Magnesium Sulfate Exposure Research Articles

Efficacy of antenatal magnesium sulfate in the prevention of necrotizing enterocolitis: A randomized case-control study in preterm neonates.

Objective: To assess the efficacy of administering antenatal magnesium sulfate in reducing the occurrence of necrotizing enterocolitis in preterm infants. Study Design: Randomized Case-control study. Setting: Hameed Latif Hospital Lahore. Period: August 2023- February 2024. Methods: The study including 80 preterm neonates (26 to 32 weeks gestation) was conducted at Neonatology & Gynaecology Unit Hameed Latif Hospital, Lahore. These neonates were divided into two groups: Group A included infants whose mothers were given magnesium sulfate before preterm birth, while Group B comprised of infants whose mothers did not receive magnesium sulfate. The primary outcome was the incidence of NEC in infants born to mothers exposed to magnesium sulfate, with secondary outcomes covering other neonatal morbidities and maternal side effects. Data analysis utilized SPSS Statistics software version 24, employing t-tests and multivariate logistic regression to evaluate the association between antenatal magnesium sulfate exposure and NEC incidence, considering a significant p-value of ≤ 0.05. Results: The overall NEC incidence was 5%(n=2). No NEC cases were reported in the control group. The difference in neonatal outcomes between both groups was statistically insignificant (p>0.05). Conclusion: Administering antenatal magnesium sulfate has no effect in decreasing the incidence of NEC in preterm infants.

Influence of recycled rubber and glass aggregates on magnesium sulfate resistance of geopolymers: Physio-mechanical properties and mechanisms

Recycled rubber aggregates (RRA) and recycled glass aggregates (RGA) are sustainable alternatives to natural aggregates. However, the influences of RRA and RGA on the magnesium sulfate resistance of geopolymers remain unclear. Previous studies have focused on the influences of binder type and composition on magnesium sulfate resistance but have neglected the role of aggregates. This study bridges this gap and demonstrates the influences of RRA and RGA on the magnesium sulfate resistance of geopolymers. This study investigated the physical properties, mechanical properties and phases of FA and GBFS-based geopolymers containing 0:10 – 10:0 RRA and RGA after being exposed to 5 % MgSO4 solution for 90 days. The results showed that compared to 100 % RGA, the 90-day length and mass of 100 % RRA increased by 50.48 and 33.22 times, respectively, and the 90-day compressive, flexural and splitting tensile strengths of 100 % RRA decreased by 65 %, 43.28 % and 56.75 %, respectively. However, the changes in length and mass of 100 % RGA were very small, and the mechanical properties even slightly increased rather than decreased. RRA + RGA showed an interval performance between 100 % RRA and 100 % RGA. The different magnesium sulfate resistance of RRA and RGA were attributed to the following mechanisms. RRA caused much higher drying shrinkage of geopolymers than RGA because the soft nature of RRA increased uncoordinated deformation, leading to micro-cracks in the matrix before magnesium sulfate exposure. The pre-existing micro-cracks served as physical transportation paths for external ions to diffuse into the interior of specimens, leading to expansive gypsum crystals formed in these micro-cracks. The accumulation of expansive gypsum crystals enlarged these micro-cracks and facilitated their propagation, leading to the expansion, cracking and degraded mechanical properties. By contrast, RGA reduced drying shrinkage due to its hard nature, which limited the availability of micro-cracks as physical transportation paths for external ions and therefore reduced the formation of expansive gypsum crystals and improved the magnesium sulfate resistance of geopolymers.

Short-term improvement of ductile geopolymer composites exposed to magnesium sulfate: Mechanical properties, sorptivity, and mechanisms

