Effect of magnesium sulfate exposure on term neonates

Some Immune Parameters of Term Newborns at Birth Are Associated with the Concentration of Iron, Copper and Magnesium in Maternal Serum

The nutritional status of pregnant women is considered to affect fetal development and the health condition of newborns, including their immune system. We investigated the relationship between the concentrations of magnesium (Mg), calcium (Ca), zinc (Zn), iron (Fe) and copper (Cu) in maternal serum (MS) and the concentrations of IgG antibodies and antineutrophil cytoplasmatic auto-antibodies against lactoferrin (Lf-ANCA) in umbilical cord serum (UCS). IgG was considered as a promoter of immunity, and Lf-ANCA as an inhibitor. The examined group consisted of 98 pregnant women and their healthy term newborn children. The concentrations of mineral elements were measured by FAAS/FAES, while the concentrations of antibodies were determined by ELISA. Excessive MS Fe and insufficient MS Cu were related to insufficient UCS IgG and excessive UCS Lf-ANCA. The correlation analysis showed confirming results. Adequate UCS IgG and Lf-ANCA were related to MS Mg at the strictly lower limit of the reference values. The results obtained seem to suggest that an excess of Fe and a deficiency of Cu in pregnancy may adversely affect some immune parameters of newborns. Reference values for MS Mg are likely to require reconsideration. It would be advisable to monitor the nutritional status of pregnant women with minerals in order to support the immune capacity of newborns.

Fetal Neuroprotective Strategies: Therapeutic Agents and Their Underlying Synaptic Pathways

Synaptic signaling is integral for proper brain function. During fetal development, exposure to inflammation or mild hypoxic-ischemic insult may lead to synaptic changes and neurological damage that impairs future brain function. Preterm neonates are most susceptible to these deleterious outcomes. Evaluating clinically used and novel fetal neuroprotective measures is essential for expanding treatment options to mitigate the short and long-term consequences of fetal brain injury. Magnesium sulfate is a clinical fetal neuroprotective agent utilized in cases of imminent preterm birth. By blocking N-methyl-D-aspartate receptors, magnesium sulfate reduces glutamatergic signaling, which alters calcium influx, leading to a decrease in excitotoxicity. Emerging evidence suggests that melatonin and N-acetyl-L-cysteine (NAC) may also serve as novel putative fetal neuroprotective candidates. Melatonin has important anti-inflammatory and antioxidant properties and is a known mediator of synaptic plasticity and neuronal generation. While NAC acts as an antioxidant and a precursor to glutathione, it also modulates the glutamate system. Glutamate excitotoxicity and dysregulation can induce perinatal preterm brain injury through damage to maturing oligodendrocytes and neurons. The improved drug efficacy and delivery of the dendrimer-bound NAC conjugate provides an opportunity for enhanced pharmacological intervention. Here, we review recent literature on the synaptic pathways underlying these therapeutic strategies, discuss the current gaps in knowledge, and propose future directions for the field of fetal neuroprotective agents.

A randomized controlled trial on the use of magnesium sulfate and melatonin in neonatal hypoxic ischemic encephalopathy

BACKGROUND

Birth asphyxia is a leading case of neonatal morbidity and mortality especially in developing countries. Hypoxic-ischemic encephalopathy (HIE) attributed to asphyxia can be ameliorated with several remedies, although full recovery is currently not feasible. The aim of this trial on infants with HIE who are receiving melatonin therapy, is to assess the added effect of magnesium sulfate (MgSO4) on the expression of S100-B, a marker of brain injury.

METHODS

This study is a randomized controlled trial on neonates with moderate HIE (Sarnat grade II). Infants were randomized into 2 groups; group1 who received MgSO4 and melatonin; and group 2 who received melatonin only. Serum concentrations of S100-B were measured at baseline, and at days 2 and 6 of therapy.

RESULTS

The study included 60 neonates of them 30 infants in group 1 and 30 infants in group 2. S100-B did not differ between groups 1 and 2 at enrollment (median = 13.5 vs 13.2, p = 0.381). However, group 1 had lower concentrations of S100-B at 2 days (median = 8 vs 12, p = 0.001) and at 6 days (median = 3 vs 10.5, p < 0.001), respectively. Compared to baseline, S100-B decreased in in group 2 at day 6 (13.2 vs 10.5, p = 0.011) but did not decrease at day 2 (13.2 vs 12, p = 0.478).

CONCLUSIONS

MgSO4 may have an added effect for the reduction in brain injury in infants with HIE who are receiving melatonin.

