Table 5 Associations of ART with risk of ARM according to plurality of birth
Plurality of birth | ART | Population-based controls N (%) | All ARM cases | Prospectively collected ARM cases in 2009 to 2011 | ||||
|---|---|---|---|---|---|---|---|---|
N (%) | OR (95% CI) | P value | N (%) | OR (95% CI) | P value | |||
Singletons | No | 9,664,317 (99%) | 249 (94%) | 1.0 (Reference) | - | 116 (94%) | 1.0 (Reference) | - |
Yes | 81,039 (1%) | 16 (6%) | 7.7 (4.6–12.7) | <0.0001 | 7 (6%) | 7.2 (3.4–15.4) | <0.0001 | |
Multiple births | No | 275,687 (85%) | 16 (53%) | 1.0 (Reference) | - | 5 (42%) | 1.0 (Reference) | - |
Yes | 48,943 (15%) | 14 (47%) | 4.9 (2.4–10.1) | <0.0001 | 7 (58%) | 7.9 (2.5–24.9) | <0.0001 | |