factors associated with changes in magnesium levels in asymptomatic neonates: a longitudinal analysis

Background: neonates and infants with hypomagnesemia present with seizures and psychomotor delay. objectives: the present study evaluated the changes in magnesium (mg) levels and factors associated with these in the first three days of life. materials and methods: we monitored 50 clinically asymptomatic neonates; they were not given any magnesium supplements even if they had hypomagnesemia at baseline. the variables analysed were: serum mg; gestational age; birth weight; length; and the ponderal index. we used random effects (re) models for longitudinal analysis of these data. results: the mean standard deviation (sd) gestational age was 36.3 (3.6) weeks and the mean (sd) weight was 2604.2 (754.4) grams. about 31% of the neonates had hypomagnesemia (< 1.6 mg/dl) on day one; however, all had normal magnesium levels by day three of life (p < 0.001). at birth, after adjusting for intrauterine growth retardation status (iugr), serum mg levels were lower by 0.0097 mg/dl (95% ci: -0.019 to -0.0003) per 100 grams increase in weight of the neonate. after adjusting for iugr status, the mean increase in the serum mg levels was 0.14 mg/dl (95% confidence intervals [ci]: 0.10 to 0.18) per day. the per-day increase in magnesium levels was significantly higher in low birth weight babies (0.10, 95% ci: 0.01 to 0.18) compared with normal birth weight babies. conclusions: asymptomatic neonates may have a high prevalence of hypomagnesemia; however, the levels become normal without any magnesium supplementation. even though regular monitoring of magnesium levels is useful, no supplements are required - particularly in clinically asymptomatic neonates.