Antenatal magnesium sulphate and adverse neonatal outcomes: A systematic review and meta-analysis

BACKGROUND

There is widespread, increasing use of magnesium sulphate in obstetric practice for pre-eclampsia, eclampsia, and preterm fetal neuroprotection; benefit for preventing preterm labour and birth (tocolysis) is unproven. We conducted a systematic review and meta-analysis to assess whether antenatal magnesium sulphate is associated with unintended adverse neonatal outcomes.

METHODS AND FINDINGS

CINAHL, Cochrane Library, LILACS, MEDLINE, Embase, TOXLINE, and Web of Science, were searched (inceptions to 3 September 2019). Randomised, quasi-randomised, and non-randomised trials, cohort and case-control studies, and case reports assessing antenatal magnesium sulphate for pre-eclampsia, eclampsia, fetal neuroprotection, or tocolysis, compared with placebo/no treatment or a different magnesium sulphate regimen, were included. The primary outcome was perinatal death. Secondary outcomes included pre-specified and non-pre-specified adverse neonatal outcomes. Two reviewers screened 5,890 articles, extracted data, and assessed risk of bias following Cochrane Handbook and RTI Item Bank guidance. For randomised trials, pooled risk ratios (RRs) or mean differences, with 95% confidence intervals (CIs), were calculated using fixed- or random-effects meta-analysis. Non-randomised data were tabulated and narratively summarised. We included 197 studies (40 randomised trials, 138 non-randomised studies, and 19 case reports), of mixed quality. The 40 trials (randomising 19,265 women and their babies) were conducted from 1987 to 2018 across high- (16 trials) and low/middle-income countries (23 trials) (1 mixed). Indications included pre-eclampsia/eclampsia (24 trials), fetal neuroprotection (7 trials), and tocolysis (9 trials); 18 trials compared magnesium sulphate with placebo/no treatment, and 22 compared different regimens. For perinatal death, no clear difference in randomised trials was observed between magnesium sulphate and placebo/no treatment (RR 1.01; 95% CI 0.92 to 1.10; 8 trials, 13,654 babies), nor between regimens. Eleven of 138 non-randomised studies reported on perinatal death. Only 1 cohort (127 babies; moderate to high risk of bias) observed an increased risk of perinatal death with >48 versus ≤48 grams magnesium sulphate exposure for tocolysis. No clear secondary adverse neonatal outcomes were observed in randomised trials, and a very limited number of possible adverse outcomes warranting further consideration were identified in non-randomised studies. Where non-randomised studies observed possible harms, often no or few confounders were controlled for (moderate to high risk of bias), samples were small (200 babies or fewer), and/or results were from subgroup analyses. Limitations include missing data for important outcomes across most studies, heterogeneity of included studies, and inclusion of published data only.

CONCLUSIONS

Our findings do not support clear associations between antenatal magnesium sulphate for beneficial indications and adverse neonatal outcomes. Further large, high-quality studies (prospective cohorts or individual participant data meta-analyses) assessing specific outcomes, or the impact of regimen, pregnancy, or birth characteristics on these outcomes, would further inform safety recommendations. PROSPERO: CRD42013004451.

Antenatal magnesium sulfate is beneficial or harmful in very preterm and extremely preterm neonates: a new insight

AIMS

To evaluate whether antenatal MgSO₄ is beneficial or harmful in very preterm and extremely preterm neonates.

MATERIALS AND METHODS

We retrieved published literature through searches of PubMed or Medline, CINAHL, and the Cochrane Library. Results were restricted to systematic reviews, meta-analysis, randomized controlled trials (RCTs), and relevant observational studies.

RESULTS

Evidence revealed that antenatal MgSO₄ has neuroprotective role in preterm neonates and it decreased the risk of cerebral palsy and gross motor dysfunction. Evidences regarding association of antenatal MgSO₄ with feed intolerance, NEC and SIP were from cohort studies and controversial.

CONCLUSIONS

We should continue use antenatal MgSO₄ to all eligible patients according to protocol till the more robust evidence will suggest association with gastrointestinal complications. In the meantime, we should have a high index of suspicion of gastrointestinal complications in extremely preterms particularly <26 weeks of gestation.

Respiratory severity score and extubation readiness in very low birth weight infants

BACKGROUND

The respiratory severity score (RSS) is a byproduct of mean airway pressure (MAP) and fraction of inspired oxygen (FiO₂). We sought to determine whether RSS could be used as a screening tool to predict extubation readiness in very low birth weight (VLBW) infants.

