The role of calcium, magnesium, and zinc in pre-eclampsia

Genetically predicted circulating concentrations of micronutrients and risk of hypertensive disorders of pregnancy: a Mendelian randomization study

PURPOSE

Epidemiological studies examining the association between circulating micronutrients and the risk of hypertensive disorders during pregnancy (HDP) have produced inconsistent results. Therefore, we conducted a Mendelian randomization (MR) analysis to evaluate the potential causal relationship between micronutrients and HDP.

METHODS

Nine micronutrients (beta-carotene, vitamin B6, vitamin B12, calcium, zinc, selenium, copper, folate, and phosphorus) were selected as the exposure factors. Summary data for gestational hypertension (14,727 cases and 196,143 controls) and preeclampsia/eclampsia (7212 cases and 174,266 controls) were extracted from the FinnGen consortium. The MR analysis employed the inverse variance weighted method and conducted a range of sensitivity analyses.

RESULTS

The inverse variance weighted method indicated no significant causal relationship between nine genetically predicted micronutrient concentrations and gestational hypertension, as well as preeclampsia/eclampsia. Sensitivity analyses suggested the absence of pleiotropy.

CONCLUSION

There is no strong evidence to support the causation between circulating micronutrients and hypertensive disorder during pregnancy.

An association of deficiencies in balanced dietary practices and inadequate iron and folic acid supplement's intake during pregnancy and increasing risk of pre-eclampsia or eclampsia among Indian women

Pre-eclampsia or eclampsia is a serious reproductive health problem which can cause maternal, fetal and neonatal morbidity and mortality worldwide. However till the notable reasons of it is not very clear at all. The main essence of the present study was to examine the association between dietary intake, iron and folic acid consumption during pregnancy and the chances of occurrences of pre-eclampsia or eclampsia among Indian women. A cross sectional observational study was performed by using NFHS-5 (2019-21) data. 190,797 ever married women aged between 15-49 years who had a live birth in the past five years preceding the survey were availed for this study. Multivariable logistic regression analysis was carried out to find out the association between dietary and supplementary intake and occurrences of eclampsia. About 3.6% of the sample women had pre-eclampsia or eclampsia. The results of the study indicated that the likelihood of the prevalence of pre-eclampsia or eclampsia was significantly higher among those women who did not take adequate diet and as well as not consumed iron and folic acid tablet or syrup for at least 90 days during pregnancy compared to those women who took adequate diet and iron and folic acid supplementation even after controlling some maternal, health and lifestyle, socio-economic and demographic characteristics. Integrated and quality ANC services can only ensure adequate nutritional intake in terms of healthy and balanced diet. So, quality ANC services and with this micronutrients intake could be an effective way to reduce the prevalence of pre-eclampsia or eclampsia.

Oxidative Stress in Pregnancy

Recent years have seen an increased interest in the role of oxidative stress (OS) in pregnancy. Pregnancy inherently heightens susceptibility to OS, a condition fueled by a systemic inflammatory response that culminates in an elevated presence of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in the circulatory system. The amplified OS in pregnancy can trigger a series of detrimental outcomes such as underdevelopment, abnormal placental function, and a host of pregnancy complications, including pre-eclampsia, embryonic resorption, recurrent pregnancy loss, fetal developmental anomalies, intrauterine growth restriction, and, in extreme instances, fetal death. The body's response to mitigate the uncontrolled increase in RNS/ROS levels requires trace elements that take part in non-enzymatic and enzymatic defense processes, namely, copper (Cu), zinc (Zn), manganese (Mn), and selenium (Se). Determination of ROS concentrations poses a challenge due to their short half-lives, prompting the use of marker proteins, including malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), catalase (CAT), and glutathione (GSH). These markers, indicative of oxidative stress intensity, can offer indirect assessments of pregnancy complications. Given the limitations of conducting experimental studies on pregnant women, animal models serve as valuable substitutes for in-depth research. This review of such models delves into the mechanism of OS in pregnancy and underscores the pivotal role of OS markers in their evaluation.

Maternal antioxidant micronutrient deficiencies among pre-eclamptic women in Enugu, Nigeria: a cross-sectional analytical study

OBJECTIVES

To determine the prevalence of antioxidant micronutrient deficiencies in pregnant women with pre-eclampsia and healthy pregnant women, and to assess the relationships between trace element deficiency in pregnancy and the severity of pre-eclampsia in Enugu, Nigeria.

METHODS

We performed a secondary analysis of a cross-sectional analytical study of serum concentrations of copper, selenium, zinc, magnesium, and manganese in 81 pregnant women with pre-eclampsia and healthy pregnant women (controls) who were matched for age, gestational age, body mass index, and parity. This study was performed at the University of Nigeria Teaching Hospital, Ituku-Ozalla, Enugu. Participants' sera were analyzed with an atomic absorption spectrophotometer.

RESULTS

Trace element deficiencies were common and similar between women with pre-eclampsia and controls. However, women with pre-eclampsia were more likely to be deficient in manganese than controls (odds ratio = 2.28, 95% confidence interval: 1.90-2.75). Among the micronutrients studied, only manganese concentrations were significantly lower in women without severe symptoms of pre-eclampsia than in those with severe symptoms of pre-eclampsia.

CONCLUSIONS

Micronutrient deficiency is common in pregnant women with pre-eclampsia and in healthy pregnant women in Enugu, Nigeria. Only manganese deficiency is higher in women with pre-eclampsia than in healthy pregnant women.

The association between dietary mineral intake and the risk of preeclampsia in Chinese pregnant women: a matched case-control study

Previous studies on the relationship between dietary minerals and preeclampsia (PE) have given inconsistent results. The aim of this study was to further clarify the relationship between dietary minerals intake and PE in Chinese pregnant women. In this study, 440 pairs of hospital-based preeclamptic and healthy women were matched 1:1. Dietary intake was obtained through a 78-item semi-quantitative food frequency questionnaire. Multivariate conditional logistic regression was used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs). Restricted cubic splines were plotted to evaluate the dose-response relationship between dietary minerals intake and PE. This study found significant inverse associations for dietary intake of calcium, magnesium, phosphorus, iron, copper, manganese and zinc and the risk of PE in both univariate and multivariate models (all P- trend < 0.05). After adjusting for possible confounders, compared with the lowest quartile, the odds ratio of the highest quartile was 0.74 (95% CI 0.56-0.98) for calcium, 0.63 (95% CI 0.42-0.93) for magnesium, 0.45 (95% CI 0.31-0.65) for phosphorus, 0.44 (95% CI 0.30-0.65) for iron, 0.72 (95% CI 0.53-0.97) for copper, 0.66 (95% CI 0.48-0.91) for manganese and 0.38 (95% CI 0.25-0.57) for zinc. In addition, a reverse J-shaped relationship between dietary minerals intake and PE risk was observed (P-overall association < 0.05). In Chinese pregnant women, a higher intake of dietary minerals, including calcium, magnesium, phosphorus, copper, iron, manganese, and zinc was associated with a lower odds of PE.

Are Twin Pregnancies at Higher Risk for Iron and Calcium Deficiency than Singleton Pregnancies?

The aim of this study was to compare the iron and calcium status in singleton and twin pregnancies and to assess whether there is an increased risk for iron and calcium deficiency in twin gestation. The study included 105 singleton and 9 twin pregnancies at or above 35 weeks of gestation. Information on prenatal supplementation with iron or calcium was acquired, and adverse perinatal outcomes were recorded. Biosamples from all 114 mothers and 73 newborns (61 singleton and 12 twin newborns) were finally analyzed. Total iron and calcium concentrations in serum were measured through total reflection X-ray fluorescence analysis. The results indicated no significant differences in maternal serum iron and calcium concentrations between singleton and twin pregnancies. Similarly, iron and calcium concentrations in newborn umbilical cord serum samples were not different between singleton and twin pregnancies. The comparison of total iron and calcium between mothers and umbilical cord serum indicated significantly lower concentrations in the mothers, with the differences being not homogenous but rather pair-specific. A significant positive correlation between maternal serum and umbilical cord serum calcium concentration was noticed. Prenatal iron supplementation was associated with higher iron concentrations in both mothers and newborns, supporting the efficiency of supplementation and the quality of the study methods. Collectively, the data indicate no significant differences in serum iron and calcium concentrations with regard to singleton or twin pregnancies and the efficiency of iron supplementation during pregnancy for increasing iron status.

