Magnesium sulfate exposure and neonatal intensive care unit admission at term

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.

Term Neonatal Outcomes after Maternal Magnesium Sulfate Treatment for Seizure Prophylaxis

OBJECTIVE

 This study aimed to evaluate term neonatal outcomes after maternal magnesium sulfate (MgSO₄) treatment for seizure prophylaxis.

STUDY DESIGN

 This was a single-site retrospective cohort study of all women with term singleton gestation requiring MgSO₄ treatment for seizure prophylaxis and their respective neonatal outcomes from January 2013 through December 2020. Our primary outcome was neonatal intensive care unit (NICU) admission. We compared outcomes between women treated with MgSO₄ for 24 hours or more and women treated with MgSO₄ for less than 24 hours prior to delivery. Multivariable logistic regression was performed to calculate adjusted odds ratio (aOR) and 95% confidence interval (95% CI), controlling for variables with a p < 0.05 based on bivariable analysis.

RESULTS

 Of 834 women analyzed, 173 (20.7%) neonates were admitted to the NICU. Women treated with MgSO₄ for 24 hours or more compared with women treated with MgSO₄ for less than 24 hours were more likely to have neonates admitted to the NICU during their hospitalization (27.3 vs. 18.9%; p = 0.01), neonates requiring immediate NICU admission (24.6 vs. 18.3%; p < 0.01), and NICU admission for neonatal lethargy. After adjusting for covariates, only NICU admission due to neonatal lethargy remained statistically significant (aOR: 4.78 [95% CI: 1.50-15.21]).

CONCLUSION

 Prolonged MgSO₄ treatment for 24 hours or more was associated with increased odds of term NICU admission due to neonatal lethargy.

KEY POINTS

· NICU admission rose with longer magnesium treatment.. · Nulliparous patients had more magnesium sulfate exposure.. · Obese patients had longer magnesium sulfate exposure..

Neonatal magnesium levels are safe after maternal MgSO4 administration: a comparison between unexposed preterm neonates and neonates exposed for fetal neuroprotection or maternal eclampsia prevention-a cohort study

To objective of this study was to compare neonatal magnesemia in the first 15 days of neonatal life between three groups: a control group not exposed to MgSO₄, a neuroprotection group, and an eclampsia prevention group, and to explore its associations with child outcomes. A retrospective single-centre cohort study was performed in a tertiary care setting. Infants admitted at the neonatal intensive care unit born between 24 and 32 weeks' gestation, regardless of etiology of preterm birth, were included. The mean outcome measure was neonatal magnesemia (mmol/L). Linear mixed regression of neonatal magnesemia on exposure group and day of life was done. Generalised estimating equation models of child outcomes on neonatal magnesemia according to exposure group and day of life were made. The analyses showed that in neonatal magnesemia is significantly higher in the preeclampsia group compared to the control and neuroprotection groups. On the day of birth, this is irrespective of maternal magnesemia (preeclampsia vs control groups), and the maternal total dose or duration of MgSO₄ administration (preeclampsia vs neuroprotection group). No differences were found in short-term composite outcome between the three groups.

CONCLUSION

We found mean differences in neonatal magnesemia between children not exposed to MgSO₄ antenatally, children exposed for fetal neuroprotection, and children exposed for maternal eclampsia prevention. A 4-g loading and 1-g/h maintenance doses, for fetal neuroprotection and eclampsia prevention, appear to be safe on the short term for the neonate.

WHAT IS KNOWN

• Magnesium sulphate is a valuable medicine in obstetrics. The main indications are prevention of eclampsia and fetal neuroprotection. The most used dosage is a 4- or 6-g loading dose and a 1- or 2-g per h maintenance dose. It reduces neuromotor disabilities in extreme-to-moderate preterm born children.

WHAT IS NEW

• Maternal concentrations are supraphysiological and the maternal total dose can be high. Concentrations in neonates appear to remain in safe ranges. A dosage of 4-g loading and 1 g/h seems safe for the preterm neonate on the short term.

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.

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.

Neuroprotective effects of antenatal magnesium sulfate under inflammatory conditions in a Sprague-Dawley pregnant rat model

OBJECTIVE

Antenatal magnesium sulfate (MgSO₄) is recommended for fetal neuroprotection. The aim of this animal study was to assess the neuroprotective effect of in utero exposure to MgSO₄, under inflammatory conditions.

METHODS

Timed pregnant Sprague-Dawley (SD) rats (n = 29) received four intra-peritoneal (IP) injections of lipopolysaccharides (LPS; 200 μg/kg), combined with increasing concentrations of MgSO₄ (25, 50 or 100 mg/kg, n = 19) or saline solution (SS; n = 10). In the second set of experiments, animals (n = 8) received a single IP injection of i) LPS (500 μg/kg), MgSO₄ (50 mg/kg) and SS (n = 4) or ii) LPS (500 μg/kg), MgSO₄ (50 mg/kg) and IL-6 (12 μg/kg) (n = 4). Neurodevelopmental outcomes of surviving pups (n = 212) were assessed by the open field and the rotarod tests.

RESULTS

Pups' average weight at postnatal day (P) 25 was 75.77 g and 89.08 g in MgSO₄ and control groups, respectively (p = 0.02). Pups in MgSO₄ group have traveled a shorter distance and have shown reduced motor balance and coordination (p < 0.01). Average weight of pups receiving (LPS + MgSO₄+ IL-6) was 92.26 g at P25, compared to 75.86 g in (LPS + MgSO₄+SS) group (p < 0.05).

CONCLUSIONS

In our model, MgSO₄ induces pup's growth retardation and motor deficits, which may partly be related to a lower IL-6 circulating concentration.