Geopolymers are eco-friendly substitutions for cement whose manufacture causes high carbon emissions and energy consumption. Drying shrinkage and brittleness are common defects for geopolymers, and polyvinyl alcohol (PVA) fibers can be employed to suppress these defects. Thus, ductile geopolymer composites (DGC) are preferred. Magnesium sulfate attack is one of the durability concerns over the geopolymers employed for construction. However, previous studies focused on long-term exposure behaviors, and the knowledge of short-term exposure influences and mechanisms is limited. To clarify the gaps, the current research investigated the physical properties, mechanical properties, sorptivity, phases, and microstructure of DGC incorporating 0–0.6% vol.% PVA fibers, and the DGC was exposed to 5% magnesium sulfate solution for 0, 30, 60, and 90 d. According to the results, the short-term exposure increased DGC's compressive, flexural, and splitting tensile strengths by 5.25%–8.33%, 12.02%–17.17%, and 19.31%–27.93%, respectively, as well as sorptivity by 55.15%–64.48%. Short-term magnesium sulfate exposure improved mechanical properties and sorptivity, contrary to performance deterioration caused by long-term exposure. Mechanisms for the improvement are as follows: (a) sodium-calcium-magnesium sulfo-aluminosilicate (SCMSAS) crystals were formed in micropores, which reduced DGC's porosity. The decreased porosity enhanced mechanical properties and reduced sorptivity; (b) no large amounts of expansive gypsum and ettringite crystals were detected after short-term exposure, and their substantial formations were the causes of long-term exposure deterioration; (c) aluminosilicate polymer structures were improved owing to increased stability and mean chain length, which helped enhance DGC's mechanical properties.

Long-term effects of prenatal magnesium sulfate exposure on nervous system development in preterm-born children.

This study used structural magnetic resonance imaging to analyze changes in the gray matter volume (GMV) of preterm-born (PTB) and term-born (TB) children to help elucidate the influence of magnesium sulfate treatment on the nervous system development. A total of 51 subjects were recruited, including 28 PTB and 23 TB children. The intelligence scale and MRI scan were completed at the corrected age of 10 to 16 years. A whole-brain voxel-wise analysis tested the main effect of the status (PTB without magnesium, PTB with magnesium, and TB) using a factorial design in SPM8. The mean volumes of the regions that showed significant group effects on the GMV after the FDR correction were extracted in the common space for each subject. Verbal and full-scale intelligence quotient scores were significantly lower for PTB children without magnesium than for TB children; however, the scores of PTB children with magnesium and TB children were almost identical. Compared with TB children, PTB children had significantly reduced left straight gyrus and left inferior frontal gyrus GMVs; however, the volumes of PTB children with magnesium were closer to those of TB children. Changes in the GMV of the left inferior frontal gyrus were significantly correlated with full-scale and verbal intelligence quotient scores, whereas the lower gestational age at the time of mgsou4 treatment led to a larger GMV of the left inferior frontal gyrus. Brain structural abnormalities could exist in PTB children. The GMVs of the left straight gyrus and left inferior frontal gyrus were significantly reduced in these children. The influence of magnesium sulfate treatment was not significant, but the cognitive levels of these children were significantly increased and almost identical to those of TB children. Initiation of magnesium sulfate treatment during gestation is negatively correlated with the left inferior frontal gyrus GMV.

Correlation between magnesium sulphate exposure in utero and serum calcium and alkaline phosphatase levels in preterm infants

Magnesium sulphate (MgSO4) is administered to pregnant women at risk of preterm labour and eclampsia. Since prolonged exposure to antenatal MgSO4 is considered to be a risk factor for infant skeletal demineralization, we evaluated infants exposed to antenatal MgSO4 for bone and mineral metabolism using their umbilical cord blood. The study population comprised 137 preterm infants. Forty-three infants were exposed (exposure group) and 94 infants were not exposed (control group) to antenatal MgSO4. Blood samples from the umbilical cords and infants were analysed with respect to mineral metabolism, intact parathyroid hormone (iPTH) level, and alkaline phosphatase (ALP) level. Correlation between the level of these parameters and the duration and dosage of MgSO4 was also examined. Preterm infants in the exposure group were antenatally exposed to MgSO4 for a median (IQR) period of 14 (5-34) days and a dosage of 447 (138-1118) g. Serum calcium levels were lower (8.8 vs 9.4 mg/dL, p<0.001) and ALP levels were higher (312 vs 196 U/L, p<0.001) in the exposure group. Serum calcium levels did not correlate with MgSO4 administration dosage and therapy duration, however, ALP levels correlated with the duration and total dosage of MgSO4 (Spearman's rank correlation r [95% confidence interval]: 0.55 [0.30-0.73], p <0.001 and 0.63 [0.40-0.78], p <0.001, respectively). Prolonged periods and higher doses of antenatal MgSO4 exposure can cause in utero abnormal bone metabolism in preterm infants.

