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

Associations of maternal blood metal concentrations with plasma eicosanoids among pregnant women in Puerto Rico

BACKGROUND/AIM

Heavy metals are known to induce oxidative stress and inflammation, and the association between metal exposure and adverse birth outcomes is well established. However, there lacks research on biomarker profiles linking metal exposures and adverse birth outcomes. Eicosanoids are lipid molecules that regulate inflammation in the body, and there is growing evidence that suggests associations between plasma eicosanoids and pregnancy outcomes. Eicosanoids may aid our understanding of etiologic birth pathways. Here, we assessed associations between maternal blood metal concentrations with eicosanoid profiles among 654 pregnant women in the Puerto Rico PROTECT birth cohort.

METHODS

We measured concentrations of 11 metals in whole blood collected at median 18 and 26 weeks of pregnancy, and eicosanoid profiles measured in plasma collected at median 26 weeks. Multivariable linear models were used to regress eicosanoids on metals concentrations. Effect modification by infant sex was explored using interaction terms.

RESULTS

A total of 55 eicosanoids were profiled. Notably, 12-oxoeicosatetraenoic acid (12-oxoETE) and 15-oxoeicosatetraenoic acid (15-oxoETE), both of which exert inflammatory activities, had the greatest number of significant associations with metal concentrations. These eicosanoids were associated with increased concentrations of Cu, Mn, and Zn, and decreased concentrations of Cd, Co, Ni, and Pb, with the strongest effect sizes observed for 12-oxoETE and Pb (β:-33.5,95 %CI:-42.9,-22.6) and 15-oxoETE and Sn (β:43.2,95 %CI:11.4,84.1). Also, we observed differences in metals-eicosanoid associations by infant sex. Particularly, Cs and Mn had the most infant sex-specific significant associations with eicosanoids, which were primarily driven by female fetuses. All significant sex-specific associations with Cs were inverse among females, while significant sex-specific associations with Mn among females were positive within the cyclooxygenase group but inverse among the lipoxygenase group.

CONCLUSION

Certain metals were significantly associated with eicosanoids that are responsible for regulating inflammatory responses. Eicosanoid-metal associations may suggest a role for eicosanoids in mediating metal-induced adverse birth outcomes.

Comparison of zinc levels in mothers with and without abortion: A systematic review and meta-analysiss

Introduction

Zinc is an essential trace element involved in different physiological functions. During pregnancy, it plays a crucial role in healthy embryogenesis. Abortion is the most severe problem associated with early pregnancy complications. This study aims to compare the levels of Zn in mothers with and without abortion.

Methods

This study is a systematic review and meta-analysis of studies published between 1980 and 2022 in PubMed, Science Direct, Pro Quest, Wiley, Web of Science, and Scopus databases. The search was conducted using both main and Mesh keywords, specifically targeting terms related to abortion, pregnancy loss, and zinc. Heterogeneity in the studies included in the meta-analysis was evaluated using statistical tests such as the chi-square test, I2, and forest plots. Publication bias was assessed using Begg's and Egger's tests. All analyses were conducted using Stata 15, and statistical significance was considered at p < 0.05.

Results

In general, nine studies were included in this analysis. Based on the results of the meta-analysis, the mean difference in the Zn level between mothers with and without abortion is equal to 193.18 (95 % CI; 107.11 to 279.25, P ≤ 0.001). In other words, the level of Zn in the group of mothers without abortion is 193 units higher than the group of mothers with abortion. The investigation into the comparison of Zn levels in mothers with and without abortion did not reveal any indication of publication bias according to both Begg's test (P-value = 0.858) and Egger's test (P-value = 0.270).

Conclusion

the study findings indicate a significant association between lower levels of Zn in mothers with abortion compared to mothers without abortion. This suggests that a higher level of Zn may have a preventive effect on the occurrence of abortion in pregnant women. The data also highlights the positive role of trace metals, particularly Zn, in influencing pregnancy outcomes and suggests that maintaining adequate levels of Zn may reduce the likelihood of abortion occurrence, along with other contributing factors. It is important to note that further research, including prospective cohort and experimental studies, is needed to provide more substantial evidence and strengthen these findings.

Prenatal metal exposures and childhood gut microbial signatures are associated with depression score in late childhood

BACKGROUND

Childhood depression is a major public health issue worldwide. Previous studies have linked both prenatal metal exposures and the gut microbiome to depression in children. However, few, if any, have studied their interacting effect in specific subgroups of children.

OBJECTIVES

Using an interpretable machine-learning method, this study investigates whether children with specific combinations of prenatal metals and childhood microbial signatures (cliques or groups of metals and microbes) were more likely to have higher depression scores at 9-11 years of age.

