Table 3. Secondary Outcomes for Live-Born Infants During the Birth Hospitalizationa.
| No./total (%) | Risk difference (95% CI), % | Relative risk (95% CI) | P valueb | |||
|---|---|---|---|---|---|---|
| Magnesium sulfate | Placebo | Unadjusted | Adjustedb | |||
| Gestational age at birth, mean (SD), wk | 32.4 (1.5) [n = 858] | 32.3 (1.4) [n = 821] | 0.07 (−0.08 to 0.22)c | NE | 0.09 (−0.02 to 0.20)c | .12 |
| Composite serious health outcomed | 81/384 (21) | 99/420 (24) | −1.98 (−7.87 to 3.91) | 0.91 (0.70 to 1.19) | 0.95 (0.72 to 1.23) | .68 |
| Intraventricular hemorrhage | ||||||
| Anye | 56/854 (6.6) | 55/818 (6.7) | −0.02 (−2.47 to 2.42) | 1.00 (0.69 to 1.44) | 0.97 (0.68 to 1.39) | .88 |
| Severe (grade 3 or 4) | 3/854 (0.4) | 3/818 (0.4) | −0.02 (−0.59 to 0.56) | NE | NE | >.99f |
| Cystic periventricular leukomalacia | 2/854 (0.2) | 6/818 (0.7) | −0.50 (−1.17 to 0.17) | NE | NE | .17f |
| Neonatal encephalopathy | 1/858 (0.1) | 1/821 (0.1) | −0.01 (−0.34 to 0.33) | NE | NE | >.99f |
| Neonatal convulsions | 7/858 (0.8) | 3/821 (0.4) | 0.45 (−0.28 to 1.18) | NE | NE | .34f |
| Proven necrotizing enterocolitisg | 2/858 (0.2) | 1/821 (0.1) | 0.11 (−0.29 to 0.51) | NE | NE | >.99f |
| Retinopathy of prematurity | ||||||
| Any requiring treatment | 23/265 (8.7) | 30/282 (11) | −1.57 (−6.74 to 3.61) | 0.85 (0.50 to 1.44) | 0.89 (0.54 to 1.48) | .66 |
| Severe (stage 3 or worse in better eye) | 3/266 (1.1) | 2/284 (0.7) | 0.42 (−1.18 to 2.03) | NE | NE | .68f |
| Patent ductus arteriosus requiring treatment | 8/858 (0.93) | 15/821 (1.83) | −0.85 (−2.00 to 0.31) | 0.52 (0.21 to 1.26) | 0.46 (0.19 to 1.13) | .09 |
| Neonatal respiratory distress syndromeh | 294/858 (34) | 334/821 (41) | −5.92 (−10.75 to −1.11) | 0.85 (0.75 to 0.97) | 0.85 (0.76 to 0.95) | .01 |
| Severity of respiratory diseasei | ||||||
| None | 564/858 (66) | 487/821 (59) | ||||
| Mild | 124/858 (14) | 136/821 (17) | −5.92 (−10.75 to −1.11) | 0.85 (0.75 to 0.97) | 0.85 (0.76 to 0.95) | .01 |
| Moderate | 141/858 (16) | 166/821 (20) | −4.13 (−8.26 to 0) | 0.83 (0.69 to 1.00) | 0.81 (0.68 to 0.97) | .02 |
| Severe | 29/858 (3) | 32/821 (4) | −0.31 (−2.19 to 1.56) | 0.92 (0.55 to 1.53) | 0.89 (0.54 to 1.47) | .64 |
| Use of oxygen therapy | 332/858 (39) | 375/821 (46) | −6.63 (−11.55 to −1.71) | 0.85 (0.76 to 0.96) | 0.86 (0.77 to 0.96) | .01 |
| Chronic lung diseasej | 48/858 (5.6) | 67/821 (8.2) | −2.39 (−4.88 to 0.11) | 0.70 (0.49 to 1.01) | 0.69 (0.48 to 0.99) | .04 |
| Required oxygen when discharged homek | 8/853 (0.9) | 18/817 (2.2) | −1.26 (−2.46 to −0.07) | 0.43 (0.19 to 0.97) | 0.43 (0.19 to 0.98) | .04 |
| Use of respiratory support | 533/858 (62) | 535/821 (65) | −3.32 (−8.15 to 1.51) | 0.95 (0.88 to 1.02) | 0.96 (0.91 to 1.02) | .19 |
| Air leak syndromek | 9/858 (1.0) | 14/821 (1.7) | −0.65 (−1.77 to 0.46) | 0.62 (0.27 to 1.42) | 0.62 (0.27 to 1.41) | .25 |
| Proven infectionl | ||||||
| Within first 48 h | 4/858 (0.5) | 3/821 (0.4) | 0.10 (−0.51 to 0.72) | NE | NE | >.99f |
| After first 48 h | 14/858 (1.6) | 13/821 (1.6) | 0.05 (−1.16 to 1.25) | 1.03 (0.49 to 2.18) | 1.04 (0.50 to 2.18) | .92 |
Abbreviation: NE, not estimable.
The analyses accounted for a within-participant clustering effect. The secondary outcomes of weight, length, and head circumference appear in eTable 5 in Supplement 3.
Adjusted for hospital site, gestational age at entry, and plurality.
Expressed as mean difference (95% CI).
Stillbirth, death of live-born infant before hospital discharge, severe respiratory disease, severe intraventricular hemorrhage, chronic lung disease, proven necrotizing enterocolitis, severe retinopathy of prematurity, or cystic periventricular leukomalacia.
Identified from cranial ultrasound within the first 7 days.
Calculated using the Fisher exact test.
Defined as at least 1 of the following: diagnosis at surgery or post mortem; radiological diagnosis with a clinical history plus pneumatosis intestinalis, or portal vein gas, or a persistent dilated loop on serial x-rays; or a clinical history plus abdominal wall cellulitis and palpable abdominal mass.
Defined as increasing respiratory distress or oxygen requirements or need for ventilatory support from the first 6 hours of life with a chest x-ray showing generalized reticular granular pattern.
Data are from separate log-binomial models (ie, mild, moderate, or severe vs none, moderate, or severe vs none or mild; and severe vs none, mild, or moderate) because a proportional odds assumption was not met.
Oxygen dependent at 36 weeks’ gestation or 28 days of life if born after 32 weeks’ gestation.
Adjusted for gestational age at entry and plurality.
Infection confirmed by culture.