Resistance of carbonation-cured belite-rich cement mortar to adverse environments: Magnesium sulfate and sulfuric acid exposure

The present study investigates the potential of carbonation-cured belite-rich cement (BRC) to resist magnesium sulfate (MgSO4) and sulfuric acid (H2SO4) environments. BRC mortar was submerged in 5% and 10% MgSO4 and H2SO4 solutions. The gains of the compressive strength and mass under MgSO4 environment significantly depend upon the buffer (unreacted belite phase) left in the specimen after 28 days of curing. The lowest buffer level, found after 28 days of carbonation curing, stemmed from the higher reactivity of the belite phase as opposed to water curing followed by carbonation curing. Furthermore, degradations in the strength and mass were found in the H2SO4 environment. The presence of the calcium carbonate phase in carbonation-cured BRC mortar increased the acid resistance. An XRD analysis showed sulfate-based mineral phases in the external and core areas of a carbonation-cured BRC mortar cube, representing the higher diffusion efficiency of acid ions than magnesium ions in BRC.

Intrapartum magnesium sulfate exposure and obstetric hemorrhage risk

Background The gold standard intrapartum treatment for preeclampsia with severe features is magnesium sulfate in order to provide prophylaxis against eclampsia. However, though magnesium sulfate is known to have a relaxant effect on uterine muscle, there have been variable reports in the literature in regard to the association between magnesium and obstetric hemorrhage (OBH). Objective We aim to compare OBH incidence in patients with hypertensive disease of pregnancy (HDP) with or without exposure to intrapartum magnesium sulfate. Methods We performed a retrospective cohort study of all deliveries at our institution associated with a diagnosis of hypertensive disease of pregnancy (HDP) (e.g. chronic and gestational hypertension, preeclampsia with or without severe features, eclampsia, or HELLP) from January 1, 2018 to December 31, 2019. The category of HDP diagnosis was determined by a detailed chart review by trained chart abstractors. The primary outcome was total quantitative blood loss (QBL) and the rate of obstetric hemorrhage. Secondary outcomes included a composite of obstetric hemorrhage-related maternal morbidity outcomes (OBH-M), the individual composite components and the incidence of additional hemorrhage-related interventions (e.g. uterotonics and surgical interventions). We also examined the same primary and secondary outcomes in a stratified analysis based on delivery mode (i.e. vaginal deliveries only and cesarean deliveries only). Results Of 791 patients with a diagnosis of HDP, 411 patients received magnesium sulfate for eclampsia prophylaxis and 380 patients did not receive magnesium sulfate. For all delivery modes, there was a significantly higher QBL (p < .01), increased rate of OBH (p = .04) and increased OBH-M (p < .01) in deliveries associated with intrapartum exposure to magnesium compared to those without. However, our stratified analysis by delivery mode demonstrated that magnesium-related hemorrhage risk only persisted for vaginal deliveries (QBL p < .01; OBH aOR 1.47, 95% CI: 0.75–2.85; OBH-M aOR 1.47, 95% CI 1.00–7.55) with no significant hemorrhage-related differences among cesareans with or without magnesium exposure (QBL p = .51; OBH aOR 1.45, 95% CI: 0.85–2.47; OBH-M 1.50 95% CI: 0.70–3.23). Conclusion Intrapartum exposure to magnesium sulfate use was associated with an increase in QBL and risk of OBH-M in vaginal deliveries, but not associated with any hemorrhage-related outcome differences in cesarean deliveries. More research is needed to explore the effects of hypertensive disease, magnesium exposure, and delivery mode on obstetric hemorrhage risk.

Retraction and republication - effect of antenatal magnesium sulphate on MRI biomarkers of white matter development at term equivalent age: The MagNUM Study.

