The importance of genetic and environmental effects for pre-eclampsia and gestational hypertension: a family study

Association studies of vasoactive genes and preeclampsia in taiwan

BACKGROUND

Preeclampsia (PE) is a serious condition characterized by hypertension and proteinuria after 20 weeks of gestation. The exact cause of PE is unknown but may involve abnormalities in the renin-angiotensin-aldosterone system (RAAS) and endothelial nitric oxide synthase (eNOS). Genetic variations in angiotensinogen (AGT), angiotensin-converting enzyme (ACE), and eNOS genes have been associated with PE. This study aimed to investigate the potential of vasoactive-related gene polymorphisms as indicators of susceptibility to preeclampsia in Taiwanese women.

METHODS

A total of 109 women with severe PE and 150 controls from the Taiwanese population were genotyped for specific vasoactive gene polymorphisms, including M235T and T174M polymorphisms of AGT gene, insertion/deletion (I/D) polymorphism in ACE gene, and G894T (Glu298Asp) polymorphism and 27bp variable number of tandem repeats (VNTR 3/4/5) polymorphism of the eNOS gene. The association between genotype and disease was assessed using Chi-square tests.

RESULTS

The study found no significant differences in the M235T and T174M polymorphisms of AGT gene between the PE and control groups. However, haplotype frequencies for the M235T and T174M polymorphisms exhibited a significant association with PE. The genotype distributions of the I/D polymorphism of ACE gene showed a significant difference between PE and control groups. Additionally, no significant differences were detected in the polymorphisms of the eNOS gene between PE and control groups.

CONCLUSION

The findings of this study suggest that the AGT M235T-T174M haplotype and ACE insertion/deletion polymorphism may contribute to the development of preeclampsia and could serve as susceptibility markers for preeclampsia in Taiwanese women.

Association of MTHFR C677T and A1298C variants with preeclampsia risk and angiogenic imbalance in Tunisian women

Preeclampsia (PE) is a pregnancy-specific vascular disorder associated with endothelial dysfunction, hypertension, and proteinuria. The methylenetetrahydrofolate reductase (MTHFR) enzyme regulates essential cellular functions in pregnancy owing to its effects on folate metabolism and DNA methylation. Previous studies implicated the association of rs1801133 (C677T; Ala222Val) and rs1801131 (A1298C; Glu429Ala) in the MTHFR gene with PE in different ethnic groups, but with mixed outcomes.

METHODS

Study cases comprised 675 Tunisian pregnant women, of whom 350 PE presented with PE, and the remaining 325 normotensive women served as controls. Genotyping of C677T and A1298C variants was performed by real-time PCR.

RESULTS

There was no statistically significant difference in the minor allele frequencies of C677T and A1298C between preeclampsia cases and controls after adjusting for key covariates. In addition, the prevalence of MTHFR C677T and A1298C minor allele homozygote genotypes was significantly higher in PE cases. The association of 1298C/C, but not 677T/T, with PE persisted after adjusting for the main covariates. Carrying the (minor) 677T allele was associated with marginally higher BMI, significantly higher sFlt-1 serum levels, and median sFlt-1/PlGF ratio and sFlt-1/PlGF ratio ≥ 85. Setting the major allele homozygotes (C677/A1298) as a reference, haplotype analysis demonstrated a higher prevalence of C677/C1298 and T677/C1298 haplotypes (P = 0.03) in PE cases compared to controls, which persisted for C677/C1298, but not T677/C1298 after controlling for key covariates.

DISCUSSION

Our results support an association between MTHFR polymorphisms and increased risk of PE, and an imbalance of PE-associated sFLT-1/PlGF.