Alterations in Antioxidant Micronutrient Concentrations in Placental Tissue, Maternal Blood and Urine and the Fetal Circulation in Pre-eclampsia

Trace elements such as selenium and zinc are vital components of many enzymes, including endogenous antioxidants, and can interact with each other. Women with pre-eclampsia, the hypertensive disease of pregnancy, have been reported as having changes in some individual antioxidant trace elements during pregnancy, which are related to maternal and fetal mortality and morbidity. We hypothesised that examination of the three compartments of (a) maternal plasma and urine, (b) placental tissue and (c) fetal plasma in normotensive and hypertensive pregnant women would allow identification of biologically significant changes and interactions in selenium, zinc, manganese and copper. Furthermore, these would be related to changes in the angiogenic markers, placental growth factor (PlGF) and Soluble Fms-Like Tyrosine Kinase-1 (sFlt-1) concentrations. Venous plasma and urine were collected from healthy non-pregnant women (n = 30), normotensive pregnant controls (n = 60) and women with pre-eclampsia (n = 50) in the third trimester. Where possible, matched placental tissue samples and umbilical venous (fetal) plasma were also collected. Antioxidant micronutrient concentrations were measured by inductively coupled plasma mass-spectrometry. Urinary levels were normalised to creatinine concentration. Plasma active PlGF and sFlt-1 concentrations were measured by ELISA. Maternal plasma selenium, zinc and manganese were all lower in women with pre-eclampsia (p < 0.05), as were fetal plasma selenium and manganese (p < 0.05 for all); maternal urinary concentrations were lower for selenium and zinc (p < 0.05). Conversely, maternal and fetal plasma and urinary copper concentrations were higher in women with pre-eclampsia (p < 0.05). Differences in placental concentrations varied, with lower overall levels of selenium and zinc (p < 0.05) in women with pre-eclampsia. Maternal and fetal PlGF were lower and sFlt-1 higher in women with pre-eclampsia; maternal plasma zinc was positively correlated with maternal plasma sFlt-1 (p < 0.05). Because of perceptions that early- and late-onset pre-eclampsia have differing aetiologies, we subdivided maternal and fetal data accordingly. No major differences were observed, but fetal sample sizes were small following early-onset. Disruption in these antioxidant micronutrients may be responsible for some of the manifestations of pre-eclampsia, including contributing to an antiangiogenic state. The potential benefits of mineral supplementation, in women with deficient intakes, during pregnancy to reduce pre-eclampsia remain an important area for experimental and clinical research.

Associations Between Late-Onset Preeclampsia and the Use of Calcium-Based Antacids and Proton Pump Inhibitors During Pregnancy: A Prospective Cohort Study

Purpose

Preeclampsia is a leading cause of maternal morbidity and mortality. Calcium-based antacids and proton pump inhibitors (PPIs) are commonly used during pregnancy to treat symptoms of gastroesophageal reflux disease. Both have been hypothesized to reduce the risk of preeclampsia. We determined associations of calcium-based antacid and PPI use during pregnancy with late-onset preeclampsia (≥34 weeks of gestation), taking into account dosage and timing of use.

Patients and Methods

We included 9058 pregnant women participating in the PRIDE Study (2012–2019) or The Dutch Pregnancy Drug Register (2014–2019), two prospective cohorts in The Netherlands. Data were collected through web-based questionnaires and obstetric records. We estimated risk ratios (RRs) for late-onset preeclampsia for any use and trajectories of calcium-based antacid and PPI use before gestational day 238, and hazard ratios (HRs) for time-varying exposures after gestational day 237.

Results

Late-onset preeclampsia was diagnosed in 2.6% of pregnancies. Any use of calcium-based antacids (RR 1.2 [95% CI 0.9–1.6]) or PPIs (RR 1.4 [95% CI 0.8–2.4]) before gestational day 238 was not associated with late-onset preeclampsia. Use of low-dose calcium-based antacids in gestational weeks 0–16 (<1 g/day; RR 1.8 [95% CI 1.1–2.9]) and any use of PPIs in gestational weeks 17–33 (RR 1.6 [95% CI 1.0–2.8]) seemed to increase risks of late-onset preeclampsia. We did not observe associations between late-onset preeclampsia and use of calcium-based antacids (HR 1.0 [95% CI 0.6–1.5]) and PPIs (HR 1.4 [95% CI 0.7–2.9]) after gestational day 237.

Conclusion

In this prospective cohort study, use of calcium-based antacids and PPIs during pregnancy was not found to reduce the risk of late-onset preeclampsia.

Longitudinal Assessment of Calcium and Magnesium Levels in Women with Preeclampsia

The present study reports the levels of maternal serum calcium and magnesium from early pregnancy until delivery, along with cord levels, in women who developed preeclampsia (PE) and compares them with those without PE. A total of 324 pregnant women (216 non-PE and 108 PE women) were included in this retrospective case-control study of prospectively collected data nested in an observational cohort study. Maternal blood was collected at 4 time points during pregnancy (V1 = 11-14 weeks, V2 = 18-22 weeks, V3 = 26-28 weeks, and V4 = at delivery) and umbilical cord blood at delivery. Independent t tests were used to compare calcium, magnesium, and their ratio between two groups, and their associations with PE were studied using regression models. Calcium levels were similar between groups at all time points. Magnesium levels were lower (p = 0.021) at V2 in PE group as compared with non-PE group. Maternal calcium and magnesium levels were negatively associated, with blood pressure in early pregnancy. In fully adjusted logistic regression analysis, lower magnesium levels were associated with an increased risk of PE at V2 (OR 0.25 [95% CI 0.07, 0.94] p = 0.04). Lower magnesium in mid-pregnancy was associated with higher risk of PE. These changes were observed before the diagnosis of PE, thereby suggesting that they may have a role in the etiology of PE.

Maternal nutritional risk factors for pre-eclampsia incidence: findings from a narrative scoping review

BACKGROUND

Pre-eclampsia is a leading cause of maternal mortality and morbidity that involves pregnancy-related stressors on the maternal cardiovascular and metabolic systems. As nutrition is important to support optimal development of the placenta and for the developing fetus, maternal diets may play a role in preventing pre-eclampsia. The purpose of this scoping review is to map the maternal nutritional deficiencies and imbalances associated with pre-eclampsia incidence and discuss evidence consistency and linkages with current understandings of the etiology of pre-eclampsia.

METHODS

A narrative scoping review was conducted to provide a descriptive account of available research, summarize research findings and identify gaps in the evidence base. Relevant observational studies and reviews of observational studies were identified in an iterative two-stage process first involving electronic database searches then more sensitive searches as familiarity with the literature increased. Results were considered in terms of their consistency of evidence, effect sizes and biological plausibility.

RESULTS

The review found evidence for associations between nutritional inadequacies and a greater risk of pre-eclampsia. These associations were most likely mediated through oxidative stress, inflammation, maternal endothelial dysfunction and blood pressure in the pathophysiology of pre-eclampsia. Maternal nutritional risk factors for pre-eclampsia incidence with the strongest consistency, effect and biological plausibility include vitamin C and its potential relationship with iron status, vitamin D (both on its own and combined with calcium and magnesium), and healthy dietary patterns featuring high consumption of fruits, vegetables, whole grains, fish, seafood and monounsaturated vegetable oils. Foods high in added sugar, such as sugary drinks, were associated with increased risk of pre-eclampsia incidence.

CONCLUSION

A growing body of literature highlights the involvement of maternal dietary factors in the development of pre-eclampsia. Our review findings support the need for further investigation into potential interactions between dietary factors and consideration of nutritional homeostasis and healthy dietary patterns. Further research is recommended to explore gestational age, potential non-linear relationships, dietary diversity and social, cultural contexts of food and meals.

Maternal serum zinc level is associated with risk of preeclampsia: A systematic review and meta-analysis

Background

Preeclampsia (PE) is a multi-organ syndrome that onsets in the second half of pregnancy. It is the second leading cause of maternal death globally. The homeostasis of zinc (Zn) levels is important for feto-maternal health.

Objective

We aimed to collect all studies available to synthesize the evidence regarding the association between maternal Zn levels and the risk of preeclampsia.