On August 25, 2020, eBioMedicine published online findings from a nested cohort study within the randomised Magnesium sulphate at 30 to <34 weeks’ Gestational age Neuroprotection Trial (MAGENTA). On November 17, 2021, the authors drew our attention to an error that was discovered when the dataset for the parent randomised trial was being finalised. The original MagNUM analysis was conducted blind to treatment group allocation, and an incorrect code was used at the end of that analysis to identify the magnesium sulphate and placebo study groups. Therefore, the group allocations to the magnesium sulphate and placebo study groups in the paper were inadvertently reversed, making the findings, as reported, unreliable. eBioMedicine editors discussed the corrections that were needed in the paper and decided, in accordance with the Committee on Publication Ethics’ guidelines, that because of the extent of the changes necessary, the previous version of the Article should be retracted. As these data are still worthy of publication, a corrected version will be republished after reanalysis and rereview. Today we retract the previous version and republish online the corrected version of the article DOI: 10.1016/j.ebiom.2022.103923 in which the results are unchanged apart from the treatment group assignment. The figures and tables have been corrected accordingly, and the overall message has been modified to convey that antenatal magnesium sulphate prior to preterm birth after 30 weeks’ gestation does not promote white matter development in pathways affecting motor and cognitive function. The previous version of the Article has been added to the appendix in the new version and is marked retracted. The Editors of eBioMedicine. None. RETRACTED: Effect of antenatal magnesium sulphate on MRI biomarkers of white matter development at term equivalent age: The magnum studyThis article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). Full-Text PDF Open AccessEffect of antenatal magnesium sulphate on MRI biomarkers of white matter development at term equivalent age: The MagNUM StudyIn babies born preterm after 30 weeks’ gestation, antenatal magnesium sulphate exposure did not promote development of white matter microstructure in pathways affecting motor or cognitive function. This suggests that if the neuroprotective effect of magnesium sulphate treatment prior to preterm birth is confirmed at this gestation, the mechanisms are not related to accelerated white matter maturation inferred from fractional anisotropy. Full-Text PDF Open Access

Effect of antenatal magnesium sulphate on MRI biomarkers of white matter development at term equivalent age: The MagNUM Study.

SummaryBackgroundMagnesium sulphate given to women prior to very preterm birth protects the perinatal brain, so fewer babies die or develop cerebral palsy. How magnesium sulphate exerts these beneficial effects remains uncertain. The MagNUM Study aimed to assess the effect of exposure to antenatal magnesium sulphate on MRI measures of brain white matter microstructure at term equivalent age.MethodsNested cohort study within the Magnesium sulphate at 30 to <34 weeks’ Gestational age Neuroprotection Trial (MAGENTA). Australian New Zealand Clinical Trials Registry ACTRN12611000491965. Mothers at risk of preterm birth at 30 to <34 weeks’ gestation were randomised to receive either 4 g of magnesium sulphate heptahydrate [8 mmol magnesium ions], or saline placebo, when preterm birth was planned or expected within 24 h. Participating babies underwent diffusion tensor MRI at term equivalent age. The main outcomes were fractional anisotropy across the white matter tract skeleton compared using Tract-based Spatial Statistics (TBSS), with adjustment for postmenstrual age at birth and at MRI, and MRI site. Researchers and families were blind to treatment group allocation during data collection and analyses.FindingsOf the 109 babies the demographics of the 49 babies exposed to magnesium sulphate were similar to the 60 babies exposed to placebo. In babies whose mothers were allocated to magnesium sulphate, fractional anisotropy was lower within the corticospinal tracts and corona radiata, the superior and inferior longitudinal fasciculi, and the inferior fronto-occipital fasciculi compared to babies whose mothers were allocated placebo (P < 0·05).InterpretationIn babies born preterm after 30 weeks’ gestation, antenatal magnesium sulphate exposure did not promote development of white matter microstructure in pathways affecting motor or cognitive function. This suggests that if the neuroprotective effect of magnesium sulphate treatment prior to preterm birth is confirmed at this gestation, the mechanisms are not related to accelerated white matter maturation inferred from fractional anisotropy.FundingThis study was funded by a project grant from the Health Research Council of New Zealand (HRC 14/153).

Changing Tocolytic Exposures among Neonatal Intensive Care Unit Admitted Preterm Infants.

Since 2010, the American College of Obstetrics and Gynecology have released three committee opinions to recommend and reaffirm the utility of magnesium sulfate for neuroprotection and later for tocolysis to achieve antenatal steroid course completion in preterm labor. We sought to determine changes in antenatal magnesium sulfate exposure and other tocolytic agents for pregnancies resulting in neonatal intensive care unit (NICU)-admitted preterm infants. Using the Pediatrix Clinical Data Warehouse, we evaluated all inborn infants delivered between 22 and 33 weeks' gestation and admitted to the intensive care units from 2009 to 2018. We classified patients based on antenatal exposure to tocolytic medications: calcium channel blockers (nifedipine and amlodipine), betamimetics (terbutaline, theophylline, and ritodrine), prostaglandin inhibitors (indomethacin), and magnesium sulfate. A total of 229,781 patients met inclusion criteria. During the study period, magnesium sulfate exposure increased from 27.6 to 57.7% of births while betamimetic exposure decreased from 10.2 to 5.2%. Increasing magnesium sulfate exposure over time was seen at all gestational ages examined and magnesium exposure was most common between 23 and 31 weeks' gestation. By 2017 to 2018, 70.5% of 24 to 29 weeks' gestation NICU infants received exposure to at least one tocolytic agent while this remained at 53.7% of 32 to 33 weeks' NICU admitted infants. Antenatal steroid exposure increased from 74.8 to 87.4% during the study period. For NICU-admitted preterm infants, prenatal exposure patterns to tocolytic agents has shifted since 2009 with prenatal magnesium sulfate exposure increasing significantly. Antenatal steroid exposure has risen concurrently. Exposure to tocolytic agents is the highest among preterm infants born between 24 and 29 weeks' gestation. · Exposure to magnesium sulfate significantly increased from 2009 to 2018 for NICU admitted infants.. · Concurrently, the use of other tocolytics decreased significantly.. · The use of antenatal steroids has been rising over time..