Trauma and Posttraumatic Stress Disorder as Important Risk Factors for Gestational Metabolic Dysfunction

Gestational metabolic diseases adversely impact the health of pregnant persons and their offspring. Pregnant persons of color are impacted disproportionately by gestational metabolic disease, highlighting the need to identify additional risk factors contributing to racial-ethnic pregnancy-related health disparities. Trauma exposure and posttraumatic stress disorder (PTSD) are associated with increased risk for cardiometabolic disorders in nonpregnant persons, making them important factors to consider when identifying contributors to gestational metabolic morbidity and mortality health disparities. Here, we review current literature investigating trauma exposure and posttraumatic stress disorder as psychosocial risk factors for gestational metabolic disorders, inclusive of gestational diabetes, low birth weight and fetal growth restriction, gestational hypertension, and preeclampsia. We also discuss the physiological mechanisms by which trauma and PTSD may contribute to gestational metabolic disorders. Ultimately, understanding the biological underpinnings of how trauma and PTSD, which disproportionately impact people of color, influence risk for gestational metabolic dysfunction is critical to developing therapeutic interventions that reduce complications arising from gestational metabolic disease. KEY POINTS: · Gestational metabolic diseases disproportionately impact the health of pregnant persons of color.. · Trauma and PTSD are associated with increased risk for cardiometabolic disorders in nonpregnant per.. · Trauma and PTSD impact physiological cardiometabolic mechanisms implicated in gestational metabolic..

Cadmium Associated Preeclampsia: A Systematic Literature Review of Pregnancy and Birth Outcomes

Preeclampsia (PE), caused by multiple factors, is one of the most serious complications of pregnancy. Cadmium (Cd) is a heavy metal environmental pollutant, reproductive toxicant, and endocrine disruptor, which can increase the risk of PE. Cd toxicity due to occupational, diet, and environmental factors has worsened the risk. Studies showed elevated Cd concentration in maternal blood and placenta of PE women. However, the implicit association between Cd associated PE is still not highlighted. We systematically reviewed Cd-associated PE and its effect on pregnancy and birth outcomes. Based on "Preferred reporting items for systematic reviews and meta-analyses (PRISMA)" guidelines, eighty-six studies were identified by PubMed, Web of Science (WOS), and Scopus databases. Publications were included until October 2023 and articles screened based on our inclusion criteria. Our study identified that the exposure of controlled and uncontrolled Cd induces PE, which negatively affects pregnancy and birth outcomes. Given the serious nature of this finding, Cd is a potential adverse agent that impacts pregnancy and future neonatal health. Further comprehensive studies covering the whole trimesters of pregnancy and neonatal developments are warranted. Data on the molecular mechanisms behind Cd-induced PE is also essential for potential preventive, diagnostic, or therapeutic targets.

Pregnancy complications and new-onset maternal autoimmune disease

BACKGROUND

Autoimmune diseases disproportionately impact women and female-specific aspects of reproduction are thought to play a role. We investigated the time-varying association between pregnancy complications and new-onset autoimmune disease in females during the reproductive and midlife years.

METHODS

We conducted a population-based cohort study of 1 704 553 singleton births to 1 072 445 females in Ontario, Canada (2002-17) with no pre-existing autoimmune disease. Pregnancy complications were preeclampsia, stillbirth, spontaneous preterm birth and severe small for gestational age (SGA). Royston-Parmar models were used to estimate the time-varying association between pregnancy complications and a composite of 25 autoimmune diseases from date of delivery to date of autoimmune disease diagnosis or censoring at death, loss of health insurance, or 31 March 2021. Models were adjusted for baseline socio-demographics, parity and comorbidities.

RESULTS

At 19 years (median = 10.9 years of follow-up), cumulative incidence of autoimmune disease was 3.1% in those with a pregnancy complication and 2.6% in those without complications. Adjusted hazard ratio (AHR) curves as a function of time since birth were generally L-shaped. Universally, risks were most elevated within the first 3 years after birth [at 1 year: preeclampsia AHR 1.22, 95% confidence interval (CI) 1.09-1.36; stillbirth AHR 1.36, 95% CI 0.99-1.85; spontaneous preterm birth AHR 1.30, 95% CI 1.18-1.44; severe SGA AHR 1.14, 95% CI 0.99-1.31] and plateaued but remained elevated thereafter.

CONCLUSIONS

Prior history of pregnancy complications may be an important female-specific risk factor to consider during clinical assessment of females for possible autoimmune disease to facilitate timely detection and treatment.

