Increased homocysteine levels exist in women with preeclampsia from early pregnancy

Metabolic theory of preeclampsia: implications for maternal cardiovascular health

Preeclampsia (PE) is a multisystemic disorder of pregnancy that not only causes perinatal mortality and morbidity but also has a long-term toll on the maternal and fetal cardiovascular system. Women diagnosed with PE are at greater risk for the subsequent development of hypertension, ischemic heart disease, cardiomyopathy, cerebral edema, seizures, and end-stage renal disease. Although PE is considered heterogeneous, inefficient extravillous trophoblast (EVT) migration leading to deficient spiral artery remodeling and increased uteroplacental vascular resistance is the likely initiation of the disease. The principal pathophysiology is placental hypoxia, causing subsequent oxidative stress, leading to mitochondrial dysfunction, mitophagy, and immunological imbalance. The damage imposed on the placenta in turn results in the "stress response" categorized by the dysfunctional release of vasoactive components including oxidative stressors, proinflammatory factors, and cytokines into the maternal circulation. These bioactive factors have deleterious effects on systemic endothelial cells and coagulation leading to generalized vascular dysfunction and hypercoagulability. A better understanding of these metabolic factors may lead to novel therapeutic approaches to prevent and treat this multisystemic disorder. In this review, we connect the hypoxic-oxidative stress and inflammation involved in the pathophysiology of PE to the resulting persistent cardiovascular complications in patients with preeclampsia.

High Homocysteine Levels During Pregnancy and Its Association With Placenta-Mediated Complications: A Scoping Review

There is already abundant corroboration indicating that elevated serum homocysteine levels may be related to the risk of coronary, cerebral, and peripheral arterial diseases. High homocysteine levels have often been associated with placental vasculopathies and complications related to the placenta, such as fetal growth restriction, Abruption, hypertensive disorders of pregnancy, and recurrent abortions. This scoping review aims to integrate the currently available scientific literature and fill the gaps in our understanding of homocysteine metabolism during pregnancy and its relationship to placenta-mediated complications. Moreover, to summarize the existing literature on the correlation between raised maternal homocysteine levels in early gestation and its association with placenta-mediated complications. We developed this scoping review article by performing a literature review as per the Preferred Reporting Items for Systematic reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) guidelines and the search was conducted using PRISMA-S (an extension to PRISMA focusing on reporting the search components of systematic reviews) guidelines. The research question was clarified and modified using keywords with important literature published online between 2010 and 2022, which were included from PubMed, and Google Scholar databases with recognized titles and abstracts were examined and cross-checked for case overlap to choose the original reports. A summary of the descriptive data was organized according to the clinical manifestations (symptoms, imaging, and laboratory results) and outcomes (maternal and perinatal). In conclusion, a review of research papers from 2010 to 2022 showed that homocysteine levels during pregnancy fluctuate and are probably influenced by a population's regional, cultural, and socioeconomic status. According to the data, there is an association between elevated homocysteine levels and complications of pregnancies, such as early spontaneous abortions, pre-eclampsia, fetal development restriction, and abruption, as well as in certain cases of maternal and fetal mortality.

The Association Between Serum Homocysteine Levels and Placenta-Mediated Complications: A Narrative Review

The most extremely unfavourable outcome of pregnancy is the death of the mother and newborn. Negative outcomes for mothers or babies can occur as a result of complications or issues during pregnancy, birth or the post-partum period. Early elevated maternal homocysteine (Hct) levels during pregnancy have been linked to altered placental development. There is evidence that suggests an elevated maternal blood Hct level is the new obstetrical risk factor, and the association between hyperhomocysteinemia (HHct) and numerous obstetrical problems was recently recognised. Hct is an essential amino acid, which contains sulphur and is formed from the metabolism of methionine. HHct has several known aetiologies, including genetic anomalies; a deficiency in folic acid, vitamin B6 and vitamin B12; hypothyroidism; old age; and renal illnesses. Vascular problems, coronary artery disease, atherosclerosis and embolic illnesses can all occur as a result of high blood levels of Hct. Hct levels are lower in normal pregnancies than it is in women who are not pregnant. Many pregnancy-related problems, including pre-eclampsia (PE), recurrent pregnancy loss (RPL), placental abruption, premature delivery and foetal growth restriction (FGR) have been connected to HHct in recent research. We looked for pertinent literature using a thorough and systematic search from PubMed, Medline, Embase, Cochrane Library, Google, etc., and articles that were published before August 2022 based on serum Hct levels and various placenta-mediated complications for this review. In this review, we described the synthesis and metabolism of Hct in humans, Hct levels at various phases of normal pregnancy and the association between Hct and placenta-mediated pregnancy complications. The outcomes discovered can help obstetricians increase the likelihood of a successful pregnancy in cases where placenta-mediated issues are present. Lowering Hct levels with a high dose of folic acid tablets during the subsequent pregnancy may be useful for women who experienced these difficulties in prior pregnancies as a result of HHct.