Methods

A systematic review and meta-analysis was conducted via searching seven electronic databases [PubMed, Web of Science, Embase, African Journals Online (AJOL), ClinicalTrial.gov, and two Chinese databases: Wanfang and Chinese National Knowledge Infrastructure, CNKI]. Studies reporting maternal serum Zn levels in pregnant women with or without preeclampsia were included. Eligible studies were assessed through Newcastle-Ottawa Scale (NOS) and the meta-analysis was performed via RevMan and Stata. The random-effects method (REM) was used for the meta-analysis with 95% confidence interval (CI). The pooled result was assessed using standard mean difference (SMD). The heterogeneity test was carried out using I 2 statistics, and the publication bias was evaluated using Begg's and Egger's test. Meta-regression and sensitivity analysis was performed via Stata software.

Results

A total of 51 studies were included in the final analysis. 6,947 participants from 23 countries were involved in our study. All studies went through the quality assessment. The pooled results showed that maternal serum Zn levels were lower in preeclamptic women than in healthy pregnant women (SMD: -1.00, 95% CI: -1.29, -0.70). Sub-group analysis revealed that geographical, economic context, and disease severity may further influence serum Zn levels and preeclampsia.

Limitations

There are significant between-study heterogeneity and publication bias among included studies.

Conclusions

A lower level of maternal Zn was associated with increased risks of preeclampsia. The associations were not entirely consistent across countries and regions worldwide.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=337069, Identifier: CRD42022337069.

Association between trace elements and preeclampsia: A retrospective cohort study

BACKGROUND

Preeclampsia is the main cause of maternal and perinatal death. Multiple studies suggest that trace elements were associated with preeclampsia, but the results varied, and less known about early or mid-term pregnancy of trace elements and preeclampsia. We aim to explore the association between mid-term pregnancy trace elements levels and preeclampsia.

METHODS

The retrospective cohort study was consecutively conducted in Foshan Fosun Chancheng Hospital, Guangdong Province, China, from August 1, 2019, to November 30, 2019. Trace elements are derived from the laboratory data system, measured in maternal whole blood during 12-27 (+6) weeks of pregnancy by flame atomic absorption spectrometer method. Preeclampsia diagnosis and covariance were ascertained from the electronic medical records system. We used multivariable logical regression to estimate odds ratios (OR) and 95% CIs.

RESULTS

A total of 2186 participants were included in this study, and 59 (2.70%) women developed preeclampsia. After multivariable adjustment, the OR of Mg levels for preeclampsia was 0.35 (95%CI:0.06,2.20). The fifth quintiles of Mg were associated with 0.29 (95% CI：0.10,0.85) times lower risk of preeclampsia compared with the first quintile, with a dose-response trend (P for trend = 0.056). Per 1 µmol/L increment in Cu was associated with 11% lower risk of preeclampsia (OR=0.89; 95% CI, 0.78,1.02). Compared with the first quintile, the second, third，fourth，fifth quintile of Cu was associated with a odd ratio of 0.12 (95% CI:0.03,0.43),0.67 (95% CI:0.30,1.48),0.33 (95% CI:0.15,0.76) and 0.26 (95% CI:0.10,0.66),respectively. Null associations were observed for Zn, Fe, Ca.

CONCLUSIONS

Higher blood Mg and Cu levels in mid-term pregnancy were associated with lower preeclampsia risk.

Association of the Serum Folate and Total Calcium and Magnesium Levels Before Ovarian Stimulation With Outcomes of Fresh In Vitro Fertilization Cycles in Normogonadotropic Women

Background

Women of reproductive age are recommended to consume folic acid and other supplements before conception and during pregnancy. We aimed to investigate the association of the serum folate and total magnesium (Mg) and calcium (Ca) levels before ovarian stimulation with the outcomes of assisted reproductive technology (ART) in normogonadotropic women.

Methods

We used a subanalysis of data obtained from a multicentre, randomized prospective study (NCT03088137). A total of 110 normogonadotropic, non-advanced aged, non-obese women with tubal and/or male infertility factors were enrolled for the single fresh ovarian stimulation GnRH antagonist cycle. The main outcome measures were the total oocyte yield, mature oocytes, fertilization rate, biochemical, clinical pregnancy, and live birth. Multivariable generalized linear models adjusted for covariates were used with a Poisson distribution and the log link function for adjusted oocyte counts, and a binomial distribution and the log link function were used for adjusted clinical ART outcomes.

Results

The medians (interquartile range (IQR)) were as follows: baseline serum folate, 20.55 ng/ml (10.8, 32.9); Mg, 19.4 mg/L (18.7, 20.7); Ca, 94 mg/L (91.2, 96.4); and Ca/Mg ratio, 4.78 (4.55, 5.02). Women with higher serum folate concentrations (Q4≥33.0 ng/ml) had significantly lower total numbers of oocytes retrieved (adjusted mean (95% CI) 9.2 (7.6-11.3) vs 12.9 (10.9-15.4, p-trend=0.006)) and lower odds ratios (ORs) (95% CI) of 0.12 (0.02, 0.79) for clinical pregnancy and 0.10 (0.01, 0.70) for live birth compared with women in the lowest quartile (<10.8 ng/ml), all p-trend<0.001. Women in the highest Ca/Mg ratio quartile (≥5.02) had ORs (95% CI) of 6.58 (1.31, 33.04) for biochemical pregnancy, 4.85 (1.02, 23.08) for clinical pregnancy and 4.07 (0.83, 19.9) for the live birth rate compared with women in the lowest quartile (<4.55), all p-trend<0.001.

Conclusions

Using multivariable models, we suggested that a baseline elevated serum folate level (≥33.0 ng/ml) and a lower Ca/Mg ratio were associated with worse ART outcomes in normogonadotropic women. Our findings might be useful for choosing safe dosages of folate, calcium, magnesium and complex supplementation for both fertile women and women undergoing infertility treatment. Further preconception large-scale studies with known micro- and macronutrient statuses of both parents and serum folate, Ca, Mg, and hormone levels, are needed.

Maternal Serum Levels of Zinc, Copper, and Thiols in Preeclampsia Patients: a Case-Control Study

Preeclampsia is one of the leading causes of maternal mortality-morbidity, and environmental factors act as the main driving force for the development of disease in genetically lean women. Trace element levels (zinc, copper) and thiol state (total, native thiol) may affect involved risk factors and play a role in the pathogenesis. The objective of our study is to assess trace element and thiol levels in patient and control groups. A total number of 88 pregnant women (in their third trimester) included 43 preeclampsia patients and 45 normotensive pregnant women as controls. The main findings of this study were the significantly elevated copper levels and decreased thiol levels (native and total thiols) in the patient group compared to controls (p < 0.05). Disulfide levels were not statistically different between the groups (p > 0.05). In patients, the predictive cutoff value of copper was 224 μg/dL and was 1.19 for the copper/native thiol ratio. Zinc levels were not statistically different between the two groups. Correlation analysis revealed no relationship between zinc-copper and zinc-total thiol levels in patients, while a positive correlation was evident in controls (zinc-copper, p < 0.05, r = 0.425, and zinc-total thiol levels, p < 0.05, r = 0.642). Patients had marginally high ALT and AST values in the normal range, and a significant difference was found between the two groups (p < 0.05). According to these results, elevated copper levels and decreased thiol levels may have a value for early prediction. The mechanisms that may be responsible for the altered element and thiol status have been discussed here in the context of oxidative stress.

Ratio of Serum Calcium to Magnesium Levels on Pregnancy with and without Preeclampsia

BACKGROUND Preeclampsia increases maternal and perinatal mortality and is affected by calcium and magnesium levels. Reduced extracellular levels of calcium and magnesium constitute the pathogenesis of eclampsia. A reduction in the calcium-magnesium ratio may aid in the detection and prevention of preeclampsia. MATERIAL AND METHODS This was an analytical observational study with a cross-sectional design, including patients with and without preeclampsia (inpatient and outpatient). A total of 246 patients were included in this research; 138 patients had preeclampsia and 108 patients did not. All examinations of magnesium and calcium levels at the Hasan Sadikin Hospital Clinical Pathology laboratory were conducted using an ion selective electrode modified with methylthymol blue complexometric titration. RESULTS Patients with preeclampsia had significantly higher average serum magnesium and calcium levels than did patients without preeclampsia (2.85 vs 2.09, P=0.0001; 4.45 vs 4.85, P=0.025, respectively). Patients with preeclampsia demonstrated significantly lower serum calcium-magnesium ratios than did patients without preeclampsia (1.98 vs 2.60, P=0.0001). Receiver operating characteristic curve analysis on the serum calcium-magnesium ratio showed an area under the curve of 68.0% (P=0.0001), with a cutoff value of 2.36 (sensitivity 64.8%, specificity 62.3%), indicating that patients with serum calcium-magnesium ratios of <2.36 were predicted to have a risk of preeclampsia. CONCLUSIONS Patients with preeclampsia had significantly lower serum calcium-magnesium ratios than did patients without preeclampsia; therefore, a low calcium-magnesium ratio could be a risk factor for preeclampsia.