Hemostasis in Pre-Eclamptic Women and Their Offspring: Current Knowledge and Hemostasis Assessment with Viscoelastic Tests

Pre-eclampsia (PE) is a placenta-mediated disease and remains a major cause of maternal and neonatal mortality and morbidity. As PE develops, normal pregnancy's hypercoagulable balance is disrupted, leading to platelet hyperactivation, excessive pathological hypercoagulability, and perturbed fibrinolysis. This narrative review aims to summarize the current knowledge regarding hemostasis in PE compared with healthy gestation and the potential effects of maternal PE on neonatal hemostasis. Finally, it aims to discuss hemostasis assessments for normal pregnancies and PE, emphasizing the role of viscoelastic tests, namely, thromboelastography (TEG) and thromboelastometry (ROTEM), for monitoring PE-associated hemostatic alterations. The use of TEG/ROTEM for assessing the hemostatic profile of PE women has been little considered, even though conventional coagulation tests (CCTs) have not helped to monitor hemostasis in this population. Compared with normal pregnancy, TEG/ROTEM in PE reveals an excessive hypercoagulability analogous with the severity of the disease, characterized by higher-stability fibrin clots. The TEG/ROTEM parameters can reflect PE severity and may be used for monitoring and as predictive markers for the disease.

Bayesian linear mixed model with multiple random effects for family-based genetic studies

Motivation: Family-based study design is one of the popular designs used in genetic research, and the whole-genome sequencing data obtained from family-based studies offer many unique features for risk prediction studies. They can not only provide a more comprehensive view of many complex diseases, but also utilize information in the design to further improve the prediction accuracy. While promising, existing analytical methods often ignore the information embedded in the study design and overlook the predictive effects of rare variants, leading to a prediction model with sub-optimal performance. Results: We proposed a Bayesian linear mixed model for the prediction analysis of sequencing data obtained from family-based studies. Our method can not only capture predictive effects from both common and rare variants, but also easily accommodate various disease model assumptions. It uses information embedded in the study design to form surrogates, where the predictive effects from unmeasured/unknown genetic and environmental risk factors can be modelled. Through extensive simulation studies and the analysis of sequencing data obtained from the Michigan State University Twin Registry study, we have demonstrated that the proposed method outperforms commonly adopted techniques. Availability: R package is available at https://github.com/yhai943/FBLMM.

Machine-learning predictive model of pregnancy-induced hypertension in the first trimester

In the first trimester of pregnancy, accurately predicting the occurrence of pregnancy-induced hypertension (PIH) is important for both identifying high-risk women and adopting early intervention. In this study, we used four machine-learning models (LASSO logistic regression, random forest, backpropagation neural network, and support vector machines) to predict the occurrence of PIH in a prospective cohort. Candidate features for predicting the occurrence of middle and late PIH were acquired using a LASSO algorithm. The performance of predictive models was assessed using receiver operating characteristic analysis. Finally, a nomogram was established with the model scores, age, and nulliparity. Calibration, clinical usefulness, and internal validation were used to assess the performance of the nomogram. In the training set (2258 pregnant women), eleven candidate factors in the first trimester were significantly associated with the occurrence of PIH (P < 0.001 in the training set). Four models showed AUCs from 0.780 to 0.816 in the training set. For the validation set (939 pregnant women), AUCs varied from 0.516 to 0.795. The nomogram showed good discrimination, with an AUC of 0.847 (95% CI: 0.805-0.889) in the training set and 0.753 (95% CI: 0.653-0.853) in the validation set. Decision curve analysis suggested that the model was clinically useful. The model developed using LASSO logistic regression achieved the best performance in predicting the occurrence of PIH. The derived nomogram, which incorporates the model score and maternal risk factors, can be used to predict PIH in clinical practice. We develop a model with good performance for clinical prediction of PIH in the first trimester.