Homocysteine metabolism as the target for predictive medical approach, disease prevention, prognosis, and treatments tailored to the person

Homocysteine (Hcy) metabolism is crucial for regulating methionine availability, protein homeostasis, and DNA-methylation presenting, therefore, key pathways in post-genomic and epigenetic regulation mechanisms. Consequently, impaired Hcy metabolism leading to elevated concentrations of Hcy in the blood plasma (hyperhomocysteinemia) is linked to the overproduction of free radicals, induced oxidative stress, mitochondrial impairments, systemic inflammation and increased risks of eye disorders, coronary artery diseases, atherosclerosis, myocardial infarction, ischemic stroke, thrombotic events, cancer development and progression, osteoporosis, neurodegenerative disorders, pregnancy complications, delayed healing processes, and poor COVID-19 outcomes, among others. This review focuses on the homocysteine metabolism impairments relevant for various pathological conditions. Innovative strategies in the framework of 3P medicine consider Hcy metabolic pathways as the specific target for in vitro diagnostics, predictive medical approaches, cost-effective preventive measures, and optimized treatments tailored to the individualized patient profiles in primary, secondary, and tertiary care.

A Novel Review of Homocysteine and Pregnancy Complications

Homocysteine (Hct) is a substance produced in the metabolism of methionine. It is an essential type of amino acid gained from the daily diet. Methylenetetrahydrofolate reductase (MTHFR) gene mutation is related to elevated total homocysteine (tHct) expressions, in particular, among women with low folate intake. Hyperhomocysteinemia (HHct) is caused by numerous factors, such as genetic defects, lack of folic acid, vitamin B₆ and B₁₂ deficiency, hypothyroidism, drugs, aging, and renal dysfunction. Increased Hct in peripheral blood may lead to vascular illnesses, coronary artery dysfunction, atherosclerotic changes, and embolic diseases. Compared to nonpregnant women, the Hct level is lower in normal pregnancies. Recent studies have reported that HHct was associated with numerous pregnancy complications, including recurrent pregnancy loss (RPL), preeclampsia (PE), preterm delivery, placental abruption, fetal growth restriction (FGR), and gestational diabetes mellitus (GDM). Besides, it was discovered that neonatal birth weight and maternal Hct levels were negatively correlated. However, a number of these findings lack consistency. In this review, we summarized the metabolic process of Hct in the human body, the levels of Hct in different stages of normal pregnancy reported in previous studies, and the relationship between Hct and pregnancy complications. The work done is helpful for obstetricians to improve the likelihood of a positive outcome during pregnancy complications. Reducing the Hct level with a high dosage of folic acid supplements during the next pregnancy could be helpful for females who have suffered pregnancy complications due to HHct.

Maternal Hypertensive Disorders in Pregnancy and Postpartum Plasma B Vitamin and Homocysteine Profiles in a High-Risk Multiethnic U.S., Population

