EARLY CEREBRAL NEUROPROTECTION BY MATERNALLY-ADMINISTERED MAGNESIUM SULFATE(MgSO₄) IN PRETERM INFANTS IS RELATED TO INITIAL POSTNATAL SERUM MAGNESIUM (Mg) LEVELS. 1504

INTRODUCTION: We have described a neuroprotective effect in premature infants by maternally-administered MgSO₄ in preventing early cerebral injury (Grades III and IV intracranial hemorrhage [ICH] and large[>5 mm] cystic periventricular leukomalacia [CPVL]). We speculated that the degree of neuroprotection may be related to maternal serum Mg level, duration of maternal therapy, or to initial serum Mg levels in the infants on day 1 of life. We performed this investigation to assess these hypotheses.METHODS: From 1991-1994, we prospectively followed 137 ventilated preterm infants (< 33 weeks gestational age) to evaluate acute cerebral injury and long-term neurodevelopmental outcome. 16/61 (26%) infants whose mothers received MgSO₄ prior to delivery developed Grade III or IV ICH or CPVL compared to 45/76 (59%) of infants whose mothers did not receive MgSO₄. 42/61 (69%) infants whose mothers received MgSO₄ had serum Mg levels drawn during the first 24 hours of life and comprise our study population. We ascertained the duration of maternal MgSO₄ therapy and their serum Mg levels prior to delivery. RESULTS: CONCLUSION: While there is no association with either duration of maternal therapy or maternal serum Mg levels, initial serum Mg levels in preterm infants directly correlate with prevention of Gr III/IV ICH and CPVL.SPECULATION: Factors positively affecting transplacental passage of Mg may optimize fetal and neonatal Mg levels to enhance neuroprotection.Supported by NIH 5RO1 HD21453-06 Table

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