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Antenatal magnesium sulfate to prevent cerebral palsy
  1. Amy K Keir1,2,3,
  2. Emily Shepherd1,
  3. Sarah McIntyre4,
  4. Alice Rumbold1,2,
  5. Charlotte Groves3,
  6. Caroline Crowther5,
  7. Emily Joy Callander6
  1. 1 SAHMRI Women and Kids, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
  2. 2 Adelaide Medical School and the Robinson Research Institute, The University of Adelaide, Adelaide, South Australia, Australia
  3. 3 Women's and Babies' Division, Women's and Children's Hospital, Adelaide, North Adelaide, South Australia, Australia
  4. 4 Cerebral Palsy Alliance Research Institute, The University of Sydney, Sydney, New South Wales, Australia
  5. 5 Liggins Institute, The University of Auckland, Auckland, New Zealand
  6. 6 School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
  1. Correspondence to Dr Amy K Keir, SAHMRI Women and Kids, South Australian Health and Medical Research Institute, Adelaide 5006, South Australia, Australia; amy.keir{at}


Magnesium sulfate given to women before birth at <30 weeks’ gestation reduces the risk of cerebral palsy in their children. Our study aimed to assess the impact of a local quality improvement programme, primarily using plan-do-study-act cycles, to increase the use of antenatal magnesium sulfate. After implementing our quality improvement programme, an average of 86% of babies delivered at <30 weeks’ gestation were exposed to antenatal magnesium sulfate compared with a historical baseline rate of 63%. Our study strengthens the case for embedding quality improvement programmes in maternal perinatal care to reduce the impact of cerebral palsy on families and society.

  • health services research
  • neonatology

Data availability statement

Data (de-identified only) are available upon reasonable request.

Statistics from


Cerebral palsy (CP) affects 1 in 700 Australian children, with preterm birth being the leading risk factor for CP and with the risk increasing substantially with decreasing gestational age at birth. The impact of CP on affected individuals, families, carers and society more broadly is significant. As there is no cure for CP, prevention and reduction in severity are a top priority.1 2 Antenatal magnesium sulfate is one of only two interventions during pregnancy or the first month of life with high-certainty evidence for CP prevention. Maternal receipt of this fetal neuroprotective medication before preterm birth reduces the risk of death or CP (relative risk (RR) 0.85, 95% CI 0.74 to 0.98), and of CP alone (RR 0.68, 95% CI 0.54 to 0.87) for exposed preterm-born children.3 Despite this evidence of efficacy and cost-effectiveness,1 2 there remain persistent gaps in the implementation of magnesium sulfate into perinatal care. The Australian and New Zealand Neonatal Network (ANZNN) reported in 2017 that only 66% of infants born at less than 30 weeks’ gestation were exposed to antenatal magnesium sulfate.4 This is consistent with the coverage in our centre at the Women’s and Children’s Hospital in Adelaide, Australia, where an average of 63% of infants of the same gestation had antenatal exposure to magnesium sulfate (2013–2018). Our study aimed to improve use of antenatal magnesium sulfate using quality improvement (QI) methodology in a tertiary centre in South Australia.


Our QI programme aimed to build the capabilities of front-line clinicians working in perinatal care to identify reasons for limited use of antenatal magnesium sulfate and implement strategies to create and sustain practice change using established QI methodologies.


The Women’s and Children’s Hospital, Adelaide, South Australia, is a major obstetric, midwifery, neonatal and gynaecological service provider to South Australia, Northern Territory, and far western New South Wales and Victoria. Over 5000 babies are delivered at the centre each year. Within the hospital are a maternal–fetal medicine service and a level 6 neonatal unit with 17 neonatal intensive care beds and 35 special care beds. The neonatal unit is responsible for providing care to inborn babies and outborn babies requiring transfer for specialist care and averages 1400 admissions per year.


We formed a front-line, clinician-led QI programme initially focusing on increasing the use of antenatal magnesium sulfate for CP prevention. Core elements were based on the Evidence-based Practice for Improving Quality programme.5 6 The QI programme consisted of the following components:

  • Establishing a dedicated clinician-led QI team consisting of front-line healthcare professionals (neonatologist, midwife and neonatal nurse) with local clinical credibility.

  • Provision of QI training to and by the team to build local capability. The QI team were trained in and then subsequently mentored clinical colleagues in QI methodology through the delivery of 1-day QI methodology workshops across clinical areas in perinatal care, usage of QI tools (eg, process mapping, Pareto charting) and plan-do-study-act (PDSA) cycles.5 6

  • Undertaking an initial project by the clinician-led QI team on improving the use of antenatal magnesium sulfate.