Effect of maternal zinc supplementation or zinc status on pregnancy complications and perinatal outcomes: An umbrella review of meta-analyses

Zinc is an essential trace element involved in different physiological functions. During pregnancy, it plays a crucial role in healthy embryogenesis. This umbrella review, therefore, aimed to summarize the existing literature of meta-analyses evaluating the effect of maternal zinc supplementation or zinc status on maternal and neonatal outcomes. Two databases, PubMed and Scopus, were selected to search the available literature without any temporal restriction. The literature search was performed during October 2020 and a total of 192 records were identified through the literature search. After screening the titles and applying the inclusion/exclusion criteria, finally, 15 articles were included in this umbrella review. This umbrella review showed that maternal zinc supplements reduce the risk of preterm birth. Although no substantial effect of zinc supplements was found for other feto-maternal outcomes. Also, we found a significant relationship between low maternal zinc status and risk of pregnancy complications. Zinc supplements reduce the risk of preterm birth. Long-term interventions and cohort studies are needed for future research directions. Further studies and a thorough investigation will help to decide the recommended zinc dose or intake during pregnancy.

Effects of prenatal micronutrients supplementation timing on pregnancy-induced hypertension: Secondary analysis of a double-blind randomized controlled trial

In this secondary analysis of data from a double‐blind randomized controlled trial (clinicaltrials.gov identifier: NCT00133744) of micronutrient supplementation (multiple micronutrients [MMN], iron–folic acid [IFA] and folic acid [FA] alone), we examined the potential modifying effect of gestational age at enrolment on the association of antenatal supplementation and pregnancy‐induced hypertension (PIH). We included 18,775 nulliparous pregnant women with mild or no anaemia who were enrolled at 20 weeks of gestation or earlier from five counties of northern China. Women were randomly assigned to receive daily FA, IFA or MMN from enrolment until delivery. We used logistic regression to evaluate the association between PIH and timing of micronutrient supplementation. The incidence of PIH was statistically significantly lower among women who began MMN supplementation before 12 gestational weeks compared with women who began MMN supplementation at 12 weeks or later (RR = 0.74, 95% CI: 0.60–0.91). A similar protective effect was observed for both early‐onset (<28 weeks, RR 0.45, 0.21–0.96) and late‐onset of PIH (≥28 weeks, RR 0.77, 0.63–0.96). No statistically significant association was observed between PIH occurrence and timing of supplementation for FA or IFA. Maternal MMN supplementation and antenatal enrolment during the first trimester of pregnancy appeared to be of importance in preventing both early‐ and late‐onset of PIH.

Risk factors and comorbidities associated with magnesium deficiency in pregnant women and women with hormone-related conditions: analysis of a large real-world dataset

BACKGROUND

An accumulating body of literature indicates that magnesium deficiency is associated with a number of hormone-related conditions (HRC) in women, and epidemiological studies are needed to assess its prevalence and risk factors. Here, we present a secondary analysis of data pooled from four large observational studies that assessed magnesium deficiency among pregnant women and women with HRC across the Russian Federation.

METHODS

The main objective of this analysis was to estimate the prevalence of magnesium deficiency in this population and to describe risk factors and comorbidities associated with low serum magnesium. Univariate logistic regression analysis was performed to identify the risk factors and comorbid conditions associated with an increased risk of low serum magnesium level.

RESULTS

A total of 983 pregnant women and 9444 women with HRC were eligible for analysis. Prevalence of hypomagnesemia (magnesium serum level cut-off < 0.66 mmol/L/< 0.8 mmol/L) was 34.0%/78.9% in pregnant women and 21.4%/54.8% in women with HRC. The highest prevalence of magnesium deficiency was observed for osteoporosis and climacteric syndrome. Risk factors included diastolic blood pressure, previous pregnancy complications, infections and edema for pregnant women, and age, body mass index, and various comorbidities for women with HRC.

CONCLUSIONS

These results confirm the high prevalence of hypomagnesemia in pregnant women and women with HRC and underline the importance of routine screening, since risk factors are mostly non-specific.

Elemental Metabolomics for Prediction of Term Gestational Outcomes Utilising 18-Week Maternal Plasma and Urine Samples

A normal pregnancy is essential to establishing a healthy start to life. Complications during have been associated with adverse perinatal outcomes and lifelong health problems. The ability to identify risk factors associated with pregnancy complications early in gestation is vitally important for preventing negative foetal outcomes. Maternal nutrition has been long considered vital to a healthy pregnancy, with micronutrients and trace elements heavily implicated in maternofoetal metabolism. This study proposed the use of elemental metabolomics to study multiple elements at 18 weeks gestation from blood plasma and urine to construct models that could predict outcomes such as small for gestational age (SGA) (n = 10), low placental weight (n = 18), and preterm birth (n = 13) from control samples (n = 87). Samples collected from the Lyell McEwin Hospital in Adelaide, South Australia, were measured for 27 plasma elements and 37 urine elements by inductively coupled plasma mass spectrometry. Exploratory analysis indicated an average selenium concentration 20 μg/L lower than established reference ranges across all groups, low zinc in preterm (0.64 μg/L, reference range 0.66-1.10 μg/L), and higher iodine in preterm and SGA gestations (preterm 102 μg/L, SGA 111 μg/L, reference range 40-92 μg/L). Using random forest algorithms with receiver operating characteristic curves, low placental weight was predicted with 86.7% accuracy using plasma, 78.6% prediction for SGA with urine, and 73.5% determination of preterm pregnancies. This study indicates that elemental metabolomic modelling could provide a means of early detection of at-risk pregnancies allowing for more targeted monitoring of mothers, with potential for early intervention strategies to be developed.

A clinical evaluation of the alterations in the level of serum zinc, copper, iron, and manganese in the ischemic heart disease patients of Bangladesh - A case-control study

Background

Ischemic heart disease (IHD) is a major cause of death globally. Countries vary in their rates, and changes have occurred over time. Nowadays, developing countries pose new public health challenges.

Objectives

The objective of the present study was to appraise the alterations in the levels of serum Zn, Cu, Fe, and Mn that occur in patients with ischemic heart disease and to depict the correlations of the effects of these changes that lead to the pathogenesis of IHD.

Methods

Zn, Cu, Fe, and Mn in the IHD patients were determined by Atomic Absorption Spectroscopy (AAS).

Results

This study evaluated 52 patients with IHD, and 61 healthy volunteers served as controls. The primary outcomes of interest were explored regarding the correlations of the serum levels of these trace elements in patients with IHD. The secondary outcomes were explored in terms of inter-element relations to connect them with the pathogenesis of IHD. Our study found significantly reduced levels of Zn and Cu (2.50 ± 0.19 mg/L and 2.52 ± 0.17 mg/L, respectively) and an elevated level of Fe (148.97 ± 17.25 mg/L) in the patient group with IHD. The level of Mn (7.32 ± 1.23 mg/L) was elevated in the sera of the patients with ischemic heart disease (IHD) compared to healthy control subjects.

Conclusion

Our results indicate strong associations of the pathogenesis of IHD with depleted serum levels of Zn and Cu and elevated Fe and Mn levels, which may provide a prognostic tool for the treatment of this concerning the disease.

Chemical elements and preeclampsia - An overview of current problems, challenges and significance of recent research

OBJECTIVES

Data on the elemental status, redistribution of the elements, role of occupational exposure and dietary assessment in preeclampsia (PE) are scarce. There are many disparities in the findings of essential and non-essential elements' role in PE. In this article we overview the changes in the content of selected elements in pregnancy complicated with the disorder of complex and not fully understood etiology. We have focused on important limitations and highlighted shortcomings in research from the last ten years period.