Pregnancy outcomes and disease phenotype of hypertensive disorders of pregnancy in singleton pregnancies after in vitro fertilization: a retrospective analysis of 1130 cases

BACKGROUND

Although in vitro fertilization (IVF) can increase the incidence of hypertensive disorders of pregnancy (HDP), the pregnancy outcomes and disease phenotype of HDP in singleton pregnancies conceived via IVF remain unclear.

METHODS

This retrospective cohort study enrolled 1130 singleton pregnancies with HDP from 2016 to 2020. According to the mode of conception, they were allocated into IVF (n = 102) and natural conception (NC) groups (n = 1028). All IVF pregnancies were subdivided into frozen embryo transfer (FET) group (n = 42) and fresh embryo transfer (ET) group (n = 60). Demographic data, pregnancy outcomes and disease phenotypes of HDP among the groups were compared. The risk factors for severe preeclampsia (PE) and early-onset PE were analyzed.

RESULTS

The incidences of early-onset PE (P<0.001), severe PE (P = 0.016), cesarean section (P<0.001) and preterm births (P = 0.003) in the IVF-HDP group were significantly higher than those in the NC-HDP group, and gestational age at diagnosis of HDP (P = 0.027) and gestational age at delivery (P = 0.004) were earlier and birthweight of the neonates (P = 0.033) were lower in the IVF group. In singleton pregnancies with HDP, IVF was associated with increased risks for both severe PE and early-onset PE (aOR 1.945, 95% CI 1.256, 3.014; and aOR 2.373, 95% CI 1.537, 3.663, respectively), as well as FET, family history of preeclampsia, intrahepatic cholestasis of pregnancy, gestational hypothyroidism and multiparity were associated with increased risks of severe PE and early-onset PE.

CONCLUSIONS

In singleton pregnancies with HDP, IVF was associated with an increased incidence of the disease phenotype (severe or early-onset PE), as well as an increased incidence of pregnancy outcomes related to severe PE and early-onset PE.

Determinants of pre-eclampsia among pregnant women attending antenatal care and delivery services at Bahir Dar public hospitals, northwest Ethiopia: A case-control study

Background and Aims

Pre-eclampsia (PE) is a pregnancy-related syndrome that occurs after 20 weeks of pregnancy. The current study was designed to evaluate the determinants of PE in pregnant women following antenatal and delivery services.

Methods

An institution-based case-control study was performed in governmental hospitals of Bahir Dar city. The data were collected using an interview-administered questionnaire and analyzed by SPSS version 20 software. Bivariate and multivariable logistic regression models were utilized for the analysis of variables. A p < 0.05 was used to declare the level of significance.

Results

In this study, the mean ages (in years) of cases and controls were 28.20 ± 5.66 and 27.52 ± 4.70, respectively. Factors such as: being primiparous (adjusted odds ratio [AOR]: 3.19 at 95% confidence interval [CI]: 1.71, 5.97), family history of hypertension (HTN) (AOR: 4.14 at 95% CI: 1.71, 10.05), previous history of PE (AOR: 7.97 at 95% CI: 2.42, 26.63), number of antenatal care (ANC) visits (AOR: 5.43 at 95% CI: 2.86, 10.33), not taking iron and folic acid supplement (AOR: 4.46 at 95% CI: 1.59, 12.48), body mass index ≥25 kg/m² (AOR: 3.47 at 95% CI: 1.78, 6.77), not consuming vegetables (AOR: 1.99 at 95% CI: 1.07, 3.69) and not consuming egg, milk and milk products (AOR: 3.00 at 95% CI: 1.47, 6.11) were the determinants of PE.

Conclusion

In this study, different determinants of PE were identified. Hence, special attention should be given for primiparous women, women having previous history of PE and family history of HTN. Moreover, nutritional counseling should be given for pregnant women during ANC visits. Besides, higher officials should design an appropriate strategy to increase the number of mothers to complete their ANC visits and to take iron and folic acid supplements. Furthermore, to verify the determinants of PE, community-based cohort studies are warranted.

