ACTOMgSO4: Assessing whether prenatal magnesium sulphate given immediately prior to very preterm birth improves neurodevelopment in childhood - 6-8 year early school age follow-up (NHMRC funded).

This trial has completed recruitment. Followup is continuing.

Despite recent major advances in care around the time of birth that have led to large increases in the survival rates for very preterm babies, the rate of adverse long-term neurologic problems has not diminished in survivors, and remains too high compared with children not born too early.

We have just concluded a large clinical trial of magnesium sulphate, which was randomly given to one-half of mothers who were likely to deliver their baby too early (before 30 weeks of pregnancy). This trial was known as the ACTOMgSO4 study, and it recruited 1062 women from 16 centres in Australia and New Zealand; their pregnancies resulted in 1061 surviving children to 2 years of age. We have been able to show, for the first time, that magnesium sulphate was able to reduce the rate of substantial problems with gross motor function in 2-year-old survivors, from 6.6% to 3.4% (relative risk 0.51; 95% confidence interval 0.29, 0.91). There were also reductions in paediatric mortality to 2 years of age (17.1% to 13.8%), cerebral palsy in survivors (8.2% to 6.8%), and the combined outcome of death or cerebral palsy (24.0% to 19.8%). Although these latter differences were not quite statistically significant, they are potentially very important clinically. However, we are not sure if these improvements will translate into better and more important outcomes for the children as they grow older and reach school-age. As there are many examples of treatments given around the time of birth that have been shown to have some short-term benefits, but substantial long-term harms, we must be as certain as we can be that any advance in one small area of health is not counterbalanced by disadvantages in other health areas.

The aim of this study is to determine the outcome of 1061 survivors of the ACTOMgSO4 study at early school age (7-8 years of age), comparing the outcomes for those exposed to antenatal magnesium sulphate to those not so exposed.

References

Ananth CV, Vintzileos AM.Magnesium sulfate for preterm neuroprotection. JAMA. 2004 Feb 25;291(8):940; author reply 941. No abstract available.

Mittendorf R, Lee KS, Roizen NJ, Pryde PG.Magnesium sulfate for preterm neuroprotection. JAMA. 2004 Feb 25;291(8):940-1; author reply 941. No abstract available.

Crowther CA, Hiller JE, Doyle LW. Magnesium sulphate for preventing preterm birth in threatened preterm labour. Cochrane Database of Systematic Reviews 2002, Issue 4. Art. No.: CD001060. DOI: 10.1002/14651858.CD001060.

Crowther CA, Moore V. Magnesium maintenance therapy for preventing preterm birth after threatened preterm labour. Cochrane Database of Systematic Reviews 1998, Issue 1. Art. No.: CD000940. DOI: 10.1002/14651858.CD000940