Different magnesium sulphate regimens given to women at risk of preterm birth to help protect the baby’s brain and improve long-term outcomes

This review found that not enough research has been carried out to show what is the best dose of, and how best to provide, magnesium sulphate to mothers prior to very preterm birth to protect the baby’s brain 

Babies born early (preterm) are at an increased risk of dying, and those who survive are at risk of damage to the brain that may lead to cerebral palsy (a disorder that affects the ability to move normally), blindness, deafness or other disability. Magnesium is an important mineral essential for good health and normal body and brain function. High-quality evidence from a Cochrane review shows that giving magnesium sulphate therapy to the mother before birth can help protect the preterm baby’s brain and improve long-term outcomes for the infant as it grows.

Magnesium sulphate is given in different doses and in different ways. There are some adverse effects for the mother during therapy such as flushing, warmth, sweating, nausea and vomiting, which may vary by the dose and way the magnesium sulphate is given. Since there is no clear and agreed best way, hospitals may vary in how they give magnesium sulphate. We found no completed randomised trials comparing different magnesium sulphate regimens. Studies are needed to establish what is the best dose and best way to give the magnesium sulphate. The babies in these trials need to be followed up over a long period so that we can monitor the effects of magnesium on child development.

Authors' conclusions: 

Although strong evidence supports the use of antenatal magnesium sulphate for neuroprotection of the fetus prior to very preterm birth, no trials comparing different treatment regimens have been completed. Research should be directed towards comparisons of different dosages and other variations in regimens, evaluating both maternal and infant outcomes.

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Background: 

The effectiveness of antenatal magnesium sulphate for neuroprotection of the fetus, infant, and child prior to very preterm birth, when given to women considered at risk of preterm birth, has been established. There is currently no consensus as to the regimen to use in terms of the dose, duration, the use of repeat dosing and timing.

Objectives: 

To assess the comparative effectiveness and adverse effects of different magnesium sulphate regimens for neuroprotection of the fetus in women considered at risk of preterm birth.

Search strategy: 

We searched the Cochrane Pregnancy and Childbirth Group’s Trials Register (31 December 2011).

Selection criteria: 

Randomised trials comparing different magnesium sulphate regimens when used for neuroprotection of the fetus in women considered at risk of preterm birth. We planned to include cluster trials. We planned to exclude quasi-randomised trials and those with a crossover design. We planned to include trials published as full-text papers, along with those published in abstract form only.

Data collection and analysis: 

We planned that at least two review authors would assess trial eligibility.

Main results: 

No eligible completed trials were identified.