Fly ash geopolymer concrete durability to sulphate, acid and peat attack

The durability of concrete has a profound impact on the service life of structural elements. Indonesia has extensive peat soils, which provide a highly aggressive environment for concrete structures. Geopolymer concrete has demonstrated good durability when exposed to acid /sulphate conditions similar to those encountered in peat soils. This paper investigates the performance of geopolymer concretes produced using Indonesian type F fly ash under sulphate and acid chemical attack. Geopolymer concrete specimens have been exposed for 12-months in a range of solutions: 5% sodium sulphate, 5% magnesium sulphate, 1% and 3% sulphuric acid, and simulated peat solution. The mechanical and durability properties of specimens together with a control concrete have been monitored for compressive strength, change in mass, water absorption and volume of permeable voids, ultra pulse velocity, air and water permeability, pH profile, and microstructural analysis (XRD, SEM/EDS). The control immersed in water achieved 56.93 MPa at 12-months of age. Magnesium sulphate exposure had a significant deterioration impact on the compressive strength of geopolymer concrete, demonstrating an 11% reduction in strength, while those exposed to sodium sulphate had an 8.9% increase in strength. Specimens exposed to peat solution displayed a slightly increased strength and those in acid conditions a 1.2% and 4.5% decrease in 1% acid and 3% acid, respectively. In general, the geopolymer concrete displayed a high level of resistance against sodium sulphate, 1% sulphuric acid and simulated peat attack.

Producing Heavyweight High-Performance Concrete by Using Black Sand as Newly Shielding Construction Material

Experimental work was carried out to study new fine aggregate shielding construction materials, namely black sand (BS). The BS effect on the mechanical, durability, and shielding characteristics of heavyweight high-performance concrete (HWHPC) was evaluated. This study aimed at improving various HWHPC properties, concertedly. Fifteen mixtures of HWHPC were made, with various variables, including replacing 10% and 15% of the cement with fly ash (FA) and replacing normal sand by BS at various contents (15%, 30%, 45%, 60%, 75%, and 100%). The test specimens were subjected to various exposure conditions, including elevated temperatures, which ranged from 250 °C to 750 °C, for a duration of 3 h; magnesium sulfate (MS) exposure; and gamma-ray exposure. The effects of elevated temperature and sulfate resistance on concrete mass loss were examined. The results revealed that BS is a promising shielding construction material. The BS content is the most important factor influencing concrete compressive strength. Mixes containing 15% BS demonstrated significantly better strength compared to the control mixes. Exposure to 250 °C led to a notable increase in compressive strength. BS showed a significant effect on HWHPC fire resistance properties, especially at 750 °C and a significant linear attenuation coefficient. Using 10% FA with 15% BS was the most effective mixing proportion for improving all HWHPC properties concertedly, especially at greater ages.

Does antenatal magnesium sulphate improve hearing function in premature newborns?

Objective:To evaluate whether antenatal magnesium sulphate (MgSO4) exposure has a neuroprotective effect against hearing impairment in premature newborns.Material and Methods:Retrospective cohort study was performed with prematurely (<37 weeks) delivered newborns at a tertiary university hospital. Newborns of 92 women who received MgSO4 infusions (study group) for various indications were compared to newborns of 147 women who did not receive MgSO4 infusions (control group). All eligible premature newborn underwent hearing screening by auditory brainstem response (ABR) testing before being discharged from the hospital.Results:The fail rate for ABR hearing screening was 3.3% (n=3) in the study group and 10.9% (n=16) in the control group (p=0.034). The rate of concurrent use of betamethasone was higher in the study group (72.8%; n=67) compared to control group (29.2%; n=43) (p<0.001). Other neonatal parameters, such as the number of neonates who were small for gestational age and the rate of microcephaly were similar between the groups (p=0.54, p=0.48, respectively). After adjusting for co-variates including the use of betamethasone and gestational age at delivery, no statistically significant association between antenatal administration of MgSO4 and ABR fail rates were found (p=0.07).Conclusion:These results do not suggest a significant benefit in terms of hearing impairment in premature newborns when antenatal MgSO4 infusion was given.