METHODS

We leveraged data from a well-characterized pediatric longitudinal birth cohort in Mexico City and its microbiome substudy (n = 112). Eleven metal exposures were measured in maternal whole blood samples in the second and third trimesters of pregnancy. The gut microbial abundances were measured at 9-11-year-olds using shotgun metagenomic sequencing. Depression symptoms were assessed using the Child Depression Index (CDI) t-scores at 9-11 years of age. We used Microbial and Chemical Exposure Analysis (MiCxA), which combines interpretable machine-learning into a regression framework to identify and estimate joint associations of metal-microbial cliques in specific subgroups. Analyses were adjusted for relevant covariates.

RESULTS

We identified a subgroup of children (11.6 % of the sample) characterized by a four-component metal-microbial clique that had a significantly high depression score (15.4 % higher than the rest) in late childhood. This metal-microbial clique consisted of high Zinc in the second trimester, low Cobalt in the third trimester, a high abundance of Bacteroides fragilis, a high abundance of Faecalibacterium prausnitzii. All combinations of cliques (two-, three-, and four-components) were significantly associated with increased log-transformed t-scored CDI (β = 0.14, 95%CI = [0.05,0.23], P < 0.01 for the four-component clique).

SIGNIFICANCE

This study offers a new approach to chemical-microbial analysis and a novel demonstration that children with specific gut microbiome cliques and metal exposures during pregnancy may have a higher likelihood of elevated depression scores.

Exploring the Complex Interplay of Trace Elements and Their Association with the Risk of Development of Pre-eclampsia in Pregnancy: a Case-Control

Pre-eclampsia, a hypertensive disorder occurring during pregnancy, poses significant risks to maternal and fetal health worldwide. Despite extensive research, the precise cause of pre-eclampsia remains unknown. Recent studies have indicated that trace elements, essential minerals crucial for various biological processes, might be significant factors in the development of pre-eclampsia. This study examines the intricate relationship between trace elements (magnesium, copper, zinc, calcium, phosphorus, and iron) and the severity of pre-eclampsia. The study involves a total of 150 participants, categorized into three distinct groups: 50 individuals with mild pre-eclampsia, 50 with severe pre-eclampsia, and 50 healthy pregnant controls. Specifically, out of the 100 pre-eclampsia cases, 5 were identified as early-onset and 95 as late-onset. Participants were recruited from a tertiary care hospital based on stringent inclusion and exclusion criteria. All the trace elements were quantitatively measured by direct colorimetric method using the Beckman Coulter AU480 analyzer system (Beckman Coulter, USA). Pre-eclampsia cases exhibited a significantly lowered level of magnesium (2.02 mg/dL), zinc (57.62 mg/dL), calcium (8.02 mg/dL), and phosphorus (3.93 mg/dL). These levels were approximately 14.4%, 20.2%, 21.1%, and 22.6% lower when compared to healthy pregnant women. Conversely, copper (151.67 mg/dL) and iron (53 μg/dL) levels were significantly elevated in pre-eclampsia cases. Age emerged as a significant risk factor, correlating with heightened pre-eclampsia susceptibility. Magnesium showed a protective effect, correlating negatively with age and positively with gestational age. The complex relationships between trace elements, age, and pre-eclampsia underline the need for personalized interventions, potentially including magnesium supplementation, in high-risk pregnancies.

Micronutrients in Food Supplements for Pregnant Women: European Health Claims Assessment

Micronutrients play a critical role in pregnant women, a vulnerable group with higher nutritional requirements. The first strategy to achieve adequate micronutrients intake should always be through a healthy and balanced diet. In the case where the diet is not enough to meet these requirements, food supplements should be prescribed under supervision to complement the diet, and these products must bear reliable information about the declared nutritional contents and health benefits. Based on the data provided by the Coordinated System of Fast Interchange of Information (SCIRI) and to know the current national situation, this work addresses the assessment of the content and the adequacy of health claims related to some micronutrients (vitamin C, vitamin B9, iron, copper, manganese, zinc, calcium, magnesium) contained in food supplements for pregnant women commercialized in Spain. Analytical results coincided with the declared values and were covered by the ranges of tolerances, and samples met the requirements to use health claims. Although the samples could even include more claims, manufacturers could have selected those which either best addressed pregnant women's conditions or best aligned with marketing intentions. This study confirms an adequate use of health claims in food supplement samples, which could be interesting for strengthening consumers' confidence in the benefits shown in the labeling and for encouraging the use of health claims as a useful tool for making better-informed purchasing decisions.