METHODS

The Scopus and PubMed electronic databases have been searched for English-language articles published within the time interval 2008-2018, with full text available and with the key words "preeclampsia" and "chemical element" (i.e. separately: Cd, Pb, As, Ni, Mo, Co, Cr, Mn, Se, I, Fe, Sr, Cu, Zn, Mg, K and Na) appearing in the title, abstract or keywords.

RESULTS

A total of 48 publications were eligible for this overview. Surprisingly only 4% of papers considered environmental exposure, 8%- diet and 2 %- comorbid diseases. In most published papers, occupational exposure was neglected. Meta-analysis was possible for seven elements in serum (Ca, Cu, Fe, Mg, Mn, Se, Zn), and two elements (Se, Zn) in plasma. It showed negative shift for most elements, however only several were statistically significant.

CONLUSIONS

The overview of the published data on PE and chemical elements yields varied results. Some of the reasons may be the difference in not duly validated method of determination, and huge discrepancies in study designs. The lack of detailed description of studied and control population and small number of samples constitute the most common limitations of such studies. Many of them describe the use of a single analytical procedure, therefore the quality of research may be insufficient to obtain reliable results. A history of elements' status and intake before and during pregnancy is usually not examined. Dietary assessment should be done at different stages of pregnancy, and whenever possible in the periconceptional period as well. It still needs to be established whether the deficiency of certain elements or their excess may be an etiopathogenic factor and a developmental cause of PE, and if it may serve as a target of actions in the causal treatment or even prevention of the occurrence of this disease.

Elemental metabolomics in human cord blood: Method validation and trace element quantification

BACKGROUND

Trace elements are an essential requirement for human health and development and changes in trace element status have been associated with pregnancy complications such as gestational diabetes mellitus (GDM), pre-eclampsia (PE), fetal growth restriction (FGR), and preterm birth. Elemental metabolomics, which involves the simultaneous quantification and characterisation of multiple elements, could provide important insights into these gestational disorders.

METHODS

This study used an Agilent 7900 inductively coupled plasma mass spectrometer (ICP-MS) to simultaneously measure 68 elements, in 166 placental cord blood samples collected from women with various pregnancy complications (control, hypertensive, PE, GDM, FGR, pre-term, and post-term birth).

RESULTS

There were single element differences across gestational outcomes for elements Mg, P, Cr, Ni, Sr, Mo, I, Au, Pb, and U. Hypertensive and post-term pregnancies were significantly higher in Ni concentrations when compared to controls (control = 2.74 μg/L, hypertensive = 6.72 μg/L, post-term = 7.93 μg/L, p < 0.05), iodine concentration was significantly higher in post-term pregnancies (p < 0.05), and Pb concentrations were the lowest in pre-term pregnancies (pre-term = 2.79 μg/L, control = 4.68 μg/L, PE = 5.32 μg/L, GDM = 8.27 μg/L, p < 0.01). Further analysis was conducted using receiver operating characteristic (ROC) curves for differentiating pregnancy groups. The ratio of Sn/Pb showed the best diagnostic power in discriminating between control and pre-term birth with area under the curve (AUC) 0.86. When comparing control and post-term birth, Mg/Cr (AUC = 0.84), and Cr (AUC = 0.83) had the best diagnostic powers. In pre-term and post-term comparisons Ba was the best single element (81.5%), and P/Cu provided the best ratio (91.7%).

CONCLUSIONS

This study has shown that analysis of multiple elements can enable differentiation between fetal cord blood samples from control, hypertensive, PE, GDM, FGR, pre and post-term pregnancies. This data highlights the power of elemental metabolomics and provides a basis for future gestational studies.

BRAzil magnesium (BRAMAG) trial: a double-masked randomized clinical trial of oral magnesium supplementation in pregnancy

Background

There is conflicting evidence about the role of oral magnesium supplementation in the prevention of preterm birth and related adverse outcomes. The objective of this study was to compare magnesium citrate with placebo in the prevention of adverse perinatal and maternal outcomes among women at higher risk.

Methods

This multicenter, double-masked, placebo-controlled randomized superiority clinical trial compared oral magnesium citrate 300 mg to matched placebo, from 12 to 20 weeks’ gestation until delivery. This trial was completed in three centers in northeastern Brazil. Eligible women were those with a singleton pregnancy and ≥ 1 risk factor, such as prior preterm birth or preeclampsia, or current chronic hypertension or pre-pregnancy diabetes mellitus, age > 35 years or elevated body mass index. The primary perinatal composite outcome comprised preterm birth < 37 weeks’ gestation, stillbirth > 20 weeks, neonatal death or NICU admission < 28 days after birth, or small for gestational age birthweight < 3rd percentile. The co-primary maternal composite outcome comprised preeclampsia or eclampsia < 37 weeks, severe gestational hypertension < 37 weeks, placental abruption, or maternal stroke or death during pregnancy or ≤ 7 days after delivery.

Results

Analyses comprised 407 women who received magnesium citrate and 422 who received placebo. The perinatal composite outcome occurred among 75 (18.4%) in the magnesium arm and 76 (18.0%) in the placebo group – an adjusted odds ratio (aOR) of 1.10 (95% CI 0.72–1.68). The maternal composite outcome occurred among 49 (12.0%) women in the magnesium arm and 41 women (9.7%) in the placebo group – an aOR of 1.29 (95% CI 0.83–2.00).

Conclusions

Oral magnesium citrate supplementation did not appear to reduce adverse perinatal or maternal outcomes in high-risk singleton pregnancies.

Trial registration

ClinicalTrials.gov NCT02032186, registered January 9, 2014.

Serum calcium-magnesium ratio in women with pre-eclampsia at a tertiary hospital in Nigeria

OBJECTIVE

To determine the serum calcium-magnesium ratio in pre-eclampsia and compare with normotensives.

METHODS

A case-control study was conducted in a tertiary hospital between October 2017 and March 2018 among 81 pregnant women (27 cases and 54 controls matched for age, gestational age, and parity). An interviewer-administered questionnaire was used to obtain data on demography/clinical history. Venous blood was collected without stasis and sent for biochemical analysis. Statistical analysis used IBM SPSS 21.0.

RESULTS

The levels of serum Ca²⁺ (7.73 + 1.24 vs 9.17 + 0.77; P<0.001), Ca²⁺ -Mg²⁺ ratio (3.36 + 0.60 vs 3.83 + 0.41; P=0.001), and Mg²⁺ (2.35 + 0.35 vs 2.41 + 0.16; P=0.469) were lower among cases. Serum Ca²⁺ level correlated negatively with systolic (r=0.45, P=0.05) and diastolic blood pressure (r=0.50, P=0.010) among the cases. Hypocalcemia was a risk factor (adjusted odds ratio [AOR] 7.63, 95% confidence interval [CI] 1.64-35.37) while social classes 2 and 3 were protective factors (AOR 0.01, 95% CI 0.00-0.46 and AOR 0.01, 95% CI 0.00-0.24, respectively) against pre-eclampsia.

CONCLUSION

The result of this research supported the implication of micronutrients in pre-eclampsia and may help to understand the pathophysiological process of pre-eclampsia. It will also help to establish and enhance existing preventive strategies for the condition. The recommendation by WHO on calcium supplementation in pregnancy as a step in preventing the occurrence of pre-eclampsia should be practiced.

Serum calcium level among pregnant women and its association with pre-eclampsia and delivery outcomes: A cross-sectional study from North India

Background:

Calcium requirement increases during pregnancy, thereby increasing the chances of developing hypocalcaemia. Hypocalcaemia may be associated with pregnancy-related complications. Therefore, we planned this study to estimate the prevalence of hypocalcaemia among pregnant women attending secondary care hospital, and to study the association between hypocalcaemia and pregnancy outcomes.

Materials and Methods:

This study was conducted in a secondary level hospital at Ballabgarh, district Faridabad, Haryana, India. Consecutive pregnant women with gestation period more than 28 weeks were enrolled. Dietary calcium intake was ascertained using 24-hour dietary recall method. Serum calcium estimation was done by Biolis 24i auto analyser. Outcome of pregnancy (preterm delivery, low birth weight (LBW) babies, and neonatal mortality) was assessed telephonically 3 months after the enrolment.

