Correlation of Copper and Zinc in Spontaneous Abortion

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.

Trace element concentrations in blood samples from dairy cows with uterine torsion and their neonatal calves

Background and Aim

Mineral deficiencies can lead to dystocia and abnormalities in neonates. Stillbirth of neonatal calves in dairy cows due to dystocia has become an economic problem. Uterine torsion (UT) is a common form of dystocia observed in dairy cows. However, to the best of our knowledge, there have been no reports on the characteristics of serum trace element concentrations in dairy cows with UT. This study aimed to comprehensively measure serum trace element concentrations in dairy cows with UT and dystocia.

Materials and Methods

Dairy cows with (n = 15) and without (n = 27) UT and neonates (n = 9 and n = 26, respectively) were included in this study. Blood samples (10 mL) were collected, and serum trace element concentrations were evaluated using inductively coupled plasma mass spectrophotometry.

Results

The mortality rate at birth was significantly higher in calves delivered by cows with UT than those delivered by cows without UT. The odds ratio for mortality rate at birth in dairy cows with UT was 7.85. Serum zinc (Zn) levels were significantly lower in cows with UT than in cows without UT (p = 0.01). The copper: Zn ratio was significantly higher in cows with UT than in cows without torsion (p = 0.05). In contrast, serum Cobalt (Co) concentrations were significantly higher in neonates from cows with UT than in neonates from cows without UT (p = 0.01).

Conclusion

Uterine torsion is associated with a high mortality rate at birth and considerable economic losses. Cows with UT had low serum Zn levels, and neonates born to these cows had high serum Co levels.

Association between female circulating heavy metal concentration and abortion: a systematic review and meta-analysis

Objective

This study aimed to evaluate the association between blood heavy metal (zinc (Zn), copper (Cu), lead (Pb), and cadmium (Cd)) concentrations and spontaneous abortion (SA) and recurrent pregnancy loss (RPL) and explore the possible endocrine dysfunction associated with it.

Methods

A literature search was performed in the PubMed, Embase, Cochrane Library, and Web of Science databases up to April 2023. The overall effects were expressed as the standard mean difference (SMD). Subgroup analysis was performed according to the type of abortion (SA or RPL). Stata 16.0 was utilized for data analysis.

Results

Based on the integrated findings, abortion women showed significantly lower Zn (SMD = -1.05, 95% CI: -1.74 to -0.36, p = 0.003) and Cu concentrations (SMD = -1.42, 95% CI: -1.97 to -0.87, p <0.001) and higher Pb (SMD = 1.47, 95% CI: 0.89-2.05, p <0.001) and Cd concentrations (SMD = 1.15, 95% CI: 0.45-1.85, p = 0.001) than normal pregnant women. Subgroup analysis showed that Zn and Cu deficiency and Cd and Pb exposure were significantly (p <0.05) associated with RPL, whereas Cu deficiency and Cd and Pb exposure were significantly (p <0.05) associated with SA.

Conclusion

Zn and Cu deficiencies and Pb and Cd exposure were associated with abortion. Endocrine dysfunction, such as insulin resistance, vitamin D insufficiency, and abnormal thyroid and sex hormone concentrations, is thought to be involved in heavy metal-related abortion.

Environmental and occupational exposure of metals and female reproductive health

Untainted environment promotes health, but the last few decades experienced steep upsurge in environmental contaminants posing detrimental physiological impact. The responsible factors mainly include the exponential growth of human population, havoc rise in industrialization, poorly planned urbanization, and slapdash environment management. Environmental degradation can increase the likelihood of human exposure to heavy metals, resulting in health consequences such as reproductive problems. As a result, research into metal-induced causes of reproductive impairment at the genetic, epigenetic, and biochemical levels must be strengthened further. These metals impact upon the female reproduction at all strata of its regulation and functions, be it development, maturation, or endocrine functions, and are linked to an increase in the causes of infertility in women. Chronic exposures to the heavy metals may lead to breast cancer, endometriosis, endometrial cancer, menstrual disorders, and spontaneous abortions, as well as pre-term deliveries, stillbirths. For example, endometriosis, endometrial cancer, and spontaneous abortions are all caused by the metalloestrogen cadmium (Cd); lead (Pb) levels over a certain threshold can cause spontaneous abortion and have a teratogenic impact; toxic amounts of mercury (Hg) have an influence on the menstrual cycle, which can lead to infertility. Impact of environmental exposure to heavy metals on female fertility is therefore a well-known fact. Thus, the underlying mechanisms must be explained and periodically updated, given the growing evidence on the influence of increasing environmental heavy metal load on female fertility. The purpose of this review is to give a concise overview of how heavy metal affects female reproductive health.

MTHFR gene polymorphism and homocysteine levels in spontaneous abortion of pregnant women

OBJECTIVE

This research explored the expression of MTHFR gene polymorphism and homocysteine (Hcy) in spontaneous abortions in pregnant women.