METHODS

In a retrospective cohort study, medical records of all VLBW infants admitted to our unit (6/1/09-2/28/12) were reviewed for infants' demographics, prenatal characteristics, and medication use. Also, records were reviewed for unplanned vs. planned extubation, blood gas, ventilator parameters and signs of severe respiratory failure [RF, defined as partial pressure of carbon dioxide (pCO₂) > 65, pH < 7.20, FiO₂ > 50%, and MAP > 10 cm] on the day of extubation.

RESULTS

During the study period 31% (45/147) failed extubation. Overall, infants who failed extubation had a lower birth weight (BW) and gestational age (GA), and on the day of extubation had a higher RSS and percentage of having one or more signs of severe RF. In a logistic regression model, adjusting for BW, GA, RSS and RF, RSS remained the only risk factor associated with extubation failure [adjusted OR 1.63 (95% CI: 1.10-2.40); p = 0.01]. RSS had a sensitivity of 0.86 (95% CI: 0.72-0.94) at a cutoff of 1.26 and a specificity of 0.88 (95% CI: 0.80-0.94) at a cutoff of 2.5. There was no difference in extubation failure between unplanned vs. planned extubation [41% (9/22) vs. 29% (36/125); p = 0.25].

CONCLUSION

An elevated RSS is associated with extubation failure. Successful unplanned extubation is common in VLBW infants.

Neonatal Effects of Maternal Magnesium Sulphate in Late Preterm and Term Pregnancies

Aim

To compare the clinical, obstetric and neonatal parameters between patients with > 34-week gestation having severe preeclampsia receiving magnesium sulphate and those with > 34-week gestation with preeclampsia but not receiving magnesium sulphate.

Materials and Methods

Single-centre prospective study studied 60 patients in each of the two groups. Magnesium sulphate was administered by Pritchard regimen as per standard protocol. Standard obstetric management was followed for both groups. In the severe preeclampsia/eclampsia group, maternal blood sample was analysed for serum magnesium levels. The duration of exposure, the amount of magnesium sulphate received and time elapsed between last dose of magnesium sulphate and delivery were all noted. Neonatal assessment was done. The various parameters including age, parity, blood pressure, mode of termination of pregnancy, NICU admission rate, incidence of hypotonia in the newborn and other neonatal parameters were tabulated and compared.

Results

The two groups were comparable with respect to age and parity. Need for induction of labour was higher in the group with severe preeclampsia/eclampsia. Rate of LSCS and birth weights were comparable between the two groups. NICU admission rate and incidence of hypotonia were higher in those who received magnesium sulphate. Amount of magnesium sulphate received and total duration of magnesium sulphate did not correlate with NICU admission rates.

Conclusions

Neonatal morbidity, in terms of higher NICU admission rates and hypotonia, is higher in patients receiving magnesium sulphate.

Effects of Maternal Magnesium Sulfate Treatment on Neonatal Feeding Tolerance

OBJECTIVE

To determine whether antenatal exposure to magnesium sulfate has an effect on neonatal enteral feeding tolerance.

METHODS

In this single-center, retrospective, observational study, charts of pregnant women who received intravenous magnesium sulfate infusions prior to delivery between July 1, 2012, and July 31, 2013, were reviewed. Neonates born at 24 weeks' gestational age or greater admitted to the neonatal intensive care unit (NICU) whose mothers received magnesium sulfate infusions prior to delivery were included. Neonates with independent factors that could lead to feeding intolerance were excluded. The primary outcome was incidence of neonatal enteral feeding intolerance measured by deviations from the NICU feeding protocol. Secondary outcomes included days on parenteral nutrition, incidence of necrotizing enterocolitis, time to first stool, and urine output in the first 72 hours of life.

RESULTS

Cumulative maternal magnesium sulfate dose was significantly higher in the enteral feeding intolerance group than those infants who tolerated enteral feeds (70.4 ± 52.3 vs 47.4 ± 40.1 g; p = 0.04). Infants exposed to more than 80 g of maternal magnesium sulfate therapy were more likely to develop enteral feeding intolerance (44% vs 22%; p = 0.04). Multivariate logistic regression indicated that prematurity and cumulative maternal magnesium sulfate dose were the strongest predictors of neonatal enteral feeding intolerance.

CONCLUSIONS

Infants of mothers who received more than 80 g of intravenous magnesium sulfate prior to delivery were more likely to develop feeding intolerance. Prematurity also was a significant predictor of intolerance.

