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 | |
ART = assisted reproductive techniques, OR = odds ratio, CI = confidence interval.