Background: Hypertensive disorders of pregnancy are a recognized risk factor of a woman's future cardiovascular risk. The potential role of micronutrients in mitigating hypertensive disorders is not fully understood. This study examined maternal postpartum plasma B vitamin profiles by hypertensive disorders of pregnancy in a high-risk multiethnic U.S. population. Materials and Methods: The analyses included 2584 mothers enrolled within 3 days postpartum at the Boston Medical Center. Hypertensive disorders of pregnancy included gestational hypertension and pre-eclampsia disorders (pre-eclampsia, eclampsia, hemolysis, elevated liver enzymes, and/or low platelets syndrome) as documented in the medical records. Plasma folate, vitamin B12, and homocysteine levels were measured in blood samples collected at enrollment. Kernel density plots and multivariable regressions were used to examine the relationship between hypertensive disorders and postpartum B vitamin profiles. Results: Of the 2584 mothers, 10% had pre-eclampsia disorders that were associated with significantly lower plasma folate (adjusted beta coefficient (aβ): -0.10; 95% CI: -0.22 to -0.06) and increased homocysteine (aβ: 0.08; 95% CI: 0.04-0.13), but not with vitamin B12 concentrations. These associations remained robust after adjusting for a range of pertinent covariables and were more pronounced in non-Hispanic Black women compared with other groups. However, gestational hypertension was not significantly associated with any postpartum biomarker. Conclusions: We found that pre-eclampsia disorders, but not gestational hypertension, was associated with lower folate and higher homocysteine levels postpartum, especially among Black mothers. This finding, if further confirmed, may have implications for postpartum care, including attention to maternal micronutrient status to reduce and prevent hypertensive disorders in pregnancy-associated consequences in subsequent pregnancies and lifespan. Registration date: July 25, 2017; Registry website: https://clinicaltrials.gov/ct2/show/NCT03228875.

Identification of High-Risk Pregnancies in a Remote Setting Using Ambulatory Blood Pressure: The MINDI Cohort

Background: Ambulatory blood pressure is a potential tool for early detection of complications during pregnancy, but its utility in impoverished settings has not been assessed. This cross-sectional study aimed to determine whether maternal infections, nutrient deficiencies and inflammation (MINDI) were associated with four measures of maternal blood pressure (BP) and to determine their association with symphysis-fundal-height (SFH). Methods: Environmental and dietary factors, intake of iron and a multiple-nutrient supplement (MNS), markers of inflammation, protein, anemia, folate, vitamins B₁₂, A and D status, and urogenital, skin, oral and intestinal nematode infections were measured in indigenous pregnant Panamanian women. Stepwise multiple linear and logistic regression models explored determinants of systolic and diastolic blood pressure (SBP, DBP), hypotension (SBP < 100 and DBP < 60), mean arterial pressure (MAP), elevated MAP (eMAP), and pulse pressure (PP). Associations of BP with intestinal nematodes and with SFH Z scores (≥16 wk) were also explored. Results: Despite absence of high SBP or DBP, 11.2% of women had eMAP. Furthermore, 24.1% had hypotension. Linear regression showed that hookworm infection was associated with higher SBP (P = 0.049), DBP (P = 0.046), and MAP (P = 0.016), whereas Ascaris was associated with lower DBP (P = 0.018) and MAP (P = 0.028). Trichomonas was also associated with lower SBP (P < 0.0001) and MAP (P = 0.009). The presence of Trichuris (OR: 6.7, 95% CI 1.0-44.5) and folic acid deficiency (OR: 6.9, 95% CI 1.4-33.8) were associated with increased odds of eMAP. The odds of low BP was higher in the presence of Ascaris (OR: 3.63 ± 2.28, P = 0.040), but odds were lowered by MNS (OR: 0.35 ± 0.11, P = 0.001), more intake of animal-source foods/wk (OR: 0.7, 95% CI 0.5-0.9) and by higher concentrations of IL-17 (OR: 0.87 ± 0.05, P = 0.016). Conclusion: MINDI were bi-directionally associated with blood pressure indicators. In this MINDI cohort, infections, nutrients and cytokines both raised, and lowered BP indices. The presence of eMAP identified pregnant women at risk of hypertension whereas low PP was associated with lower SFH. Therefore, MAP and PP may help in detecting women at risk of adverse pregnancy outcomes in settings with limited access to technology.

The REVAMP study: research exploring various aspects and mechanisms in preeclampsia: study protocol

Background

Preeclampsia is a major cause of maternal, fetal and neonatal morbidity and mortality, particularly in developing countries. Considering the burden of preeclampsia and its associated complications, it is important to understand the underlying risk factors and mechanisms involved in its etiology. There is considerable interest in the potential for dietary long chain polyunsaturated fatty acids (LCPUFA) as a therapeutic intervention to prevent preeclampsia, as they are involved in angiogenesis, oxidative stress, and inflammatory pathways.

