Risk ratio (95% CI) |
|
Preterm birth (< 37 v. 37–41 wk) | 1.49 (1.32 to 1.66) | 1.57 (1.56 to 1.58) | 0.3 | 1.46 (1.29 to 1.63) | 1.41 (1.40 to 1.42) | 0.5 | 1.60 (1.39 to 1.81) | 1.45 (1.44 to 1.47) | 0.1 |
|
Very preterm birth (< 32 v. 32–41 wk) | 2.70 (1.95 to 3.44) | 2.81 (2.77 to 2.86) | 0.8 | 2.61 (1.88 to 3.35) | 2.36 (2.31 to 2.40) | 0.5 | 2.62 (1.83 to 3.41) | 2.43 (2.36 to 2.52) | 0.6 |
|
Risk difference (95% CI) |
|
Preterm birth (< 37 v. 37–41 wk) | 2.94 (1.91 to 3.96) | 4.63 (4.56 to 4.70) | 0.003 | 2.76 (1.74 to 3.78) | 3.41 (3.33 to 3.48) | 0.2 | 3.59 (2.32 to 4.85) | 3.57 (3.43 to 3.70) | 1.0 |
|
Very preterm birth (< 32 v. 32–41 wk) | 1.22 (0.71 to 1.73) | 1.67 (1.64 to 1.70) | 0.08 | 1.16 (0.66 to 1.67) | 1.31 (1.28 to 1.35) | 0.6 | 1.17 (0.62 to 1.71) | 1.32 (1.25 to 1.38) | 0.6 |