28 April 2025
Evidence for the impact of a programme to increase the use of magnesium sulfate, a £5 injection that helps prevent cerebral palsy in premature babies, has been strengthened by a new study published in BMJ Quality and Safety.
The use of magnesium sulfate to prevent cerebral palsy has been recommended by NICE since 2015. Although maternity units were giving magnesium sulfate to some mothers in premature labour, many were not being given this important treatment. The programme, called PReCePT (Prevention of cerebral palsy in pre-term labour), was developed to address this issue.
It started in 2014 at University Hospitals Bristol and Weston NHS Foundation Trust (UHBW) in collaboration with Health Innovation West of England. Together they developed PReCePT with maternity staff and parents to increase the use of magnesium sulfate in the maternity unit at St Michael’s Hospital, and then other maternity units in the South West.
PReCePT provided practical tools, guidelines, and training to support hospital staff to give magnesium sulfate to eligible mothers. The programme was rolled out to all maternity units in England in 2018.
NIHR ARC West has been evaluation partner for PReCePT throughout its development and roll-out.
In this most recent study, ARC West researchers evaluated the effectiveness and cost-effectiveness of the national PReCePT programme roll out from 2018-2022. They compared magnesium sulfate use in maternity units in 2018-22 (after the programme), with its use in 2017 (before the programme).
They used data from the UK National Neonatal Research Database. This is a reliable database with high-quality information about babies born preterm and admitted to an NHS neonatal unit.
They accounted for factors such as:
They also investigated whether the COVID-19 pandemic had an effect on use of magnesium sulfate. Finally, they also looked at how magnesium sulfate was being used in Scotland and Wales, to see if what had been happening there was similar or different to what had been happening in England.
The researchers found that in England, magnesium sulfate use improved from about 66% in 2017 (the year before PReCePT) to about 86% in 2022 (four years after PReCePT).
After accounting for other things that might have changed over time, they estimated that PReCePT itself was responsible for about 6 percentage points (or about a third) of this total 20 percentage points improvement. This is an estimate, but the statistical analysis showed that we can be confident that the real amount of improvement due to PReCePT is likely to be between about 3 and 9 percentage points. They did several different ‘sensitivity’ analyses to check if the results changed when they made different assumptions about the effect of other factors. All of these results were very similar to the main analysis, which gives more reason to trust the results. All this means that we have strong evidence that the PReCePT programme helped more mothers and babies receive this important treatment.
After balancing out the costs of running the PReCePT programme and giving magnesium sulfate, against the cost-savings from preventing cerebral palsy in all the babies who had been treated, they estimated that the National PReCePT Programme had a ‘net monetary benefit’ of £597,000. This means that it saved more money than it costed, which is a good thing.
When they looked at just what had been happening since the COVID-19 pandemic in 2020, it looked like magnesium sulfate use might have been declining slightly over this period. Use of antenatal steroids, another protective treatment for preterm babies, also appeared to have been declining the same amount since the pandemic. It makes sense that the pandemic could have had a negative effect on quality of maternity care, as it had a negative effect on so many other aspects of healthcare. This more recent trend is concerning.
When they looked at what had been happening in Scotland and Wales, it looked like by 2022 all three nations were at similar levels, with around 80-85% of eligible mothers being treated. However, it also looked like after the PReCePT programme, use in England had accelerated faster than in Scotland and Wales, meaning that more mothers and babies were protected sooner.
Karen Luyt, Professor in Neonatal Medicine at the University of Bristol, Chief Investigator for PReCePT and Consultant Neonatologist at St Michael’s Hospital, Bristol, said:
“This study demonstrates that the national PReCePT programme accelerated the uptake of evidence-based treatment into routine practice. PReCePT was a collaborative and co-ordinated perinatal implementation programme supporting every hospital in England. This evaluation shows it enabled and sustained equitable health benefits for babies and ultimately reduced lifetime costs to society.”