Methods

The REVAMP study (Research Exploring Various Aspects and Mechanisms in Preeclampsia) follows a cohort of pregnant women from early pregnancy until delivery to examine longitudinally the associations of maternal LCPUFA with clinical outcome in preeclampsia. A multisite centre for advanced research was established and pregnant women coming to Bharati hospital and Gupte hospital, Pune, India for their first antenatal visit are recruited and followed up at 11–14 weeks, 18–22 weeks, 26–28 weeks, and at delivery. Their personal, obstetric, clinical, and family history are recorded. Anthropometric measures (height, weight), food frequency questionnaire (FFQ), physical activity, socioeconomic status, fetal ultrasonography, and color Doppler measures are recorded at different time points across gestation. Maternal blood at all time points, cord blood, and placenta at delivery are collected, processed and stored at − 80 °C. The children’s anthropometry is assessed serially up to the age of 2 years, when their neurodevelopmental scores will be assessed.

Discussion

This study will help in early identification of pregnant women who are at risk of developing preeclampsia. The prospective design of the study for the first time will establish the role of LCPUFA in understanding the underlying biochemical and molecular mechanisms involved in preeclampsia and their association with developmental programming in children.

The Role of Nitric Oxide, ADMA, and Homocysteine in The Etiopathogenesis of Preeclampsia-Review

Preeclampsia is a serious, pregnancy-specific, multi-organ disease process of compound aetiology. It affects 3–6% of expecting mothers worldwide and it persists as a leading cause of maternal and foetal morbidity and mortality. In fact, hallmark features of preeclampsia (PE) result from vessel involvement and demonstrate maternal endothelium as a target tissue. Growing evidence suggests that chronic placental hypoperfusion triggers the production and release of certain agents that are responsible for endothelial activation and injury. In this review, we will present the latest findings on the role of nitric oxide, asymmetric dimethylarginine (ADMA), and homocysteine in the etiopathogenesis of preeclampsia and their possible clinical implications.

Methylenetetrahydrofolate Reductase Enzyme Level and Antioxidant Activity in Women with Gestational Hypertension and Pre-eclampsia in Lagos, Nigeria

Background

Deficiencies of enzymes in the folate cycle may lead to the generation of homocysteine, a toxic metabolic intermediate with pro-oxidant effect and ability to induce oxidant stress and lipid peroxidation as part of the pathophysiological process in gestational hypertension (GH) and pre-eclampsia (PE).

Aim

The aim of this study is to assess the reliability of plasma homocysteine (hcy) 5, 10 methylenetetrahydrofolate reductase (MTHFR) enzyme and oxidative stress parameters as indicators of aetio-pathogenesis and severity of gestational hypertension and pre-eclampsia.

Subjects and Methods

This was a comparative cross-sectional study conducted over 6 months. Two hundred pregnant women were recruited from two sites. They were divided into gestation hypertension (n = 40), pre-eclampsia (n = 60) and control groups (n = 100). Parameters evaluated for statistical analysis were MTHFR enzyme level, plasma homocysteine and malondialdehyde (MDA) levels, with glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) activities.

Results

Mean plasma hcy level and MDA were significantly higher in pre-eclampsia and gestational hypertension when compared to control group (p < 0.05). However, MTHFR enzyme level, GSH, SOD and CAT were significantly higher in normotensive females when compared to PE and GH subgroups (p < 0.05). Pre-eclampsia was significantly associated with an increased risk of lipid peroxidation (OR = 4.923; p = 0.007).

Conclusion

Pre-eclampsia and gestational hypertension are associated with marked homocysteine metabolic derangement and increased lipid peroxidation induced by oxidative stress and reduced MTHFR enzyme activity which may be the significant risk factors in the aetio-pathogenesis of GH and PE.

The role of maternal homocysteine concentration in placenta-mediated complications: findings from the Ottawa and Kingston birth cohort

Background

Homocysteine is an intermediate metabolite implicated in the risk of placenta-mediated complications, including preeclampsia, placental abruption, fetal growth restriction, and pregnancy loss. Large cohort and case-control studies have reported inconsistent associations between homocysteine and these complications. The purpose of this study was to investigate whether elevated maternal plasma homocysteine concentration in the early to mid-second trimester is associated with an increased risk of placenta-mediated complications. We examined the following potential moderating factors that may explain discrepancies among previous studies: high-risk pregnancy and the MTHFR 677C>T polymorphism.

