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Meta-Analysis
. 2013 May 31;2013(5):CD000940.
doi: 10.1002/14651858.CD000940.pub3.

Magnesium maintenance therapy for preventing preterm birth after threatened preterm labour

Shanshan Han  1 , Caroline A Crowther, Vivienne Moore
Affiliations
Meta-Analysis

Magnesium maintenance therapy for preventing preterm birth after threatened preterm labour

Shanshan Han et al. Cochrane Database Syst Rev. .

Abstract

Background: Magnesium maintenance therapy is one of the types of tocolytic therapy used after an episode of threatened preterm labour (usually treated with an initial dose of tocolytic therapy) in an attempt to prevent the onset of further preterm contractions.

Objectives: To assess whether magnesium maintenance therapy is effective in preventing preterm birth after the initial threatened preterm labour is arrested.

Search methods: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 January 2013).

Selection criteria: Randomised controlled trials of magnesium therapy given to women after threatened preterm labour.

Data collection and analysis: The review authors independently assessed the studies for inclusion, assessed risk of bias and carried out data extraction. We checked data entry.

Main results: We included four trials involving 422 women. Three trials had high risk of bias and none included any long-term follow-up of infants. No differences in the incidence of preterm birth or perinatal mortality were seen when magnesium maintenance therapy was compared with placebo or no treatment; or alternative therapies (ritodrine or terbutaline). The risk ratio (RR) for preterm birth (less than 37 weeks) for magnesium compared with placebo or no treatment was 1.05, 95% confidence interval (CI) 0.80 to 1.40 (two trials, 99 women); and 0.99, 95% CI 0.57 to 1.72 (two trials, 100 women) for magnesium compared with alternative therapies. The RR for perinatal mortality for magnesium compared with placebo or no treatment was 5.00, 95% CI 0.25 to 99.16 (one trial, 50 infants); and 5.00, 95% CI 0.25 to 99.16 (one trial, 50 infants) for magnesium compared with alternative treatments.Women taking magnesium preparations were less likely to report side effects (RR 0.67, 95% CI 0.47 to 0.96, three trials, 237 women), including palpitations or tachycardia (RR 0.26, 95% CI 0.13 to 0.52, three trials, 237 women) than women receiving alternative therapies. Women receiving magnesium were however, more likely to experience diarrhoea (RR 6.79, 95% CI 1.26 to 36.72, three trials, 237 women).

Authors' conclusions: There is not enough evidence to show any difference between magnesium maintenance therapy compared with either placebo or no treatment, or alternative therapies (ritodrine or terbutaline) in preventing preterm birth after an episode of threatened preterm labour.

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Conflict of interest statement

Caroline Crowther was the principal investigator of the Australasian Collaborative Trial of Magnesium Sulphate for the Prevention of Mortality and Cerebral Palsy in Infants born very preterm. This multi‐centre randomised controlled trial assessed the effects of magnesium sulphate given to women expected to deliver a very preterm infant(s) (less than 30 weeks) within 24 hours. She is also principal investigator for the Magenta Trial assessing the use of antenatal magnesium sulphate for fetal neuroprotection immediately prior to birth in women between 30 and 34 weeks' gestation.

Figures

1
1
'Risk of bias' graph: review authors' judgements about each risk of bias item presented as percentages across all included studies.
2
2
'Risk of bias' summary: review authors' judgements about each risk of bias item for each included study.
1.1
1.1. Analysis
Comparison 1 Magnesium versus placebo or no treatment, Outcome 1 Preterm birth.
1.2
1.2. Analysis
Comparison 1 Magnesium versus placebo or no treatment, Outcome 2 Perinatal mortality.
1.3
1.3. Analysis
Comparison 1 Magnesium versus placebo or no treatment, Outcome 3 Maternal readmission for threatened preterm labour.
1.4
1.4. Analysis
Comparison 1 Magnesium versus placebo or no treatment, Outcome 4 Respiratory distress syndrome.
1.5
1.5. Analysis
Comparison 1 Magnesium versus placebo or no treatment, Outcome 5 Periventricular haemorrhage.
1.6
1.6. Analysis
Comparison 1 Magnesium versus placebo or no treatment, Outcome 6 Neonatal intensive care unit admissions.
1.7
1.7. Analysis
Comparison 1 Magnesium versus placebo or no treatment, Outcome 7 Neonatal length of stay (days).
1.8
1.8. Analysis
Comparison 1 Magnesium versus placebo or no treatment, Outcome 8 Gestational age at delivery (weeks).
1.9
1.9. Analysis
Comparison 1 Magnesium versus placebo or no treatment, Outcome 9 Maternal side effects.
2.1
2.1. Analysis
Comparison 2 Magnesium versus alternative treatment, Outcome 1 Preterm birth.
2.2
2.2. Analysis
Comparison 2 Magnesium versus alternative treatment, Outcome 2 Perinatal mortality.
2.3
2.3. Analysis
Comparison 2 Magnesium versus alternative treatment, Outcome 3 Maternal readmission for threatened preterm labour.
2.4
2.4. Analysis
Comparison 2 Magnesium versus alternative treatment, Outcome 4 Periventricular haemorrhage.
2.5
2.5. Analysis
Comparison 2 Magnesium versus alternative treatment, Outcome 5 Neonatal intensive care unit admissions.
2.6
2.6. Analysis
Comparison 2 Magnesium versus alternative treatment, Outcome 6 Neonatal length of stay (days).
2.7
2.7. Analysis
Comparison 2 Magnesium versus alternative treatment, Outcome 7 Gestational age at delivery (weeks).
2.8
2.8. Analysis
Comparison 2 Magnesium versus alternative treatment, Outcome 8 Maternal side effects.
See this image and copyright information in PMC

Update of

References

References to studies included in this review

Holcomb 1991 {published data only}
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Ricci 1991 {published data only}
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Ridgway 1990 {published data only}
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Facchinetti 1992 {published data only}
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