Table 9. Neonatal secondary outcomes*.
| Outcome | Studies contributing data | MgSO4 | Control | RR | LCL | UCL | p† |
| Dichotomous | |||||||
| Apgar score < 7 at 5 minutes | 9,10,11,12,13 | 414/2,903 (14.3%) | 420/2,961 (14.2%) | 1.01 | 0.89 | 1.14 | 0.38 |
| Active resuscitation at birth | 9,10,12,13 | 1,218/2,836 (42.9%) | 1,284/2,891 (44.4%) | 0.99 | 0.96 | 1.02 | 0.46 |
| Respiratory distress syndrome | 9,10,11,13 | 1,288/2,215 (58.1%) | 1,325/2,268 (58.4%) | 1.01 | 0.97 | 1.05 | 0.46 |
| Ongoing use of respiratory support | 9,10,11,12,13 | 1,544/2,667 (57.9%) | 1,612/2,710 (59.5%) | 1.00 | 0.97 | 1.03 | 0.10 |
| Chronic lung disease/BPD | 9,10,11,13 | 442/2,223 (19.9%) | 420/2,273 (18.5%) | 1.08 | 0.96 | 1.22 | 0.56 |
| Neonatal convulsions | 9,10,11,12,13 | 68/2,884 (2.4%) | 89/2,930 (3.0%) | 0.75 | 0.54 | 1.03 | 0.91 |
| Any IVH | 9,10,11,13 | 461/2,149 (21.5%) | 482/2,202 (21.9%) | 0.98 | 0.87 | 1.09 | 0.37 |
| Grade 3 or 4 IVH | 9,10,11,13 | 96/2,149 (4.5%) | 114/2,202 (5.2%) | 0.83 | 0.63 | 1.09 | 0.48 |
| Cystic PVL | 9,10,11,13 | 70/2,044 (3.4%) | 76/2,089 (3.6%) | 0.91 | 0.66 | 1.25 | 0.90 |
| Posthaemorrhagic hydrocephaly or ventriculomegaly | 9,10,11 | 57/1,000 (5.7%) | 53/976 (5.4%) | 1.06 | 0.73 | 1.53 | 0.78 |
| Proven neonatal systemic infection | 9,10,11,13 | 432/2,213 (19.5%) | 417/2,266 (18.4%) | 1.06 | 0.94 | 1.20 | 0.47 |
| Necrotising enterocolitis | 9,10,11,13 | 155/2,142 (7.2%) | 131/2,190 (6.0%) | 1.22 | 0.97 | 1.53 | 0.56 |
| Patent ductus arteriosus requiring treatment | 9,10,11,13 | 425/2,214 (19.2%) | 432/2,264 (19.1%) | 1.03 | 0.91 | 1.16 | 0.50 |
| Any retinopathy of prematurity | 9,10,11,13 | 470/1,977 (23.8%) | 469/2,023 (23.2%) | 1.03 | 0.92 | 1.15 | 0.75 |
| Severe neonatal adverse outcome# | 9,10,11,13 | 1,021/2,225 (45.9%) | 1,011/2,282 (44.3%) | 1.03 | 0.97 | 1.10 | 0.44 |
| Continuous | Mean (SE) | Mean (SE) | Mean difference | LCL | UCL | p† | |
| Gestational age at birth (weeks) | 9,10,11,12,13 | 30.0 (29.8, 30.1)‡ (n = 2,996) | 29.9 (29.8, 30.1)‡ (n = 3,057) | 0.0 | −0.1 | 0.2 | 0.95 |
| Birth weight z-score | 9,10,11,12,13 | −0.25 (0.02) (n = 2,987) | −0.19 (0.02) (n = 3,047) | −0.05 | −0.10 | −0.00 | 0.82 |
| Birth weight (g)§ | 9,10,11,12,13 | 1,459 (12) (n = 2,987) | 1,471 (12) (n = 3,057) | −10 | −41 | 21 | 0.96 |
| Birth head circumference (cm)§ | 9,10,11,13 | 26.8 (0.1) (n = 2,038) | 26.8 (0.1) (n = 2,091) | 0.0 | −0.2 | 0.2 | 0.87 |
| Birth length (cm)§ | 9,10,11,13 | 38.4 (0.1) (n = 1,954) | 38.5 (0.1) (n = 2,009) | −0.0 | −0.3 | 0.3 | 0.85 |
Abbreviations: BPD, bronchopulmonary dysplasia; IVH, intraventricular haemorrhage; LCL, lower confidence limit; PVL, periventricular leucomalacia; RR, relative risk; SE, standard error; UCL, upper confidence limit. The trials included are as follows: 9 = Australasian Collaborative Trial of Magnesium Sulphate (ACTOMgSO4), 10 = PREterm brain protection by MAGnesium sulphate (PREMAG), 11 = Magnesium and Neurologic Endpoints Trial (MAGNET), 12 = MAGnesium sulphate for Prevention of Eclampsia (MAGPIE), and 13 = Beneficial Effects of Antenatal Magnesium Sulfate (BEAM).
*Overall results from 1-stage individual participant data (IPD).
#Any of the following: death, chronic lung disease, patent ductus arteriosus requiring treatment, neonatal encephalopathy, necrotising enterocolitis, stage 3 or worse retinopathy of prematurity, or grade 3 or 4 intraventricular haemorrhage (IVH).
†Heterogeneity p-values for 1-stage analyses.
§Adjusted for age and sex.