The Effect of Pumpkin Seed Biscuits on Nutritional and Zinc Status: A Randomized Controlled Trial in Pregnant Women

BACKGROUND: In several studies in Indonesia, low birth weight (LBW) is shown as the most dominant risk factor for stunting. Some of the causes of LBW are chronic energy deficiency during pregnancy, anemia during pregnancy, lack of nutrient supply during pregnancy, pregnancy complications, maternal parity, and birth spacing. In this case, women commonly suffer from micronutrient deficiencies including iodine, iron, Vitamin A, zinc, and folate. Related to this, about 80% of pregnant women in the world fulfill normative pregnancy needs due to inadequate zinc intake. One source of micronutrients rich in zinc is pumpkin seeds. The nutritional potential of pumpkin seeds is realized in the form of food products for pregnant women, including amino acids. One example of pumpkin seed fortification has been assessed in biscuit products by trained panelists and consumers, obtaining results that 20% additional pumpkin seed flour to biscuits becomes the best treatment. Meanwhile, in the case of this study, we expect that the pumpkin seed biscuits provided can increase the energy intake in pregnant women because when pumpkin seeds are added, the nutrition contained in the biscuits is also increased, in this case, the nutrition includes the zinc and Fe. AIM: The purpose this research is to figure out how pumpkin seed biscuits affect pregnant women concerning their nutrition status and serum zinc levels. METHODS: The method employed was a double-blind and randomized experimental research involving pre- and post-test control groups. The inclusion criteria of the participants involved were pregnant women aged 20–35 years old who were at their first and second trimesters of pregnancy and parity one to three and singleton pregnancy. Meanwhile, the exclusion criteria of the participants were pregnant women suffering from severe complications. There were 89 pregnant women further gathered in this study, but only 66 of them met the criteria and idled into two groups. In this case, one group received the pumpkin seed biscuit intervention, while the other received placebo biscuits. The intervention was conducted for 90 days where the pregnant women were provided with four biscuits for daily consumption. RESULTS: The nutritional status parameter of pregnant women involved in the current research was assessed, including body weight, mid-upper arm circumference (MUAC), and serum zinc levels. In this case, the average serum zinc level obtained was 48.75 g/dL from 60 pregnant women. Furthermore, a significant increase occurred in nutritional status for each group, marked by body weight gain, and increased MUAC. However, no significant difference emerged between the pumpkin seed biscuit group and the placebo biscuit group with p = 0.914 and p = 0.916, respectively. A significant increase in zinc levels was observed in both groups. In this case, changes in zinc levels between the two groups were significantly different (13.72 ± 1.84 vs. 9.81 ± 11.81, p = 0.007). CONCLUSION: Giving pumpkin seed biscuits contribute to weight gain and increase the MUAC the pregnant women which, in turn, improves their nutritional status and serum zinc.

Perinatal Origins of Adult Disease and Opportunities for Health Promotion: A Narrative Review

The “developmental origins of health and disease” (DOHaD) hypothesis refers to the influence of early developmental exposures and fetal growth on the risk of chronic diseases in later periods. During fetal and early postnatal life, cell differentiation and tissue formation are influenced by several factors. The interaction between genes and environment in prenatal and early postnatal periods appears to be critical for the onset of multiple diseases in adulthood. Important factors influencing this interaction include genetic predisposition, regulation of gene expression, and changes in microbiota. Premature birth and intrauterine growth restriction (IUGR) are other important factors considered by the DOHaD hypothesis. Preterm birth is associated with impaired or arrested structural or functional development of key organs/systems, making preterm infants vulnerable to cardiovascular, respiratory, and chronic renal diseases during adulthood. Growth restriction, defined as impaired fetal growth compared to expected biological potential in utero, is an additional negative factor increasing the risk of subsequent diseases. Environmental factors implicated in the developmental programming of diseases include exposure to pollution, stress, drugs, toxic agents, nutrition, and exercise. The DOHaD may explain numerous conditions, including cardiovascular, metabolic, respiratory, neuropsychiatric, and renal diseases. Potential antenatal and postnatal preventive measures, interventions, and future directions are discussed.

Zinc homeostasis in immunity and its association with preterm births

Preterm birth is among the most common adverse pregnancy outcomes and is the leading cause of neonatal mortality and morbidity. While trace elements are essential for humans, their specific roles in the prenatal period remain unexplored. Zinc, a ubiquitous element plays a pivotal role in protein synthesis, cell division, nucleic acid metabolism, apoptosis, ageing, reproduction, immunological as well as antioxidant defense mechanism. Although zinc quantities are very small in body tissue, it is involved in every conceivable biochemical pathway which is critical for the performance of various functions necessary to sustain life. Owing to the multifactorial role of zinc, it is not possible to attribute a certain zinc dependent mechanism in pre-term births. Although the effect of zinc deficiency on immunity, its impact on maternal function and health as well as its role in the developing foetus is well documented, much less attention has been given to the understanding of micronutrient zinc homeostasis in immunity and its association with preterm births. Despite extensive research, the pathway by which zinc regulates pregnancy outcomes as well as the function of immune cells in controlling the delivery status (term/ preterm) is still obscure. The present review aims to focus on the understanding of relationship of micronutrient zinc homeostasis in immunity and its association with preterm births.