Polygenic prediction of preeclampsia and gestational hypertension

Preeclampsia and gestational hypertension are common pregnancy complications associated with adverse maternal and child outcomes. Current tools for prediction, prevention and treatment are limited. Here we tested the association of maternal DNA sequence variants with preeclampsia in 20,064 cases and 703,117 control individuals and with gestational hypertension in 11,027 cases and 412,788 control individuals across discovery and follow-up cohorts using multi-ancestry meta-analysis. Altogether, we identified 18 independent loci associated with preeclampsia/eclampsia and/or gestational hypertension, 12 of which are new (for example, MTHFR-CLCN6, WNT3A, NPR3, PGR and RGL3), including two loci (PLCE1 and FURIN) identified in the multitrait analysis. Identified loci highlight the role of natriuretic peptide signaling, angiogenesis, renal glomerular function, trophoblast development and immune dysregulation. We derived genome-wide polygenic risk scores that predicted preeclampsia/eclampsia and gestational hypertension in external cohorts, independent of clinical risk factors, and reclassified eligibility for low-dose aspirin to prevent preeclampsia. Collectively, these findings provide mechanistic insights into the hypertensive disorders of pregnancy and have the potential to advance pregnancy risk stratification.

Familial aggregation of stillbirth: A pedigree analysis of a matched case-control study

OBJECTIVE

To determine whether stillbirth aggregates in families and quantify its familial risk using extended pedigrees.

DESIGN

State-wide matched case-control study.

SETTING

Utah, United States.

POPULATION

Stillbirth cases (n = 9404) and live birth controls (18 808) between 1978 and 2019.

METHODS

Using the Utah Population Database, a population-based genealogical resource linked with state fetal death and birth records, we identified high-risk pedigrees with excess familial aggregation of stillbirth using the Familial Standardised Incidence Ratio (FSIR). Stillbirth odds ratio (OR) for first-degree relatives (FDR), second-degree relatives (SDR) and third-degree relatives (TDR) of parents with a stillbirth (affected) and live birth (unaffected) were estimated using logistic regression models.

MAIN OUTCOME MEASURES

Familial aggregation estimated using FSIR, and stillbirth OR estimated for FDR, SDR and TDR of affected and unaffected parents using logistic regression models.

RESULTS

We identified 390 high-risk pedigrees with evidence for excess familial aggregation (FSIR ≥2.00; P-value <0.05). FDRs, SDRs and TDRs of affected parents had 1.14-fold (95% confidence interval [CI]: 1.04-1.26), 1.22-fold (95% CI 1.11-1.33) and 1.15-fold (95% CI 1.08-1.21) higher stillbirth odds compared with FDRs, SDRs and TDRs of unaffected parents, respectively. Parental sex-specific analyses showed male FDRs, SDRs and TDRs of affected fathers had 1.22-fold (95% CI 1.02-1.47), 1.38-fold (95% CI 1.17-1.62) and 1.17-fold (95% CI 1.05-1.30) higher stillbirth odds compared with those of unaffected fathers, respectively. FDRs, SDRs and TDRs of affected mothers had 1.12-fold (95% CI 0.98-1.28), 1.09-fold (95% CI 0.96-1.24) and 1.15-fold (95% CI 1.06-1.24) higher stillbirth odds compared with those of unaffected mothers, respectively.

CONCLUSIONS

We provide evidence for familial aggregation of stillbirth. Our findings warrant investigation into genes associated with stillbirth and underscore the need to design large-scale studies to determine the genetic architecture of stillbirth.

NPFFR2 gene compound heterozygous variants associated with preeclampsia identified by whole-exome sequencing

BACKGROUND

Preeclampsia (PE) is an idiopathic disorder of pregnancy. The exact cause of PE remains unknown. Emerging evidence indicates that the cause of PE is linked to genetic factors. Therefore, the aim of this study was to identify the susceptibility genes for PE.

METHODS

Nine families with severe PE were recruited. The whole-exome sequencing (WES) was performed on each family, and Sanger sequencing was used to identify the potential pathogenic genetic variants.