Results:

A total of 696 pregnant women were enrolled in the study. Mean (SD) dietary calcium intake and serum calcium level was 796.4 (360.4) mg/day and 9.56 (0.94) mg/dl respectively. Prevalence (95% CI) of hypocalcaemia was 23.9% (20.8 – 27.2%). Serum total calcium level was not associated with dietary calcium intake (p-value = 0.36). Mean serum calcium level was significantly lower in mothers who had LBW babies. Pre-eclampsia, preterm delivery, and neonatal mortality were not associated with serum calcium level.

Conclusion:

Serum calcium level may not be related to dietary calcium level. Hence, the current recommendation of calcium supplementation during antenatal period appears to be inconclusive among our study population.

Association of dietary intake below recommendations and micronutrient deficiencies during pregnancy and low birthweight

Background Pregnancy is associated with biochemical changes leading to increased nutritional demands for the developing fetus that result in altered micronutrient status. The Indian dietary pattern is highly diversified and the data about dietary intake patterns, blood micronutrient profiles and their relation to low birthweight (LBW) is scarce. Methods Healthy pregnant women (HPW) were enrolled and followed-up to their assess dietary intake of nutrients, micronutrient profiles and birthweight using a dietary recall method, serum analysis and infant weight measurements, respectively. Results At enrolment, more than 90% of HPW had a dietary intake below the recommended dietary allowance (RDA). A significant change in the dietary intake pattern of energy, protein, fat, vitamin A and vitamin C (P < 0.001) was seen except for iron (Fe) [chi-squared (χ2) = 3.16, P = 0.177]. Zinc (Zn) deficiency, magnesium deficiency (MgDef) and anemia ranged between 54-67%, 18-43% and 33-93% which was aggravated at each follow-up visit (P ≤ 0.05). MgDef was significantly associated with LBW [odds ratio (OR): 4.21; P = 0.01] and the risk exacerbate with the persistence of deficiency along with gestation (OR: 7.34; P = 0.04). Pre-delivery (OR: 0.57; P = 0.04) and postpartum (OR: 0.37; P = 0.05) anemia, and a vitamin A-deficient diet (OR: 3.78; P = 0.04) were significantly associated with LBW. LBW risk was much higher in women consuming a vitamin A-deficient diet throughout gestation compared to vitamin A-sufficient dietary intake (OR: 10.00; P = 0.05). Conclusion The studied population had a dietary intake well below the RDA. MgDef, anemia and a vitamin A-deficient diet were found to be associated with an increased likelihood of LBW. Nutrient enrichment strategies should be used to combat prevalent micronutrient deficiencies and LBW.

Maternal serum uric acid and calcium as predictors of hypertensive disorder of pregnancy: A case control study

OBJECTIVES

Compare serum uric acid and calcium levels among normotensive and hypertensive pregnant women, to compare maternal and perinatal outcomes in two groups.

MATERIALS AND METHODS

Prospective case control study was conducted after ethical approval in Obstetrics and Gynaecology department of rural tertiary care centre of Northern India, over seven months. Total 220 antenatal women ≥34 weeks of gestation with 110 cases having hypertensive disorder of pregnancy and 110 controls with normal blood pressure were compared for maternal uric acid and calcium levels and maternal, perinatal outcomes.

RESULTS

Mean ± SD values of uric acid and calcium in control group was 4.42 ± 1.42 mg/dl and 8.94 ± 0.6 mg/dl, whereas in cases they were 6.8 ± 2.72 mg/dl and 8.61 ± 0.78 mg/dl (p < 0.05). Induced labour followed by lower segment caesarean section was the most common mode of delivery in hypertensive cases, whereas, in controls, the majority had spontaneous onset of labour and delivered vaginally (p < 0.05). Hypertensive women with higher uric acid and lower calcium had adverse perinatal outcome as compared to controls (p < 0.05). Mean ± SD of neonatal birth weight in controls was 2.81 ± 0.295 Kg and in cases 2.56 ± 0.421 Kg. Neonatal birth weight was significantly associated with maternal uric acid than calcium in hypertensive women. Cases with hyperuricemia and low calcium levels had adverse overall outcome as compared to controls.

CONCLUSION

Maternal hyperuricemia and hypocalcaemia was associated with adverse maternal, perinatal outcomes in women with hypertensive disorder of pregnancy as compared to healthy normotensive women.

Elemental Metabolomics and Pregnancy Outcomes

Trace elements are important for human health and development. The body requires specific micronutrients to function, with aberrant changes associated with a variety of negative health outcomes. Despite this evidence, the status and function of micronutrients during pregnancy are relatively unknown and more information is required to ensure that women receive optimal intakes for foetal development. Changes in trace element status have been associated with pregnancy complications such as gestational diabetes mellitus (GDM), pre-eclampsia (PE), intrauterine growth restriction (IUGR), and preterm birth. Measuring micronutrients with methodologies such as elemental metabolomics, which involves the simultaneous quantification and characterisation of multiple elements, could provide insight into gestational disorders. Identifying unique and subtle micronutrient changes may highlight associated proteins that are affected underpinning the pathophysiology of these complications, leading to new means of disease diagnosis. This review will provide a comprehensive summary of micronutrient status during pregnancy, and their associations with gestational disorders. Furthermore, it will also comment on the potential use of elemental metabolomics as a technique for disease characterisation and prediction.

Maternal Serum Uric Acid as a Predictor of Severity of Hypertensive Disorders of Pregnancy: A Prospective Cohort Study

Objective: To assess the relationship between maternal serum uric acid and severity of Hypertensive disorders of pregnancy in a rural tertiary care centre.

Materials and Methods: Present study was conducted in Obstetrics and Gynaecology department of rural tertiary care cen-tre of Northern India over seven months (October 2016-May 2017) on 110 women admitted with a Hypertensive disorder of pregnancy (Gestational hypertension, Pre-eclampsia, Eclampsia) at ≥34 weeks gestation. Maternal serum uric acid levels were compared in three groups in relation to disease severity, mode of delivery, maternal outcome.

Results: Of total 110 women with a Hypertensive disorder of pregnancy; 35 (31.81%) had Gestational Hypertension, 49 (44.54%) preeclampsia and 26 (23.63%) had eclampsia. Mean±SD values for serum uric acid were 5.47±1.93 mg/dl in women with Gestational Hypertension; 6.72±2.15 mg/dl in Pre-eclampsia and 8.71±2.97 mg/dl in the eclamptic group. Of 110 women 34(97.14%) with gestational hypertension, 27(55.10%) with pre-eclampsia and one (3.85%) with eclampsia re-mained stable in post-partum period, 17 (34.69%) women with severe pre-eclampsia and 15 (57.69%) with eclampsia re-quired intensive care in postpartum period and one (2.86%) women with gestational hypertension, five (10.20%) with pre-eclmapsia and ten (38.46%) with eclampsia required ventilator support and high dependency unit care. Of these 16 women with the severe disease, ten succumbed to death. Also, in women with serum uric acid,>6mg/dl, most common mode of de-livery was a lower segment cesarean section (50.90%).

Conclusion: Significant correlation was observed between maternal serum uric acid, disease severity and maternal outcome.

Preterm and term preeclampsia: differences in biochemical parameter and pregnancy outcomes

OBJECTIVE

To analyze the similarities and differences in the clinical parameters, laboratory biomarkers, and pregnancy outcomes between preterm and term preeclampsia (PE).

METHODS

Data on 185 women diagnosed with PE were collected from a Jiangsu Province Hospital from January 2017 to December 2017 and analyzed. 74 (40%) patients were diagnosed with preterm PE, of which 70 (94.6%) patients with PE with severe features (PEs) and the rest with PE. 111 (60%) patients were diagnosed with term PE, of which 54 (48.6%) patients with PEs and the rest with PE.

RESULTS

Preterm PE group had significantly higher blood pressure than that of term PE, with mean delivery at gestational age of 34.3[Formula: see text]2.1 weeks for preterm PE and 39[Formula: see text]1.2 weeks for term PE. Preterm PE group was associated with previous cesarean section and PE history, fetal growth restriction (FGR), non-reassuring fetal status (NRFS), and fetal umbilical artery (UA) systolic velocity/diastolic velocity ratio (S/D R) abnormality, neonatal lower birth weight, lower APGAR score, and higher NICU transfer rate. 74.3% of pregnant women from preterm PE group had proteinuria of +2 to +4, whilst only 37.8% pregnant women from term PE group developed that condition. Liver and renal function, also serum Ca and K were significantly higher in preterm PE.