Effect of antenatal magnesium sulphate on MRI biomarkers of white matter development at term equivalent age: The magnum study.

BackgroundMagnesium sulphate given to women immediately prior to very preterm birth protects the perinatal brain, so fewer babies die or develop cerebral palsy. How magnesium sulphate exerts these beneficial effects remains uncertain. The aim of the MagNUM Study was to assess the effect of exposure to antenatal magnesium sulphate on MRI measures of brain white matter microstructure at term equivalent age.MethodsNested cohort study within the randomised Magnesium sulphate at 30 to <34 weeks’ Gestational age Neuroprotection Trial (MAGENTA). Mothers at risk of preterm birth at 30 to <34 weeks’ gestation were randomised to receive either 4 g of magnesium sulphate heptahydrate [8 mmol magnesium ions], or saline placebo, infused over 30 min when preterm birth was planned or expected within 24 h. Participating babies underwent diffusion tensor MRI at term equivalent age. The main outcomes were fractional anisotropy across the white matter tract skeleton compared using Tract-based Spatial Statistics (TBSS), with adjustment for postmenstrual age at birth and at MRI, and MRI site. Researchers and families were blind to treatment group allocation during data collection and analyses.FindingsOf the 109 participating babies the demographics of the 60 babies exposed to magnesium sulphate were similar to the 49 babies exposed to placebo. In babies whose mothers were allocated to magnesium sulphate, fractional anisotropy was higher within the corticospinal tracts and corona radiata, the superior and inferior longitudinal fasciculi, and the inferior fronto-occipital fasciculi compared to babies whose mothers were allocated placebo (P < 0.05).InterpretationIn babies born preterm, antenatal magnesium sulphate exposure promotes development of white matter microstructure in pathways affecting both motor and cognitive function. This may be one mechanism for the neuroprotective effect of magnesium sulphate treatment prior to preterm birth.FundingHealth Research Council of New Zealand.

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

BackgroundThere 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 findingsCINAHL, 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.ConclusionsOur 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.

Changes on preterm morbidities with antenatal magnesium

Purpose: The effect of magnesium sulphate (MgSO4) to mothers with imminent premature birth at &amp;lt;34 weeks on neonatal morbidities like intraventricular hemorrhage, feeding intolerance, retinopathy or bronchopulmoner dysplasia is not clear. We evaluated the effect of antenatal magnesium sulfate exposure on premature early and late morbidities and mortality retrospectively.Materials and Methods: 108 infants ≤ 32 gestational age having antenatal magnesium were grouped as Mg (+) and 172 infants ≤ 32 gestational age not having antenatal magnesium were grouped as Mg (-).Results: Respiratory Distress Syndrome, intraventricular hemorrhage, severe intraventricular hemorrhage (grade 3 and 4), retinopathy of prematurity and bronchopulmonary dysplasia were less in Mg (+) group compared to Mg (-) group but it is not statistically significant, except Respiratory Distress Syndrome.Conclusion: This retrospective study showed that ante natal exposure to MgSO4 did not have statistically significant beneficial effect on either morbidities or mortality in premature infants.

Does Introduction of Normal Saline Tip the Electrolyte Balance in Preeclampsia? [33I