RESULTS

After a rigorous bioinformatics analysis, compound heterozygous variants in the NPFFR2 gene, NM_004885.2: c.601A > G, p.Met201Val and c.995C > T, p.Ala332Val were found in the No.4 pedigree. Bioinformatics analysis showed that these sites were highly conserved among several species and were predicted to be pathogenic variants according to multiple online mutational function prediction software packages. Due to the compound heterozygous variants of NPFFR2, more bonds are generated between mutant amino acids and spatial adjacent amino acids, which may lead to more stable active conformation of protein and not easy to be degraded.

CONCLUSIONS

We demonstrated for the first time that compound heterozygous variants of the NPFFR2 gene might be potentially associated with severe PE, the results of this study provide clinicians and researchers with a better understanding of the molecular mechanisms underlying severe PE in pregnant women.

Elevated Expression of miR-296 in Human Placentas and Serum Samples From Pregnancies With Preeclampsia

Background: Preeclampsia (PE) is a hypertensive disorder of pregnancy characterized by widespread maternal endothelial dysfunction. Although clinical signs subside following delivery, long-term risks associated with PE include hypertension, stroke, and cardiovascular disease. MicroRNAs (miRNAs) are emerging as critical regulators of biological function, and while alterations to the miRNAs have been described in the context of pregnancy and PE, the postpartum implications of PE on miRNA expression are unknown. In the present study, we aimed to determine the clinical performance of miR-296 in PE. Methods: First, the clinical information and outcomes of all the participants were collected and analyzed. Afterward, the miR-296 expressions in the serum samples from healthy pregnant women and women with PE at different periods were detected using quantitative real-time polymerase chain reaction (qRT-PCR). Then, the receive operation characteristic (ROC) curve was used to determine the diagnostic value of miR-296 in PE. Finally, the at-term placentals were collected, the expressions of miR-296 in different groups were compared at first blood collection and at delivery. Results: In this study, we found that miR-296 expression was significantly increased in the placenta samples from PE patients compared with that in healthy controls both in early onset group (EOPE, p < 0.01) and late onset group (LOPE, p < 0.01). Furthermore, results of ROC analysis showed miR-296 might be a putative biomarker for early onset preeclampsia and late onset preeclampsia diagnosis with an area under the curve (AUC) of 0.84 (95% confidence interval 0.75-0.92) and 0.85 (95% confidence interval 0.77-0.93). Last but not the least, the expressions of miR-296 were significantly increased (p < 0.05) in serum samples of EOPE and LOPE patients (p < 0.001), and serum and placental levels of the miR-296 was positively correlated for EOPE (r = 0.5574, p < 0.001) and LOPE (r = 0.6613, p < 0.001) patients, respectively. Meanwhile, compared with those at first blood collection, the expression of miR-296 in EOPE (p = 0.05) and LOPE (p = 0.01) were significantly decreased at delivery. Conclusion: miR-296 may function as a putative diagnostic biomarker for PE and contribute to identifying at-risk mothers in pregnancy.

Gestational Hypertensive Disorders and Maternal Breast Cancer Risk in a Nationwide Cohort of 40,720 Parous Women

BACKGROUND

Preeclampsia and gestational hypertension are hypothesized to be associated with reduced maternal breast cancer risk, but the epidemiologic evidence is inconclusive. Our objective was to examine associations between gestational hypertensive disorders and breast cancer in a nationwide cohort of women with a family history of breast cancer.

METHODS

Women ages 35-74 years who had a sister previously diagnosed with breast cancer, but had never had breast cancer themselves, were enrolled in the Sister Study from 2003 to 2009 (N = 50,884). At enrollment, participants reported diagnoses of eclampsia, preeclampsia, or gestational hypertension in each pregnancy. We used Cox proportional hazards models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between history of a gestational hypertensive disorder and incident invasive breast cancer or ductal carcinoma in situ among 40,720 parous women. We used age as the time scale and adjusted for birth cohort, race-ethnicity, and reproductive, socioeconomic, and behavioral factors. We examined effect measure modification by risk factors for gestational hypertensive disease and breast cancer and assessed possible etiologic heterogeneity across tumor characteristics.