[Need for resuscitation in preterm neonates less than 32 weeks treated with antenatal magnesium sulphate for neuroprotection]

INTRODUCTION

Magnesium sulphate administration is recommended for foetal neuroprotection in pregnant women at imminent risk of early preterm birth.

OBJECTIVE

To evaluate the relationship between intrapartum magnesium sulphate for foetal neuroprotection and delivery room resuscitation of preterm infants less 32 weeks.

PATIENTS AND METHOD

A prospective observational study was conducted on preterm infants less 32 weeks exposed to magnesium sulphate for neuroprotection, and a comparison made with another historic group immediately before starting this treatment. Cases in both groups that had not reached lung maturity with corticosteroids were rejected. The rates of resuscitation, morbidity and mortality for each of the groups were analysed and compared.

RESULTS

There was a total of 107 preterm, with 56 exposed to magnesium sulphate. Rate of advanced resuscitation were similar between the two groups. There were no other differences in mortality, invasive mechanical ventilation, time to first stool, and other comorbidities.

CONCLUSIONS

Intrapartum magnesium sulphate for foetal neuroprotection was not associated with an increased need for intensive delivery room resuscitation and other morbidities in these cohorts of less than 32 weeks preterm infants.

Alternative regimens of magnesium sulfate for treatment of preeclampsia and eclampsia: a systematic review of non-randomized studies

INTRODUCTION

The optimal dosing regimen of magnesium sulfate for treating preeclampsia and eclampsia is unclear. Evidence from the Cochrane review of randomized controlled trials (RCTs) was inconclusive due to lack of relevant data.

MATERIAL AND METHODS

To complement the evidence from the Cochrane review, we assessed available data from non-randomized studies on the comparative efficacy and safety of alternative magnesium sulfate regimens for the management of preeclampsia and eclampsia. Sources included Medline, EMBASE, Popline, CINAHL, Global Health Library, African Index Medicus, Biological abstract, BIOSIS and reference lists of eligible studies. We selected non-randomized study designs including quasi-RCTs, cohort, case-control and cross-sectional studies that compared magnesium sulfate regimens in women with preeclampsia or eclampsia.

RESULTS

Of 6178 citations identified, 248 were reviewed in full text and five studies of low to very low quality were included. Compared with standard regimens, lower-dose regimens appeared equally as good in terms of preventing seizures [odds ratio (OR) 1.02, 95% confidence interval (CI) 0.46-2.28, 899 women, four studies], maternal morbidity (OR 0.47, 95%CI 0.32-0.71, 796 women, three studies), and fetal and/or neonatal mortality (OR 0.87, 95%CI 0.38-2.00, 800 women, four studies). Comparison of loading dose only with maintenance dose regimens showed no differences in seizure rates (OR 0.99, 95%CI 0.22-4.50, 146 women, two studies), maternal morbidity (OR 0.53, 95%CI 0.15-1.93, 146 women, two studies), maternal mortality (OR 0.63, 95%CI 0.05-7.50, 146 women, two studies), and fetal and/or neonatal mortality (OR 0.49, 95%CI 0.23-1.03, 146 women, two studies).

CONCLUSION

Lower-dose and loading dose-only regimens could be as safe and efficacious as standard regimens; however, this evidence comes from low to very low quality studies and further high quality studies are needed.

Does magnesium exposure affect neonatal resuscitation?

OBJECTIVE

Research on immediate neonatal resuscitation suggests that maternal magnesium exposure may be associated with increased risk of low Apgar scores, hypotonia, and neonatal intensive care unit admission. However, not all studies support these associations. Our objective was to determine whether exposure to magnesium at the time of delivery affects initial neonatal resuscitation.

STUDY DESIGN

This is a secondary analysis of the Randomized Controlled Trial of Magnesium Sulfate for the Prevention of Cerebral Palsy that evaluated whether the study drug (magnesium or placebo) that was administered at the time of delivery was associated with increased risk for a composite adverse neonatal resuscitation outcome (5-minute Apgar score <7, oxygen administration in the delivery room, intubation, chest compressions, hypotension, and hypotonicity). A subgroup analysis was performed among patients who delivered at ≥30 weeks of gestation. Log-linear regression was used to control for possible confounders.

RESULTS

Data for 1047 patients were analyzed, of whom 461 neonates (44%) were exposed to magnesium. There was no increased risk for the primary composite outcome associated with magnesium exposure. Individual adverse neonatal outcomes and other secondary short-term neonatal outcomes that were evaluated also did not demonstrate an association with magnesium exposure.