CONCLUSION

Our study found that preterm PE significantly correlated with higher incidence of PEs, neonatal morbidities, also higher liver and kidney function compared to term PE. These results may be helpful for obstetricians to make accurate quantification of risk regarding every result of antenatal check-up, and perform close follow up if any abnormalities were found on blood pressure, ultrasound, or blood tests.

Identification of placental nutrient transporters associated with intrauterine growth restriction and pre-eclampsia

Background

Gestational disorders such as intrauterine growth restriction (IUGR) and pre-eclampsia (PE) are main causes of poor perinatal outcomes worldwide. Both diseases are related with impaired materno-fetal nutrient transfer, but the crucial transport mechanisms underlying IUGR and PE are not fully elucidated. In this study, we aimed to identify membrane transporters highly associated with transplacental nutrient deficiencies in IUGR/PE.

Results

In silico analyses on the identification of differentially expressed nutrient transporters were conducted using seven eligible microarray datasets (from Gene Expression Omnibus), encompassing control and IUGR/PE placental samples. Thereby 46 out of 434 genes were identified as potentially interesting targets. They are involved in the fetal provision with amino acids, carbohydrates, lipids, vitamins and microelements. Targets of interest were clustered into a substrate-specific interaction network by using Search Tool for the Retrieval of Interacting Genes. The subsequent wet-lab validation was performed using quantitative RT-PCR on placentas from clinically well-characterized IUGR/PE patients (IUGR, n = 8; PE, n = 5; PE+IUGR, n = 10) and controls (term, n = 13; preterm, n = 7), followed by 2D-hierarchical heatmap generation. Statistical evaluation using Kruskal-Wallis tests was then applied to detect significantly different expression patterns, while scatter plot analysis indicated which transporters were predominantly influenced by IUGR or PE, or equally affected by both diseases. Identified by both methods, three overlapping targets, SLC7A7, SLC38A5 (amino acid transporters), and ABCA1 (cholesterol transporter), were further investigated at the protein level by western blotting. Protein analyses in total placental tissue lysates and membrane fractions isolated from disease and control placentas indicated an altered functional activity of those three nutrient transporters in IUGR/PE.

Conclusions

Combining bioinformatic analysis, molecular biological experiments and mathematical diagramming, this study has demonstrated systematic alterations of nutrient transporter expressions in IUGR/PE. Among 46 initially targeted transporters, three significantly regulated genes were further investigated based on the severity and the disease specificity for IUGR and PE. Confirmed by mRNA and protein expression, the amino acid transporters SLC7A7 and SLC38A5 showed marked differences between controls and IUGR/PE and were regulated by both diseases. In contrast, ABCA1 may play an exclusive role in the development of PE.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-4518-z) contains supplementary material, which is available to authorized users.

Micronutrient supplementation during pregnancy and the risk of pregnancy-induced hypertension: A randomized clinical trial

BACKGROUND & AIMS

Increasing evidence suggests that iron-containing multiple micronutrient may reduce the risk of pregnancy-induced hypertension including gestational hypertension or preeclampsia. We aimed to examine whether 30 mg iron plus folic acid or multiple micronutrients during pregnancy reduces the risk of pregnancy-induced hypertension.

METHODS

We conducted a secondary data analysis by the dataset from a double-blind randomized controlled trial in China from 2006 to 2009 that was conducted to investigate the effects of multiple micronutrient supplements on adverse pregnancy outcomes when provided to pregnant women with no/mild anemia. We used logistic regression to estimate the adjusted odds ratio and 95% confidence interval and test for effect modification.

RESULTS

The incidence of pregnancy-induced hypertension was 7.1% (423/5923), 6.3% (374/5933) and 6.3% (372/5914) among the pregnant women who took folic acid only, iron-folic acid and multiple micronutrient supplements, respectively. The adjusted odds ratios associated with iron-folic acid supplements and multiple micronutrient supplements for pregnancy-induced hypertension were both nearly 0.88 (95% confidence interval, 0.76-1.02), compared with folic acid supplements only. Among pregnant women aged 20-24 years, iron-folic acid (adjusted odds ratios: 0.81, 95% confidence interval: 0.67-0.96) or multiple micronutrient supplementation (adjusted odds ratios: 0.83, 95% confidence interval: 0.70-0.99) can significantly reduce the risk of pregnancy-induced hypertension compared to folic acid supplementation.

CONCLUSIONS

Overall, there were no significant differences in pregnancy-induced hypertension across supplement groups. However, among pregnant women aged 20-24 years, iron-containing multiple micronutrient supplementation was associated with a reduced risk of pregnancy-induced hypertension compared with folic acid supplements only.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00133744.

Serum Magnesium Levels in Preterm Infants Are Higher Than Adult Levels: A Systematic Literature Review and Meta-Analysis

Magnesium (Mg) is an essential mineral in the body, impacting the synthesis of biomacromolecules, bone matrix development, energy production, as well as heart, nerve, and muscle function. Although the importance of Mg is evident, reference values for serum Mg (sMg) in pediatric patients (more specifically, in neonates) are not well established. This systematic literature review and meta-analysis (using 47 eligible studies) aims to quantify normal and tolerable ranges of sMg concentrations during the neonatal period and to highlight the factors influencing Mg levels and the importance of regulating sMg levels during pregnancy and birth. In newborns without Mg supplementation during pregnancy, magnesium levels at birth (0.76 (95% CI: 0.52, 0.99) mmol/L) were similar to that of mothers during pregnancy (0.74 (95% CI: 0.43, 1.04) mmol/L), but increased during the first week of life (0.91 (95% CI: 0.55, 1.26) mmol/L) before returning to adult levels. This pattern was also seen in newborns with Mg supplementation during pregnancy, where the average was 1.29 (95% CI: 0.50, 2.08) mmol/L at birth and 1.44 (95% CI: 0.61, 2.27) mmol/L during the first week of life. Factors influencing these levels include prenatal Mg supplementation, gestational age, birth weight, renal maturity/function, and postnatal Mg intake. Elevated Mg levels (>2.5 mmol/L) have been associated with an increased risk of mortality, admission into intensive care, hypotonia, hypotension, and respiratory depression but sMg concentrations up to 2.0 mmol/L appear to be well tolerated in neonates, requiring adequate survey and minimal intervention.

Minerals in Pregnancy and Lactation: A Review Article

Micronutrients (include vitamins and minerals) are essential for normal function, growth and development. Minerals have important effects on the health of the mother and foetus. But biological mechanisms of minerals are not completely understood. Micronutrient deficiency during pregnancy can lead to anaemia, hypertension, obstetric complications and even maternal death and in foetus lead to a fail in growth and development. Mineral deficiency during pregnancy, particularly exist in developing countries. During pregnancy due to the increased demands caused by physiological changes, deficiency is exaggerated and as a result its complications occur. Thus, ensuring to receive enough macronutrients and micronutrients before and during pregnancy, is important. Nevertheless, there are controversies regarding administrating supplements. There are not enough studies about some of the minerals and the challenges remain. Regarding the importance of minerals in pregnancy and lactation, in this review we will analyze the role of them in pregnancy and lactation.

Serum magnesium and calcium in preeclampsia: a comparative study at the Korle-Bu Teaching Hospital, Ghana

Background

A large percentage (16% of maternal mortality in developed countries, compared to 9% in developing countries), is due to hypertensive disorders in pregnancy. The etiology of preeclampsia remains unknown, with poorly understood pathophysiology. Magnesium and calcium play an important role in vascular smooth muscle function and therefore a possible role in the development of preeclampsia.

Aim

We aimed to compare serum magnesium and total calcium levels of preeclamptic and normal pregnant women at the Korle-Bu Teaching Hospital in Ghana.

Patients and methods

A comparative cross-sectional study involving 30 normal pregnant and 30 preeclamptic women with >30 weeks gestation and aged 18–35 years, was conducted at the Korle-Bu Teaching Hospital. Magnesium and calcium were determined using a flame atomic absorption spectrometer.

Results

Mean serum magnesium and total calcium levels in preeclamptic women were 0.70±0.15 and 2.13±0.30 mmol/L, respectively. Mean serum magnesium and total calcium levels in normal pregnant women were 0.76±0.14 and 2.13±0.35 mmol/L, respectively. There was a statistically nonsignificant difference in serum magnesium and total calcium in preeclamptic women compared to normal pregnant women, with p-values of 0.092 and 0.972, respectively.

