Table 3 Bivariate associations of ART and plurality with risk of ARM
Group | Population-based controls N (%) | All ARM cases | Prospectively collected ARM cases in 2009 to 2011 | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
N (%) | ORcrude(95% CI) | P value | N (%) | ORcrude(95% CI) | P value | ||||||
ART | No | 9,940,004 (99%) | 265 (90%) | 1.0 (Reference) | - | 121 (90%) | 1.0 (Reference) | - | |||
Yes | 129,982 (1%) | 30 (10%) | 8.7 (5.9–12.6) | <0.0001 | 14 (10%) | 8.8 (5.1–15.4) | <0.0001 | ||||
Plurality of birth | Singletons | 9,745,356 (97%) | 265 (90%) | 1.0 (Reference) | - | 123 (91%) | 1.0 (Reference) | - | |||
Multiple births | 324,630 (3%) | 30 (10%) | 3.4 (2.3–5.0) | <0.0001 | 12 (9%) | 2.9 (1.6–5.3) | 0.0002 | ||||
Isolated ARM cases | ARM cases with associated anomalies | VATER/VACTERL association | |||||||||
Group | Population-based controls N (%) | N (%) | OR crude (95% CI) | P value | N (%) | OR crude (95% CI) | P value | N (%) | OR crude (95% CI) | P value | |
ART | No | 9,940,004 (99%) | 124 (94%) | 1.0 (Reference) | - | 141 (87%) | 1.0 (Reference) | - | 58 (91%) | 1.0 (Reference) | - |
Yes | 129,982 (1%) | 8 (6%) | 4.9 (2.4–10.1) | <0.0001 | 22 (14%) | 11.9 (7.6–18.7) | <0.0001 | 6 (9%) | 7.9 (3.4–18.3) | <0.0001 | |
Plurality of birth | Singletons | 9,745,356 (97%) | 117 (89%) | 1.0 (Reference) | - | 148 (91%) | 1.0 (Reference) | - | 58 (91%) | 1.0 (Reference) | - |
Multiple births | 324,630 (3%) | 15 (11%) | 3.8 (2.2–6.6) | <0.0001 | 15 (9%) | 3.0 (1.8–5.2) | <0.0001 | 6 (9%) | 3.1 (1.3–7.2) | 0.005 | |