CONCLUSION

Exposure to magnesium sulfate did not affect neonatal resuscitation or other short-term outcomes. These findings may be useful in planning neonatal care and patient counseling.

Magnesium sulfate exposure and neonatal intensive care unit admission at term

OBJECTIVE

The aim of this study was to investigate the effect of maternal magnesium sulfate (MgSO4) exposure for eclampsia prophylaxis on neonatal intensive care unit (NICU) admission rates for term newborns.

STUDY DESIGN

A secondary analysis of the Maternal-Fetal Medicine Unit Network Cesarean Registry, including primary and repeat cesarean deliveries, and failed and successful trials of labor after cesarean was conducted. Singleton pregnancies among women with preeclampsia and >37 weeks of gestation were included. Pregnancies with uterine rupture, chorioamnionitis and congenital malformations were excluded. Logistic regression analysis was used to determine associations between MgSO4 exposure and NICU admission. P<0.05 was considered statistically significant.

RESULT

Two thousand one hundred and sixty-six term pregnancies of women with preeclampsia were included, of whom 1747 (81%) received MgSO4 for eclampsia prophylaxis and 419 (19%) did not. NICU admission rates were higher among newborns exposed to MgSO4 vs unexposed (22% vs 12%, P<0.001). After controlling for neonatal birth weight, gestational age and maternal demographic and obstetric factors, NICU admission remained significantly associated with antenatal MgSO4 exposure (adjusted odds ratio 1.9, 95% confidence interval 1.3 to 2.6, P<0.001). Newborns exposed to MgSO4 were more likely to have Apgar scores <7 at 1 and 5 min (15% vs 11% unexposed, P=0.01 and 3% vs 0.7% unexposed, P=0.008). There were no significant differences in NICU length of stay (median 5 (range 2 to 91) vs 6 (3 to 15), P=0.5).

CONCLUSION

Antenatal maternal MgSO4 treatment was associated with increased NICU admission rates among exposed term newborns of mothers with preeclampsia. This study highlights the need for studies of maternal MgSO4 administration protocols that optimize maternal and fetal benefits and minimize risks.

Beneficence and Nonmaleficence in Treating Neonatal Hypoxic-Ischemic Brain Injury

The successful clinical translation of therapeutic hypothermia offers the tantalizing possibility that further improvements in outcomes may be possible by combining cooling with other neuroprotective drugs. The challenge now is to select from a daunting range of potential treatments. The patient's best interest must be central to ethical decision making at all times. However, the beneficence or nonmaleficence of potential therapies is seldom clear for any individual patient at the time of testing new therapies. Clinical randomized controlled trials are generally acknowledged by the scientific community as the 'gold standard' for evaluating interventions in health care. Therefore, ethical trial design is of the utmost importance. This paper explores contrasting ethical perspectives on how to select new interventions to treat neonatal encephalopathy after perinatal hypoxia-ischemia.

Magnesium for newborns with hypoxic-ischemic encephalopathy: a systematic review and meta-analysis

OBJECTIVE

Magnesium may have a role in neuroprotection in neonatal hypoxic-ischemic encephalopathy (HIE). The objective of this study was to systematically review the efficacy and safety of postnatal magnesium therapy in newborns with HIE.

STUDY DESIGN

MEDLINE, EMBASE, CINAHL and CCRCT were searched for studies of magnesium for HIE. Randomized controlled trials that compared magnesium to control in newborns with HIE were selected. The primary outcome was a composite outcome of death or moderate-to-severe neurodevelopmental disability at 18 months. When appropriate, meta-analyses were conducted using random effects model and risk ratios (RRs) and 95% confidence intervals (CIs) were calculated.

RESULT

Five studies with sufficient quality were included. There was no difference in the primary outcome between the magnesium and the control groups (RR 0.81, 95% CI 0.36 to 1.84). There was significant reduction in the unfavorable short-term composite outcome (RR 0.48, 95% CI 0.30 to 0.77) but no difference in mortality (RR 1.39, 95% CI 0.85 to 2.27), seizures (RR 0.84, 95% CI 0.59 to 1.19) or hypotension (RR 1.28, 95% CI 0.69 to 2.38) between the magnesium and the control groups.

CONCLUSION

The improvement in short-term outcomes without significant increase in side effects indicate the need for further trials to determine if there are long-term benefits of magnesium and to confirm its safety. Mortality was statistically insignificant between the magnesium and the control groups. However, the trend toward increase in mortality in the magnesium group is a major clinical concern and should be monitored closely in future trials.