International disparities in use of antenatal magnesium sulfate and antenatal steroids for the preterm baby

Antenatal magnesium sulfate (MgSO₄) and antenatal steroids (ANS) are evidence-based interventions that reduce risk of cerebral palsy and respiratory complications in preterm babies. They are recommended in clinical guidelines internationally. However, we have limited information on how well they are being implemented. The present study is a secondary data analysis and review using routine neonatal data on babies born 24-32 weeks' gestation, from hospitals in the international Vermont Oxford Network (VON) dataset. It is supplemented with UK National Neonatal Research Database data, and a literature review. We describe international use of antenatal MgSO₄ and ANS, with focus on differences between high (HIC) versus middle-income (MIC) countries. VON data from 2024 on 45 619 infants across 1111 centers from the UK, Ireland, Austria, Switzerland, Italy, US, UAE, Brazil, South Africa, and India were included. Ireland and the UK had the highest rates of MgSO₄ administration (>80%); South Africa and the UAE had the lowest (33.6%, 44.5%). There was a significant difference by income status (mean 74.8% in HICs vs. 49.4% in MICs). This disparity does not appear to have reduced over time. ANS were used more, with less variation. The supplementary literature review (10 studies reporting on 288 631 infants) found comparable treatment rates to those reported in VON. Use of antenatal MgSO₄ and ANS varies considerably across countries. Uptake is significantly lower in these MICs, but variation is high even between these HICs. Further work should prioritize understanding why differences exist, and what can be done to make these key antenatal interventions more globally equitable.