RESULTS

The prevalence of gestational hypertensive disease was 12%. During follow-up (mean = 10.9 years), 3,198 eligible women self-reported a breast cancer diagnosis. History of a gestational hypertensive disorder was not associated with breast cancer risk (HR = 1.0; 95% CI = 0.90, 1.1). We did not observe clear evidence of effect measure modification or etiologic heterogeneity.

CONCLUSIONS

History of a gestational hypertensive disorder was not associated with breast cancer risk in a cohort of women with a first-degree family history of breast cancer.

Protein Network Analysis of Whole Exome Sequencing of Severe Preeclampsia

Preeclampsia is a hypertensive disorder of pregnancy, which complicates up to 15% of US deliveries. It is an idiopathic disorder associated with several different phenotypes. We sought to determine if the genetic architecture of preeclampsia can be described by clusters of patients with variants in genes in shared protein interaction networks. We performed a case-control study using whole exome sequencing on early onset preeclamptic mothers with severe clinical features and control mothers with uncomplicated pregnancies between 2016 and 2020. A total of 143 patients were enrolled, 61 women with early onset preeclampsia with severe features based on ACOG criteria, and 82 control women at term, matched for race and ethnicity. A network analysis and visualization tool, Proteinarium, was used to confirm there are clusters of patients with shared gene networks associated with severe preeclampsia. The majority of the sequenced patients appear in two significant clusters. We identified one case dominant and one control dominant cluster. Thirteen genes were unique to the case dominated cluster. Among these genes, LAMB2, PTK2, RAC1, QSOX1, FN1, and VCAM1 have known associations with the pathogenic mechanisms of preeclampsia. Using bioinformatic analysis, we were able to identify subsets of patients with shared protein interaction networks, thus confirming our hypothesis about the genetic architecture of preeclampsia.

Preeclampsia, Natural History, Genes, and miRNAs Associated with the Syndrome

Preeclampsia (PE) is a hypertensive disease that affects pregnant women after 20 weeks of gestation. This disease is associated with an important risk of maternal and fetal mortality. PE is described as a placental pathology because, after delivery, most women recover normal arterial pressure. Poor invasion of the spiral arteries is a phenomenon well described in PE; this leads to a hypoxic uterine bed and imbalance of antiangiogenic and proangiogenic factors in the uteroplacental region, which in turn triggers the disease phenotype. The causes of the pathology are unclear; nevertheless, numerous approaches, including next-generation sequencing, association, and case control and miRNA studies, have shed light on the genetic/molecular basis of PE. These studies help us better understand the disease to advance new treatment strategies.

Evaluation of epigenetic age calculators between preeclampsia and normotensive pregnancies in an Australian cohort

Advanced biological aging, as assessed through DNA methylation markers, is associated with several complex diseases. The associations between maternal DNA methylation age and preeclampsia (PE) have not been fully assessed. The aim of this study was to examine if increased maternal DNA methylation age (DNAmAge) was shown to be accelerated in women with PE when compared to women who had normotensive pregnancies. The case/control cohort available for study consisted of 166 women (89 with normotensive pregnancy, 77 with PE) recruited previously at the Royal Women’s Hospital in Melbourne, Australia. DNA methylation profiles were obtained using the Illumina EPIC Infinium array for analysis of genomic DNA isolated from whole blood. These profiles were used to calculate seven estimates of DNAmAge and included (1) Horvath, (2) Hannum, (3) Horvath Skin and Blood, (4) Wu, (5) PhenoAge, (6) telomere length and (7) GrimAge and its surrogate measures. Three measures of DNA methylation age acceleration were calculated for all seven measures using linear regression. Pearson's correlation was performed to investigate associations between chronological age and DNAmAge. Differences between chronological age and DNAmAge and epigenetic age acceleration were investigated using t-tests. No significant difference was observed for chronological age between women with PE (age = 30.53 ± 5.68) and women who had normotensive pregnancies (age = 31.76 ± 4.76). All seven DNAmAge measures were significantly correlated (p < 0.001) with chronological age. After accounting for multiple testing and investigating differences in DNAmAge between normotensive women and women with PE, only Wu DNAmAge was significant (p = 0.001). When examining differences for epigenetic age acceleration between PE and normotensive women Hannum, Wu, and PhenoAge DNAmAge estimates (p < 0.001) were significant for both epigenetic age acceleration and intrinsic acceleration models. We found that accelerated maternal DNAmAge is increased in women with PE in some models of epigenetic aging. This research underlines the importance for further investigation into the potential changes of differential DNA methylation in PE.