METHODS

Eighty-two spontaneous abortion patients treated in our hospital were selected prospectively, and 82 age-matched healthy and normal delivery women were included. The peripheral venous blood of the two groups was obtained, and the differences between MTHFR gene polymorphism and Hcy levels were analyzed.

RESULTS

The Hcy levels in spontaneous abortion patients were higher than those in the healthy control group (P<0.05). In the common mutation (C677T) of MTHFR gene polymorphism, the distribution of MTHFRC677T (TT, CC, CT) genotyping of both groups was different, but the Hcy levels in the observation group were higher than those in the normal control group (P<0.05). In addition, logistic analysis manifested that the the Hcy levels were higher than normal and MTHFRC677T (TT) mutant was an independent risk factor for spontaneous abortion of pregnant women.

CONCLUSION

MTHFRC677T (TT) is associated with the occurrence of hyperhomocysteinemia, and its high expression often indicates that the risk of spontaneous abortion is greatly increased, which may provide a new research direction for maternal health.

The Impact of Early Pregnancy and Exposure to Tobacco Smoke on Blood Antioxidant Status and Copper, Zinc, Cadmium Concentration-A Pilot Study

The aim of the study was to evaluate the impact of early pregnancy and exposure to tobacco smoke on antioxidant status and copper, zinc, and cadmium concentrations in the blood of non-smoking and smoking, as well as non-pregnant or pregnant women. The study included 213 women. More specifically, 150 women in first trimester of pregnancy and 63 non-pregnant women. Women were divided into subgroups according to exposure to tobacco smoke. Pregnancy significant influences higher copper and lower zinc concentration in the serum, whereas exposure to tobacco smoke during pregnancy is mainly associated with an elevation in cadmium and zinc concentration. It seems that metallothionein, superoxide dismutase, and glutathione peroxidase are the important antioxidants during early pregnancy, when exposure to tobacco smoke occurs, whereas the pregnancy itself is associated with a higher concentration of metallothionein and activity of catalase. Both pregnancy in the first trimester and exposure to tobacco smoke decrease glutathione concentration. In addition, active and passive maternal smoking have a similarly negative effect on antioxidant status in the first trimester. Early pregnancy as well as exposure to tobacco smoke is associated with significant alteration in antioxidant status and copper, zinc, and cadmium concentration. Due to a small number of smoking subjects (11 cases of non-pregnant, active smokers and 14 pregnant active smokers), the obtained results should be treated as a pilot, and this should be considered for future studies.

Complementary and Alternative Medicine for Threatened Miscarriage: Advantages and Risks

Threatened miscarriage is one of the most common complications causing pregnancy loss, and it affects approximately 20% of confirmed pregnancies. More and more women are seeking treatment with complementary and alternative medicine (CAM) for this common complication, and it has been reported that women have had successful pregnancies after threatened miscarriage when being treated with CAM, which mainly includes Chinese herbal medicines, acupuncture, and nutritional supplements as well as psychological interventions and other approaches. However, many experts are concerned about the safety and adverse events of certain CAM approaches in women with threatened miscarriage. Therefore, this review focuses on the status of CAM for threatened miscarriage and presents the potential therapeutic efficacy and safety of CAM based on some clinical and experimental studies. We thus hope to provide some instructive suggestions for the application of CAM for treating threatened miscarriage in the future.

Definition and Multiple Factors of Recurrent Spontaneous Abortion

Recurrent spontaneous abortion (RSA) is usually defined as three or more spontaneous abortions prior to 20-28 weeks gestation. RSA affects approximately 2-5% of all women of childbearing age, and it brings tremendous psychological and psychiatric trauma to the women and also results in economic burden. The causes could be female age, anatomical and chromosomal abnormalities, genetic, endocrinological, placental anomalies, infection, smoking and alcohol consumption, psychological factor, exposure to environmental factors such as heavy metal, environment pollution, and radiation.

The Role of Fe, Zn, and Cu in Pregnancy

Iron (Fe), copper (Cu), and zinc (Zn) are microelements essential for the proper functioning of living organisms. These elements participatein many processes, including cellular metabolism and antioxidant and anti-inflammatory defenses, and also influence enzyme activity, regulate gene expression, and take part in protein synthesis. Fe, Cu, and Zn have a significant impact on the health of pregnant women and in the development of the fetus, as well as on the health of the newborn. A proper concentration of these elements in the body of women during pregnancy reduces the risk of complications such as anemia, induced hypertension, low birth weight, preeclampsia, and postnatal complications. The interactions between Fe, Cu, and Zn influence their availability due to their similar physicochemical properties. This most often occurs during intestinal absorption, where metal ions compete for binding sites with transport compounds. Additionally, the relationships between these ions have a great influence on the course of reactions in the tissues, as well as on their excretion, which can be stimulated or delayed. This review aims to summarize reports on the influence of Fe, Cu, and Zn on the course of single and multiple pregnancies, and to discuss the interdependencies and mechanisms occurring between Fe, Cu, and Zn.