INTRODUCTION: Due to a nationwide shortage of Ringer's lactate, normal saline became the intravenous fluid of choice at our institution in 5/2018. Recent studies have raised concern on safety of administration of normal saline in critically ill patients. We sought to evaluate the impact of normal saline on the outcomes of women with preeclampsia receiving magnesium sulfate. METHODS: Prospective observational study of women with preeclampsia with severe features receiving normal saline. The amount of normal saline administered was calculated and a basic metabolic panel was surveyed approximately 12 hours after initiation of magnesium sulfate prophylaxis. Laboratory analytes were examined according to the amount of intravenous fluid received. RESULTS: From 5/2018 to 7/2018, a total of 124 patients were identified. The mean intravenous fluid volume received was 1.84 ± 0.9 L. Serum creatinine and chloride levels remained unchanged over time and across quartiles of amount of fluid received (p=0.322 and p=0.822, respectively). Incidentally, a significant relationship was found between calcium levels and both the amount of normal saline received (p=0.0003) and concurrent magnesium levels (p<.0001). When testing for interaction between calcium, magnesium, and normal saline, both of the latter contributed to an increased risk of hypocalcemia. CONCLUSION: There does not appear to be a significant consequence to either chloride levels or renal function when utilizing normal saline in women with preeclampsia receiving magnesium sulfate. Coincidentally, calcium levels significantly declined as the amount of intravenous fluid increased, which given the association with magnesium levels is suspected to be a function of magnesium sulfate exposure.

Does Introduction of Normal Saline Tip the Electrolyte Balance in Preeclampsia? [33I

INTRODUCTION: Due to a nationwide shortage of Ringer's lactate, normal saline became the intravenous fluid of choice at our institution in 5/2018. Recent studies have raised concern on safety of administration of normal saline in critically ill patients. We sought to evaluate the impact of normal saline on the outcomes of women with preeclampsia receiving magnesium sulfate. METHODS: Prospective observational study of women with preeclampsia with severe features receiving normal saline. The amount of normal saline administered was calculated and a basic metabolic panel was surveyed approximately 12 hours after initiation of magnesium sulfate prophylaxis. Laboratory analytes were examined according to the amount of intravenous fluid received. RESULTS: From 5/2018 to 7/2018, a total of 124 patients were identified. The mean intravenous fluid volume received was 1.84 ± 0.9 L. Serum creatinine and chloride levels remained unchanged over time and across quartiles of amount of fluid received (p=0.322 and p=0.822, respectively). Incidentally, a significant relationship was found between calcium levels and both the amount of normal saline received (p=0.0003) and concurrent magnesium levels (p<.0001). When testing for interaction between calcium, magnesium, and normal saline, both of the latter contributed to an increased risk of hypocalcemia. CONCLUSION: There does not appear to be a significant consequence to either chloride levels or renal function when utilizing normal saline in women with preeclampsia receiving magnesium sulfate. Coincidentally, calcium levels significantly declined as the amount of intravenous fluid increased, which given the association with magnesium levels is suspected to be a function of magnesium sulfate exposure.

Lack of Evidence for Time or Dose Relationship between Antenatal Magnesium Sulfate and Intestinal Injury in Extremely Preterm Neonates

Background: Recent studies reported conflicting results on the relationship between antenatal magnesium sulfate (MgSO₄) exposure and neonatal intestinal injury. Most studies have not assessed MgSO₄ exposure quantitatively and none reported the exposure timing. Objectives: The aim of this work was to assess whether there is a temporal or dose-dependent relationship between antenatal MgSO₄ exposure and intestinal injury in extremely preterm neonates. Methods: A retrospective study was made of inborn neonates with gestational age ≤28 weeks and/or birth weights ≤1,000 g. Primary outcomes included necrotizing enterocolitis (NEC), spontaneous intestinal perforation (SIP), and/or death prior to discharge or in the first 2 weeks of life. Outcome comparisons were made based on the timing of MgSO₄ exposure, within 7 days (Mg7D) or within 3 days (Mg3D) of birth. Total cumulative doses for the Mg3D group were also computed. Results: A total of 302 neonates were included, 210 in the Mg7D group, out of whom 179 (85.2%) constituted the Mg3D group. There were no differences noted when comparing MgSO₄ exposure timing and the likelihood of NEC, SIP, and/or death. This remained the same for subgroup analysis of neonates < 26 weeks’ gestation. Each 10-g increase in MgSO₄ cumulative dose correlated with a decrease in SIP/NEC/death by 18.9% prior to discharge and by 21.9% in the first 2 weeks of life. Small for gestational age (SGA) was a potential effect modifier by a likelihood ratio test with p = 0.07. Conclusions: Antenatal MgSO₄ exposure in extremely preterm neonates was not associated with an increased risk of intestinal injury or death, and might have reduced these complications in a dose-dependent manner in our study. This protective effect was more noticeable in SGA neonates.

489: Does antenatal magnesium sulfate exposure increase the risk of necrotizing enterocolitis in preterm neonates?

489: Does antenatal magnesium sulfate exposure increase the risk of necrotizing enterocolitis in preterm neonates?