Magnesium sulfate for fetal neuroprotection?

Guidelines:
1 . For women with imminent preterm birth (≤ 31+6 weeks), antenatal
magnesium sulphate administration should be considered for fetal
neuroprotection . (I-A)
2 . For women with imminent preterm birth, antenatal magnesium
sulphate for fetal neuroprotection should be administered as
a 4g IV loading dose, over 30 minutes, followed by a 1g/hr
maintenance infusion until birth . (II-2B)
3 . For planned preterm birth for fetal or maternal indications,
magnesium sulphate should be started, ideally within 4 hours
before birth, as a 4g IV loading dose, over 30 minutes, followed by
a 1g/hr maintenance infusion until birth . (II-2B)
Ref: SOGC CLINICAL PRACTICE GUIDELINE: 2011