Study of the interventions

We used PDSA cycles to iteratively identify, test and implement changes across perinatal care clinical settings in our centre, tailored to local contexts and capabilities. Our primary outcome was the proportion of babies born at <30 weeks’ gestation exposed to magnesium sulfate before delivery. To measure the impact of interventions undertaken in the PDSA cycles on the primary outcome, statistical process control (SPC) charts were generated using the QI Macros package in Microsoft Excel Version 16.49 (KnowWare International, Denver, Colorado). Centreline (mean) and control limits were calculated using SPC techniques conforming to P chart primary assumptions. Special cause was defined as eight consecutive points above or below the centreline or a single point outside the control limits.


The QI project was facilitated by the midwifery lead and a working group consisting of key stakeholders (medical, nursing and midwifery representatives from relevant clinical areas) to identify barriers to its administration. Following a process mapping session, 47 identified blocks to the administration of magnesium sulfate were found (online supplemental material process map). These were then narrowed down by the working group to five key blocks through multiphase voting, forming a Pareto chart (online supplemental material pareto chart). Successive PDSA cycles were undertaken to develop strategies to address these ‘top’ five blocks. These included (1) training and education (PDSA cycle 1); (2) identifying magnesium sulfate ‘champions’ in each clinical setting (PDSA cycle 2); (3) improving identification of gestational age during maternal admission (PDSA cycle 3); (4) development of additional visual prompts of gestational age (PDSA cycle 4); and (5) development of an escalation plan to ensure prescription of magnesium sulfate to eligible women (PDSA cycle 5). Further details on each PDSA cycle are provided in online supplemental material table 1S.


From October 2018 to March 2021, during the QI programme, 176 babies born at <30 weeks’ gestation had an average of 86% antenatal exposure to antenatal magnesium sulfate, compared with an average (historical) baseline rate of 63%. The control (P) chart in figure 1 displays the data for the entire measurement period with special cause variation present and figure 2 with the new baseline calculated.

Figure 1

Proportion of infants exposed to antenatal magnesium sulfate (P chart). Data shown with mean and control limits fixed from quarter 3 of 2018 at the start of the quality improvement programme; red dots indicate special cause variation. LCL, lower control limit; UCL, upper control limit.

Figure 2

Proportion of infants exposed to antenatal magnesium sulfate (P chart). Data shown with mean and control limits recalculated in quarter 3 of 2018 at the start of the quality improvement programme (process change). LCL, lower control limit; UCL, upper control limit.


Antenatal use of magnesium sulfate increased to an average of 86% of babies born at <30 weeks’ gestational age from October 2018 to March 2021, directly attributable to our QI programme. If we had continued at our historical baseline of 63% coverage, 110 babies would have had antenatal exposure, compared with our new level of performance at 151 babies (86%). Our findings demonstrate the need to continue to support front-line staff to integrate and use QI as part of routine healthcare delivery, both in terms of dedicated resources and protected time.

Our work demonstrates that what perinatal healthcare professionals believe is occurring in clinical practice is not always reflected in the care delivered. Active implementation strategies and ongoing review of progress regarding the adoption of new interventions are required. In a survey of perinatal clinicians across Australia and New Zealand, individuals estimated that 89% of eligible mothers received magnesium sulfate.7 Based on ANZNN data, the reality was closer to 60%–70%.4 We have shown that without further ongoing implementation investment, at a minimum of $A50 353 per year to allow for a dedicated QI facilitation role, rates are unlikely to reach and be maintained at 90%. The potential impact of increasing current magnesium sulfate use throughout Australia and New Zealand from 67% of eligible women at less than 30 weeks’ gestation4 to closer to 90% is significant.

Magnesium sulfate for women at risk of preterm birth can prevent CP. Using an established QI approach, our study demonstrates that gaps in delivering evidence-based practices to prevent CP can be addressed and sustained. If realised across Australia and beyond, this would represent a major benefit to families and society.

Data availability statement

Data (de-identified only) are available upon reasonable request.

Ethics statements

Patient consent for publication

Ethics approval

The study was approved by the Women's and Children's Hospital Network (approval number 1030A/6/2021).



  • Twitter @AmyKKeir, @EmilyCallander

  • Contributors AKK and EJC had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. Concept and design: AKK and EJC. Acquisition, analysis or interpretation of data: all authors. Drafting of the manuscript: AKK initial draft and then all authors. Critical revision of the manuscript for important intellectual content: all authors. Statistical analysis: EJC and AKK.

  • Funding The Health Services Charitable Gifts Board (HSCGB) generously funds the salary of the nursing and midwifery co-leads for the QI programme. AKK and EJC are in receipt of National Health and Medical Research Council (NHMRC) Fellowships (APP1161379 and APP1159536, respectively).

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.

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