The occurrences and relative risks for fetal outcomes and delivery complications among women with AS versus controls expressed as frequencies and both crude and adjusted ORs for possible confounders
| Fetal outcomes | Cases (N=388) | Controls (N=1082) | Total | OR (95% CI) | Adjusted OR* (95% CI) |
|---|---|---|---|---|---|
| Preterm birth (< week 37) | 35 (9.0%) | 53 (4.9%) | 88 | 1.92 (1.17 to 3.15) | 1.82 (1.10 to 3.01) |
| Gestational week 32–36 | 29 (7.5%) | 48 (4.4%) | 77 | 1.74 (1.02 to 2.96) | 1.69 (0.98 to 2.91) |
| Gestational week <32 | 6 (1.5%) | 5 (0.5%) | 11 | 3.38 (1.03 to 11.1) | 2.85 (0.83 to 9.81) |
| 5 min Apgar <7 | 7 (1.8%) | 16 (1.5%) | 23 | 1.22 (0.50 to 2.96) | 0.98 (0.37 to 2.59) |
| SGA | 12 (3.1%) | 16 (1.5%) | 28 | 2.12 (1.00 to 4.50) | 1.96 (0.92 to 4.20) |
| LGA | 12 (3.1%) | 43 (4.0%) | 55 | 0.77 (0.32 to 1.82) | 0.69 (0.28 to 1.68) |
| Stillbirth | 1 (0.3%) | 1 (0.1%) | 2 | 2.79 (0.18 to 44.5) | NA |
| Pre-eclampsia | 17 (4.4%) | 28 (2.6%) | 45 | 1.72 (0.92 to 3.23) | 1.56 (0.80 to 3.05) |
| Delivery complications | |||||
| Epidural analgesia | 103 (26.5%) | 283 (26.2%) | 386 | 1.02 (0.78 to 1.34) | 1.06 (0.78 to 1.44) |
| CS | 112 (28.9%)† | 177 (16.4%)‡ | 289 | 2.07 (1.53 to 2.82) | 1.91 (1.39 to 2.63) |
| Elective CS | 64 (16.5%) | 70 (6.5%) | 134 | 3.00 (2.01 to 4.46) | 2.70 (1.77 to 4.11) |
| Emergency CS | 38 (9.8%) | 75 (6.9%) | 113 | 1.66 (1.09 to 2.54) | 1.56 (0.99 to 2.44) |
NA, not applicable.
*Adjusted for: maternal smoking, education level, age, age squared and parity.
†10 CS unspecified.
‡32 CS unspecified.
AS, ankylosing spondylitis; CS, Caesarean section; LGA, large for gestational age; SGA, small for gestational age.