Short-term morbidities and neurodevelopmental outcomes in preterm infants exposed to magnesium sulphate treatment.

Aim: The aim of the study is to examine whether baseline serum Mg concentration has an impact on short-term and long-term outcomes in preterm infants exposed antenatally to MgSO4.

Methods: Participants included all infants admitted to the neonatal intensive care unit at <32 weeks of gestational age. Infant serum Mg concentration (iMgC) was examined immediately after birth in those exposed to maternal MgSO4. Data for short-term outcomes were collected from the infants' computerised charts. Neurodevelopmental outcomes at 6-12 months corrected age were assessed using the Griffiths Mental Developmental Scales.

Results: Of 197 eligible infants, 145 were exposed to MgSO4. Baseline iMgC was available for 88 infants. Mean iMgC was 3.5 ± 0.88 mg/dL (1.6-5.7 mg/dL). Baseline iMgC was not associated with an increased risk for neither early morbidities nor adverse long-term outcome. However, iMgC above the mean (>3.5 mg/dL) was associated with significantly lower scores on locomotor (P = 0.016) and personal-social (0.041) scales in the first year of life.

Conclusions: In a cohort of preterm infants antenatally exposed to MgSO4, elevated baseline iMgC (>3.5 mg/dL) was associated with lower locomotor scores. Further research is needed in order to study the relationship between supra-physiologic iMgC and its effect on the developing brain.