
| Number of deliveries | 388 | 1082 | 1470 | ||
| Maternal age | |||||
| ≤19 | 3 | 0.8% | 2 | 0.2% | 5 |
| 20–24 | 29 | 7.5% | 75 | 6.9% | 104 |
| 25–29 | 83 | 21.4% | 353 | 32.6% | 436 |
| 30–34 | 151 | 38.9% | 483 | 44.6% | 634 |
| ≥35 | 122 | 31.4% | 169 | 15.6% | 291 |
| BMI | |||||
| Mean (SD) | 24.9 (4.17) | 24.5 (4.38) | |||
| 11.0–19.9 | 21 | 5.4% | 87 | 8.0% | 108 |
| 20.0–24.9 | 185 | 47.7% | 520 | 48.1% | 705 |
| 25.0–29.9 | 99 | 25.5% | 245 | 22.6% | 344 |
| 30.0–60.0 | 41 | 10.6% | 110 | 10.2% | 151 |
| Missing | 42 | 10.8% | 120 | 11.1% | 162 |
| Smoking | |||||
| Yes | 32 | 8.2% | 85 | 7.9% | 117 |
| No | 335 | 86.3% | 946 | 87.4% | 1281 |
| Missing | 21 | 5.4% | 51 | 4.7% | 72 |
| Maternal education level | |||||
| <12 years | 195 | 50.3% | 500 | 46.2% | 695 |
| >12 years | 186 | 47.9% | 579 | 53.5% | 762 |
| Missing | 7 | 1.8% | 3 | 0.3% | 10 |
| Parity | |||||
| 1 child | 172 | 44.3% | 465 | 43.0% | 637 |
| >1 child | 216 | 55.7% | 617 | 57.0% | 833 |
| Comorbidities* | |||||
| IBD | 25 | 6.0% | 9 | 0.8% | 34 |
| Psoriasis | 15 | 4.0% | 4 | 0.4% | 19 |
| Peripheral arthritis and hip prosthesis | 39 | 10.0% | 2 | 0.2% | 41 |
| Renal disease | 11 | 3.0% | 7 | 0.6% | 18 |
| Diabetes mellitus† | 8 | 3.1% | 5 | 1.0% | 13 |
| Hypertension† | 10 | 3.9% | 10 | 2.1% | 20 |
| Pharmacological dispensation 12 months prior to delivery† | |||||
| NSAID | 64 | 24.9% | 20 | 4.2% | 84 |
| Corticosteroids | 36 | 14.0% | 1 | 0.2% | 37 |
| TNF | 12 | 4.7% | 0 | 0.0% | 12 |
| DMARD | 28 | 10.9% | 1 | 0.2% | 29 |
| SSZ | 25 | 9.7% | 0 | 0.0% | 25 |
| MTX | 2 | 0.8% | 0 | 0.0% | 2 |
| Other DMARD | 1 | 0.4% | 1 | 0.2% | 2 |
*Occurrence of comorbidity prior to delivery.
†Data 2006 and onwards based on 257 and 477 deliveries in cases and controls, respectively.
AS, ankylosing spondylitis; BMI, body mass index; DMARD, disease-modifying antirheumatic drug; IBD, inflammatory bowel disease, mtx, methotrexate; NSAID, non-steroidal anti-inflammatory drug; SSZ, salazopyrine; TNF, tumour necrosis factor.