Methods

We analyzed data from participants recruited to the Ottawa and Kingston (OaK) Birth Cohort from 2002 to 2009 in Ottawa and Kingston, Canada. The primary outcome was a composite of any placenta-mediated complication, defined as a composite of small for gestational age (SGA) infant, preeclampsia, placental abruption, and pregnancy loss. Secondary outcomes were, individually: SGA infant, preeclampsia, placental abruption, and pregnancy loss. We conducted multivariable logistic regression analyses with homocysteine as the primary continuous exposure, adjusting for gestational age at the time of bloodwork and explanatory maternal characteristics. The functional form, i.e., the shape of the homocysteine association with the outcome was examined using restricted cubic splines and information criteria (Akaike’s/Bayesian Information Criterion statistics). Missing data were handled with multiple imputation.

Results

7587 cohort participants were included in the study. Maternal plasma homocysteine concentration was significantly associated (linearly) with an increased risk of both the composite outcome of any placenta-mediated complication (p = 0.0007), SGA (p = 0.0010), severe SGA, and marginally with severe preeclampsia, but not preeclampsia, placental abruption and pregnancy loss. An increase in homocysteine concentration significantly increased the odds of any placenta-mediated complication (odds ratio (OR) for a 5 μmol/L increase: 1.63, 95% Confidence Interval (CI) 1.23–2.16) and SGA (OR 1.76, 95% CI 1.25–2.46). Subgroup analyses indicated some potential for modifying effects of the MTHFR 677C>T genotype and high-risk pregnancy, although the interaction was not statistically significant (high-risk subgroup OR 2.37, 95% CI 1.24–4.53, p-value for interaction =0.14).

Conclusions

Our results suggest an independent effect of early to mid-pregnancy elevated maternal homocysteine on placenta-mediated pregnancy complications.

Electronic supplementary material

The online version of this article (10.1186/s12884-019-2219-5) contains supplementary material, which is available to authorized users.

Higher maternal plasma folate, vitamin B12 and homocysteine levels in women with preeclampsia

Micronutrients like vitamin B₁₂ and folate play an important role in nucleic acid metabolism, cell growth, and are important determinants of fetal growth. The present study examined the levels of maternal and cord plasma folate, vitamin B₁₂, homocysteine, and their association with birth outcome in women with preeclampsia (PE). This study includes 450 normotensive control (NC) and 350 women with PE. PE women were further classified into women delivering at term (n = 224) and preterm (n = 126). Maternal and cord blood was collected at delivery. The levels of maternal vitamin B₁₂ (p < 0.05), folate (p < 0.01), and homocysteine (p < 0.01) were higher in the PE group as compared to the NC group. Maternal folate levels were higher in both term and preterm groups, while vitamin B₁₂ levels were higher only in the preterm group as compared to NC group. In contrast, homocysteine was higher only in the term PE group. Similar changes were also observed in the cord plasma. There was a positive association of maternal plasma homocysteine with systolic (r = 0.151, p = 0.000, n = 578) and diastolic blood pressure (r = 0.213, p = 0.000, n = 578) in the whole cohort. A negative association of maternal folate with systolic blood pressure (r = -0.105, p = 0.048, n = 352) while a positive association with baby weight in the NC group (r = 0.116, p = 0.029, n = 352). The present study suggests that maternal and cord micronutrient levels are altered in women with PE.

Correlation of Maternal Serum Homocysteine in the First Trimester with the Development of Gestational Hypertension and Preeclampsia

Background

This study investigated the relationship of serum homocysteine in early pregnancy with the risk of gestational hypertension (GH) and preeclampsia (PE) and with the severity of preeclampsia.

Material/Methods

In a retrospective cohort study, we identified 147 confirmed cases of preeclampsia (103 with mild PE and 44 with severe PE) and 147 confirmed cases of GH; 4418 women who remained normotensive and nonproteinuric throughout pregnancy served as controls. Maternal blood samples were collected at between 11 and 13 weeks of gestation to test serum concentrations of homocysteine (Hcy), folic acid, and VitB12. A logistic regression model was used to calculate adjusted odds ratios (aORs) and 95% confidence intervals (CIs).