Conclusion

Serum magnesium and total calcium, therefore, seem not to differ in preeclamptic women compared to normal pregnant women in Ghana.

Serum Calcium, Magnesium, Zinc and Copper Levels in Sudanese Women with Preeclampsia

Background

Although the exact pathophysiology of preeclampsia is not fully understood, several elemental micronutrient abnormalities have been suggested to play a contributory role in preeclampsia.

Aims

To investigate the levels of calcium, magnesium, zinc and copper in women with preeclampsia.

Subjects and Methods

A case—control study was conducted in Omdurman Maternity Hospital, Sudan, during the period of September through December 2014. The cases were women with preeclampsia while healthy pregnant women were the controls. The medical and obstetrics history was gathered using questionnaires. The serum levels of calcium, magnesium, zinc and copper were measured using atomic absorption spectrophotometer.

Results

There was no significant difference between the two groups in their age, gestational age, parity and body mass index. Zinc and copper levels were not significantly different between the two groups. In comparison with the controls, women with preeclampsia had a significantly lower median (inter-quartile) serum calcium [7.6 (4.0─9.6) vs. 8.1 (10.6─14.2), mg/dl, P = 0.032] and higher levels of magnesium [1.9 (1.4─2.5) vs. 1.4 (1.0─1.9) mg/dl; P = 0.003]. In binary logistic regression, lower calcium (OR = 0.73, 95% CI = 0.56 ─ 0.95, P = 0.021) and higher magnesium (OR = 5.724, 95% CI = 1.23 ─ 26.50, P = 0.026) levels were associated with preeclampsia. There were no significant correlations between levels of hemoglobin and these trace elements.

Conclusion

The current study showed significant associations between preeclampsia and serum levels of calcium and magnesium.

Association between Maternal Zinc Status, Dietary Zinc Intake and Pregnancy Complications: A Systematic Review

Adequate zinc stores in the body are extremely important during periods of accelerated growth. However, zinc deficiency is common in developing countries and low maternal circulating zinc concentrations have previously been associated with pregnancy complications. We reviewed current literature assessing circulating zinc and dietary zinc intake during pregnancy and the associations with preeclampsia (PE); spontaneous preterm birth (sPTB); low birthweight (LBW); and gestational diabetes (GDM). Searches of MEDLINE; CINAHL and Scopus databases identified 639 articles and 64 studies were reviewed. In 10 out of 16 studies a difference was reported with respect to circulating zinc between women who gave birth to a LBW infant (≤2500 g) and those who gave birth to an infant of adequate weight (>2500 g), particularly in populations where inadequate zinc intake is prevalent. In 16 of our 33 studies an association was found between hypertensive disorders of pregnancy and circulating zinc; particularly in women with severe PE (blood pressure ≥160/110 mmHg). No association between maternal zinc status and sPTB or GDM was seen; however; direct comparisons between the studies was difficult. Furthermore; only a small number of studies were based on women from populations where there is a high risk of zinc deficiency. Therefore; the link between maternal zinc status and pregnancy success in these populations cannot be established. Future studies should focus on those vulnerable to zinc deficiency and include dietary zinc intake as a measure of zinc status.

A meta-analysis of copper level and risk of preeclampsia: evidence from 12 publications

The association between copper level and risk of preeclampsia (PE) has produced inconsistent results. Thus, a meta-analysis was conducted to summarize the evidence from epidemiological studies for copper level and PE risk. Pertinent studies were identified by a search of PubMed and Web of Knowledge up to April 2016. Standardized mean difference (SMD) was performed to combine the results. Random-effect model (REM) was used. Publication bias was estimated using Egger's regression asymmetry test. Twelve articles (10 case–control studies and 2 cross-sectional studies) involving 442 PE cases and 463 health controls were included in this meta-analysis. Our pooled results suggested that PE patients had a higher copper level compared with healthy pregnancy controls [summary SMD=0.69, 95% CI: 0.54–0.84, I²=96.7%; P<0.001]. The association was also significant in Asian population [SMD=0.73, 95% CI=0.57–0.90, I²=97.3%] and European populations [SMD=0.50, 95% CI=0.14–0.86, I²=58.9%]. After conducting the subgroup analysis and sensitive analysis, the results showed consistent significant association with the one based on all studies. No publication biases were found. Our analysis indicated that plasma or serum copper level in PE patients was significantly higher than that in healthy pregnancy women.

Serum copper and zinc levels in preeclamptic Nigerian women

Background:

The exact etiology of preeclampsia remains unknown even though several studies have been done. Some studies have shown that supplementation of zinc (Zn) and copper could ameliorate the effects of preeclampsia while other studies did not establish the beneficial role of these elements in preeclampsia. The objective of this study was to compare the Zn and copper levels in the serum of Nigerian women with or without preeclampsia.

Materials and Methods:

In this study, serum Zn and copper levels were determined using atomic absorption spectrometry in 54 patients and 48 healthy normotensive pregnant women. The mean, standard deviation, Student's t-test, and Pearson correlation were employed.

Results:

Serum Zn was significantly lower in patients than controls (8.27 ± 0.60 vs. 12.16 ± 1.83 μmol/l. P <0.001) (t-test). Serum copper was also significantly lower in patients than controls (8.14 ± 1.80 vs. 16.62 ± 3.17 μmol/l, P < 0.001).

Conclusion:

There was a significant reduction in the levels of Zn and copper in patients with preeclampsia. Dietary supplementation of these trace elements may help to prevent preeclampsia.

Dietary Calcium Intake, Serum Calcium Level, and their Association with Preeclampsia in Rural North India

Background:

Preeclampsia in pregnancy has been shown to be associated with low serum calcium level. Though the evidence is abundant, it is equivocal.

Objectives:

The study aimed to estimate the dietary calcium intake and serum calcium status among pregnant women, and to document the association of the dietary calcium intake and serum calcium status with incidence of preeclampsia in the 3rd trimester of pregnancy.

Materials and Methods:

A community-based cross-sectional study was conducted in the Health and Demographic Surveillance System (HDSS) site, Ballabgarh, Haryana, India. All pregnant women between 28 weeks and 36 weeks of gestation were interviewed. A semi-structured interview schedule and a 24-h dietary recall questionnaire were administered to assess the dietary calcium intake. AutoAnalyser (Biolis 24i) was used for measuring serum calcium.

Results:

We enrolled 217 pregnant women. The mean [standard deviation (SD)] dietary calcium intake was 858 (377) mg/day. The mean (SD) serum calcium level was 9.6 mg/dL (0.56). Incidence of preeclampsia was 13.4%. Preeclampsia was not associated with hypocalcemia [odds ratio (OR) = 1.2 95% confidence interval (CI); 0.27-3.98].

Conclusion:

The majority of pregnant women had inadequate dietary calcium intake. The prevalence of hypocalcemia was low. Low serum calcium level was not associated with preeclampsia. Calcium supplementation may not reduce preeclampsia in this population.

Comparison of Serum Calcium and Magnesium Between Preeclamptic and Normotensive Pregnant Nigerian Women in Abakaliki, Nigeria

Background:

Evidence suggests the involvement of calcium and magnesium metabolism in the pathophysiology of preeclampsia. However, findings from studies are heterogenous and inconsistent.

Aim:

The study aimed to compare the total serum calcium and magnesium levels in preeclamptic women with that of normotensive pregnant women.

Subjects and Methods:

A cross-sectional subjects of eighty pregnant women living in Abakaliki, Ebonyi state, South-East Nigeria, were recruited into the study. The present study compared serum calcium and magnesium in forty preeclamptic (cases) and forty normotensive (control) pregnant women matched for age, parity, and socioeconomic status. Serum calcium and magnesium levels were measured using atomic absorption spectrophotometer. Statistical analysis was done using SPSS Version 20 statistical software. Differences between means were compared using Student's t-test with P < 0.05 considered as statistically significant.

Results:

While the mean serum calcium was comparable between preeclamptic and normotensive pregnant women (13.99 [3.29] vs. 14.02 [5.68] μg/dl), the preeclamptic pregnant women have significantly (P < 0.001) lower serum magnesium in comparison to their normotensive counterparts (3.22 [1.05] vs. 4.15 [0.78]).

Conclusion:

It may be concluded that serum magnesium seems to play a crucial role in the pathophysiology of preeclampsia in this environment.