Table 3 Influenza in relation to risk of pre-eclampsia, preterm birth, small for gestational age birth, and birthweight
|  | Without influenza, n = 1032 | With influenza, n = 226 |
|---|---|---|
Pre-eclampsia | ||
 Cases, n (%) | 29 (2.8) | 8 (3.5) |
 Crude OR (95% CI) | 1 (Ref) | 1.27 (0.57, 2.81) |
 Adjusted OR (95% CI)a | 1 (Ref) | 1.44 (0.64, 3.26) |
Preterm birth | ||
 Cases, n (%) | 35 (3.4) | 6 (2.7) |
 Crude OR (95% CI) | 1 (Ref) | 0.78 (0.32, 1.87) |
 Adjusted OR (95% CI)a | 1 (Ref) | 0.77 (0.32, 1.88) |
Small for gestational age birth | ||
 Cases, n (%) | 82 (7.9) | 21 (9.3) |
 Crude OR (95% CI) | 1 (Ref) | 1.19 (0.72, 1.96) |
 Adjusted OR (95% CI)a | 1 (Ref) | 1.35 (0.80, 2.28) |
Birth weight | ||
 10th percentile (g) | 2975 | 2898 |
 Difference in 10th percentile, β (95% CI)b | 1 (Ref) | 22 (− 130, 174) |
 50th percentile (g) | 3589 | 3614 |
 Difference in 50th percentile, β (95% CI)b | 1 (Ref) | −4 (− 74, 67) |