Results

Women who subsequently developed GH and PE were older and had higher body mass indexes (BMIs) than those in the control group. Compared with the control group, women who developed PE were less educated (P=0.031), and more of those who developed GH were primiparas (P=0.012). The serum levels of Hcy in severe PE were significantly higher than those in the control group (median: 8.50 μmol/L vs. 7.33 μmol/L, P<0.001). After logistic regression analyses for potential confounding factors, the adjusted odds ratios (aORs) of Hcy was 1.12 for severe PE (95% CI 1.06–1.20). The serum concentrations of folic acid and VitB12 in those with GH and PE were not significantly different from controls.

Conclusions

A high level of Hcy in the first trimester is an independent risk factor for severe PE, although it is not a useful marker for the subsequent development of GH and mild PE.

Associations of Maternal Vitamin B12 Concentration in Pregnancy With the Risks of Preterm Birth and Low Birth Weight: A Systematic Review and Meta-Analysis of Individual Participant Data

Vitamin B12 (hereafter referred to as B12) deficiency in pregnancy is prevalent and has been associated with both lower birth weight (birth weight <2,500 g) and preterm birth (length of gestation <37 weeks). Nevertheless, current evidence is contradictory. We performed a systematic review and a meta-analysis of individual participant data to evaluate the associations of maternal serum or plasma B12 concentrations in pregnancy with offspring birth weight and length of gestation. Twenty-two eligible studies were identified (11,993 observations). Eighteen studies were included in the meta-analysis (11,216 observations). No linear association was observed between maternal B12 levels in pregnancy and birth weight, but B12 deficiency (<148 pmol/L) was associated with a higher risk of low birth weight in newborns (adjusted risk ratio = 1.15, 95% confidence interval (CI): 1.01, 1.31). There was a linear association between maternal levels of B12 and preterm birth (per each 1-standard-deviation increase in B12, adjusted risk ratio = 0.89, 95% CI: 0.82, 0.97). Accordingly, B12 deficiency was associated with a higher risk of preterm birth (adjusted risk ratio = 1.21, 95% CI: 0.99, 1.49). This finding supports the need for randomized controlled trials of vitamin B12 supplementation in pregnancy.

The evaluation of serum homocysteine, folic acid, and vitamin B12 in patients complicated with preeclampsia

Introduction

Increased plasma homocysteine may be associated with adverse pregnancy outcomes, such as preeclampsia. The aim of this study was to determine the plasma homocysteine, serum folate, and vitamin B12 levels in preeclamptic pregnant women.

Methods

This case-control study was conducted in 2016 in Ahwaz on 51 pregnant women with preeclampsia and 51 healthy pregnant women of the same gestational age, who served as controls. The case group also was subdivided into severe and non-severe preeclampsia. Patients’ data were collected through a questionnaire and medical records. Serum homocysteine, folic acid, and vitamin B12 were analyzed using chemiluminescent assay. The results were compared between two groups. Statistical analyses were done using IBM-SPSS 20.0. A Kolmogorov-Smirnov test, independent samples t-test, Mann-Whitney test, and Chi-square test were used for data analysis.

Results

No different demographic characteristics were found among the groups. Pregnant women complicated with preeclampsia displayed significantly higher serum homocysteine levels (p < 0.001) and lower serum folate (p = 0.005) and vitamin B12 levels (p < 0.001) compared to controls. A statistically significant inverse correlation was evident between serum homocysteine and serum folate levels in preeclamptic patients (p = 0.005; r = −0.389). In addition, an inverse correlation was identified between homocysteine and serum vitamin B12, but it was not statistically significant (p = 0.160; r = −0.200). Significant differences occurred in serum homocysteine and folate levels between the severe and non-severe subgroups (p < 0.001, p < 0.001).

Conclusion

Women complicated with preeclampsia displayed higher maternal serum homocysteine and lower serum folate and vitamin B12. Further studies are needed to confirm if the prescription of folic acid and vitamin B12 in women with a deficiency of these vitamins could decrease the level of serum homocysteine and, therefore, reduce the risk of preeclampsia or, if it occurred, its severity.