Association between Serum Magnesium level and outcome in birth asphyxia

Association between Serum Magnesium level and outcome in birth asphyxia Gandhi K.1, Kumar Singh A.2*, Mehta A.3, Sharma B.4, Chandra Tiwari H.5 DOI: https://doi.org/10.17511/ijpr.2020.i07.08 1 Karm chand Gandhi, Senior Resident, Department of Pediatrics, BRD Medical College, Gorakhpur, Uttar Pradesh, India. 2* Abhishek Kumar Singh, Assistant Professor, Department of Pediatrics, BRD Medical College, Gorakhpur, Uttar Pradesh, India. 3 Anita Mehta, Professor and Head, Department of Pediatrics, BRD Medical College, Gorakhpur, Uttar Pradesh, India. 4 Bhoopendra Sharma, Professor, Department of Pediatrics, BRD Medical College, Gorakhpur, Uttar Pradesh, India. 5 Harish Chandra Tiwari, Assistant Professor, Department of Community Medicine, BRD Medical College, Gorakhpur, Uttar Pradesh, India.


Introduction
The neonatal seizure is the commonest neurological dysfunction in the neonatal period; it is a paroxysmal alternation in neurological function like motor behavior and/or autonomic function and can occur at any gestational age.
The Neonatal central nervous system is particularly susceptible to seizures due to a combination of   In the present study, hypomagnesemia was present in 4 patients out of 8 pts (50%) on day and day 3.

Results
There were no subjects who had hypomagnesemia on day 2.      No patient had an antenatal high-risk factor in mother who had hypomagnesemia; there was no significant association between high-risk factors and hypomagnesemia. In the present study, none of the patients had meningitis and hypomagnesemia; there was no significant association between meningitis and serum magnesium level.

Discussion
In the present study, 315 neonates with birth asphyxia were studied in 1 year. Both intramurally and extramurally delivered babies were included in this study. Hypomagnesemia was a significant cause of neonatal seizures. Most of the neonates with hypomagnesemia had associated hypocalcemia. It's necessary to estimate level supplementation has been suggested to have a neuroprotective function in developing the brain [16].

Gandhi KC. et al: Association between Serum Magnesium
Pediatric Review -International Journal of Pediatric Research 2020;7(7) There was a gradual rise in Mg levels with postnatal age, in both preterm infants with birth weights appropriate for gestational age and infants who were small for gestation age. Decreased Mg levels were observed in infants who were small gestational age and in infants born of toxemic mothers [17].
Higher average serum magnesium levels and decreased risk for long term abnormal motor examination (p = 0.037). A lower risk for epilepsy in the group with higher magnesium levels did not reach statistical significance (p = 0.06). This study demonstrates a correlation between higher neonatal magnesium levels and decreased risk for long term abnormal motor exam. Larger studies are needed to evaluate the hypothesis that of magnesium in addition to calcium in all neonates with seizures [18].
Magnesium sulfate administered antenatally has been found to reduce rates of cerebral palsy and given to the before preterm birth. [19].
Also delayed initiation of breastfeeding including decrease infant suckling behavior in the baby of an eclamptic mother [20]. Several animal model studies suggest that magnesium could play neuroprotective roles in the developing vertebrate CNS [21].
There are several neonatal complications (bradycardia, hypotonia, birth asphyxia, intubation in the delivery room, neonatal intensive care requirement) on increasing doses of magnesium sulfate in eclamptic mother are significantly related to increasing serum magnesium levels.
Overall, the low-dose magnesium sulfate regimen was safe in the management of eclamptic mothers, without toxicity to their neonates [22].
Gathwala et al randomly assigned forty terms, appropriate for gestational age babies with severe birth asphyxia (1 min Apgar score <3 and 5min Apgar score <6), to either the study group or the control group. They found that Mg levels at birth in the babies with birth asphyxia were not different from those reported in normal neonates.
Injection MgS04, administered in a dose of 250 mg/kg and 125 mg/kg as an intravenous infusion was safe, and the Mg levels obtained were in the range considered to be neuroprotective Similarly, Plasma Mg levels in babies with hypoxic-ischaemic encephalopathy are similar to those in normal neonates [23].
Bhat et al in their longitudinal randomized, placebocontrolled trial tested whether postnatal magnesium sulfate treatment could improve neurologic outcomes at discharge among term neonates with severe perinatal asphyxia.
The study subjects were 40 terms (> 37 weeks) neonates. Their findings demonstrate that postnatal treatment with magnesium sulfate improves neurologic outcomes at discharge for term neonates with HIE [24].
However, Galvin et al in his study suggested that magnesium treatment after perinatal HIE damage in the rat is not markedly neuroprotective for striatal medium spiny neurons [25].
A previous study in their prospective study of 60 term neonates with HIP suggested that serum total magnesium does not predict outcome in neonatal hypoxic-ischemic encephalopathy [26].
Elizabeth et al, from the cohort of 500 babies, measured total magnesium levels, and found significantly lower levels among LBW, lowest in preterm followed by term-LBW, compared to term controls [27]. Parathyroid hormone PTH is synthesized by the chief cells and stored in secretory granules. Serum PTH concentrations increase postnatally coincidentally with the fall in serum Ca in both term and preterm infants [28][29][30].
It has a significant circadian periodicity, spontaneous episodic pulsatility, with distinct peak property and a significant temporal coupling with serum iCa and P concentrations and prolactin secretion. In physiologic terms, PTH acts synergistically with 1,25 (OH)2D and is the most important regulation of extracellular Ca concentration.
PTH acts directly on bone and kidney and indirectly with the fall in serum Ca in both term and preterm infants [31][32][33][34]. It has a significant circadian periodicity, spontaneous episodic pulsatility, with distinct peak property and a significant temporal coupling with serum iCa and P concentrations and prolactin secretion.
In physiologic terms, PTH acts synergistically with 1,25 (OH)2D and is the most important regulation of extracellular Ca concentration. PTH acts directly on bone and kidney and indirectly on intestine that is PTH-induced mobilization of Ca from bone and increased renal distal tubular reabsorption of Ca and increased intestinal Ca absorption secondary to increased 1,25 (OH)2D production.

Gandhi KC. et al: Association between Serum Magnesium
Pediatric Review -International Journal of Pediatric Research 2020;7(7) A decrease in serum magnesium stimulates PTH secretion, although chronic hypomagnesemia inhibits secretions of PTH. Hypomagnesemia is also associated with an increased target tissue resistance to PTH probably from inactivity of adenylate cyclase, an Mg requiring enzyme.

Hypomagnesemia
Hypomagnesemia is present when serum total magnesium is less than 0.6 mmol/L (1.5 mg/dL). In the present study, severe birth asphyxia had more hypomagnesemia as in other studies done by Nasreen Khalesi et al which suggested birth asphyxia had more hypomagnesemia [39]. The result of the study was similar to the present study.

Conclusion
From the results obtained in the current study, it can be concluded that hypomagnesemia was more on day 1 and day 3. Severe birth asphyxia had more prevalence of Hypomagnesaemia.
What does the study add to the existing knowledge There have not been a lot of studies regarding the prevalence of hypomagnesemia and the association of hypomagnesemia with age gender, complications risk factor, and other electrolytes.
In previous studies, the role of therapeutic magnesium supplementation has been seen but not recommended so it is recommended that there should be more studies regarding hypomagnesemia in birth asphyxia and the association of hypomagnesemia with other parameters.