Table 3.
Stratified Analyses of the Primary Outcome and Its Components.*
| Outcome | Magnesium Sulfate (N=1041) | Placebo (N=1095) | Relative Risk (95% CI) |
|---|---|---|---|
| no./total no. (%) | |||
| Primary outcome | |||
| Weeks of gestation at randomization | |||
| <28 | 89/442 (20.1) | 105/496 (21.2) | 0.95 (0.74–1.22) |
| ≥28 | 29/599 (4.8) | 23/599 (3.8) | 1.26 (0.74–2.15) |
| Magnesium sulfate treatment before randomization | |||
| Yes | 27/192 (14.1) | 26/210 (12.4) | 1.14 (0.69–1.88) |
| No | 91/849 (10.7) | 102/885 (11.5) | 0.93 (0.71–1.21) |
| Singleton or twin pregnancy | |||
| Singleton | 97/950 (10.2) | 103/985 (10.5) | 0.98 (0.75–1.27) |
| Twin | 21/91 (23.1) | 25/110 (22.7) | 1.02 (0.61–1.69) |
| Moderate or severe cerebral palsy | |||
| Weeks of gestation at randomization | |||
| <28 | 12/442 (2.7) | 30/496 (6.0) | 0.45 (0.23–0.87) |
| ≥28 | 8/599 (1.3) | 8/599 (1.3) | 1.00 (0.38–2.65) |
| Magnesium sulfate treatment before randomization | |||
| Yes | 6/192 (3.1) | 11/210 (5.2) | 0.60 (0.23–1.58) |
| No | 14/849 (1.6) | 27/885 (3.1) | 0.54 (0.29–1.02) |
| Singleton or twin pregnancy | |||
| Singleton | 14/950 (1.5) | 28/985 (2.8) | 0.52 (0.27–0.98) |
| Twin | 6/91 (6.6) | 10/110 (9.1) | 0.73 (0.27–1.92) |
| Fetal or infant death | |||
| Weeks of gestation at randomization | |||
| <28 | 78/442 (17.6) | 78/496 (15.7) | 1.12 (0.84–1.49) |
| ≥28 | 21/599 (3.5) | 15/599 (2.5) | 1.40 (0.73–2.69) |
| Magnesium sulfate treatment before randomization | |||
| Yes | 21/192 (10.9) | 15/210 (7.1) | 1.53 (0.81–2.88) |
| No | 78/849 (9.2) | 78/885 (8.8) | 1.04 (0.77–1.41) |
| Singleton or twin pregnancy | |||
| Singleton | 83/950 (8.7) | 75/985 (7.6) | 1.15 (0.85–1.55) |
| Twin | 16/91 (17.6) | 18/110 (16.4) | 1.07 (0.58–1.98) |
*
The primary outcome was the composite of stillbirth or infant death by 1 year of corrected age or moderate or severe cerebral palsy at or beyond 2 years of corrected age. P>0.05 for all comparisons (Breslow–Day test).