Maternal hypertensive disorders in pregnancy and early childhood cardiometabolic risk factors: The Generation R Study

The objective of this study was to determine the associations between hypertensive disorders of pregnancy and early childhood cardiometabolic risk factors in the offspring. Therefore, 7794 women from the Generation Rotterdam Study were included, an ongoing population-based prospective birth cohort. Women with a hypertensive disorder of pregnancy were classified as such when they were affected by pregnancy induced hypertension, pre-eclampsia or the haemolysis, elevated liver enzymes and low platelet count (HELLP) syndrome during pregnancy. Early childhood cardiometabolic risk factors were defined as the body mass index at the age of 2, 6, 12, 36 months and 6 years. Additionally, it included systolic blood pressure, diastolic blood pressure, total fat mass, cholesterol, triglycerides, insulin and clustering of cardiometabolic risk factors at 6 years of age. Sex-specific differences in the associations between hypertensive disorders and early childhood cardiometabolic risk factors were investigated. Maternal hypertensive disorders of pregnancy were inversely associated with childhood body mass index at 12 months (confounder model: -0.15 SD, 95% CI -0.27; -0.03) and childhood triglyceride at 6 years of age (confounder model: -0.28 SD, 95% CI -0.45; -0.10). For the association with triglycerides, this was only present in girls. Maternal hypertensive disorders of pregnancy were not associated with childhood body mass index at 2, 6 and 36 months. No associations were observed between maternal hypertensive disorders of pregnancy and systolic blood pressure, diastolic blood pressure, body mass index, fat mass index and cholesterol levels at 6 years of age. Our findings do not support an independent and consistent association between maternal hypertensive disorders of pregnancy and early childhood cardiometabolic risk factors in their offspring. However, this does not rule out possible longer term effects of maternal hypertensive disorders of pregnancy on offspring cardiometabolic health.

Preeclampsia and Cardiovascular Risk for Offspring

There is growing evidence of long-term cardiovascular sequelae in children after in utero exposure to preeclampsia. Maternal hypertension and/or placental ischaemia during pregnancy increase the risk of hypertension, stroke, diabetes, and cardiovascular disease (CVD) in the offspring later in life. The mechanisms associated with CVD seem to be a combination of genetic, molecular, and environmental factors which can be defined as fetal and postnatal programming. The aim of this paper is to discuss the relationship between pregnancy complicated by preeclampsia and possibility of CVD in the offspring. Unfortunately, due to its multifactorial nature, a clear dependency mechanism between preeclampsia and CVD is difficult to establish.

Risk factors for preeclampsia and eclampsia at a main referral maternity hospital in Freetown, Sierra Leone: a case-control study

BACKGROUND

In the African region, 5.6% of pregnancies are estimated to be complicated by preeclampsia and 2.9% by eclampsia, with almost one in ten maternal deaths being associated with hypertensive disorders. In Sierra Leone, representing one of the countries with the highest maternal mortality rates in the world, 16% of maternal deaths were caused by pregnancy-induced hypertension in 2016. In the light of the high burden of preeclampsia and eclampsia (PrE/E) in Sierra Leone, we aimed at assessing population-based risk factors for PrE/E to offer improved management for women at risk.

METHODS

A facility-based, unmatched observational case-control study was conducted in Princess Christian Maternity Hospital (PCMH). PCMH is situated in Freetown and is the only health care facility providing 'Comprehensive Emergency Obstetric and Neonatal Care services' throughout the entire country. Cases were defined as pregnant or postpartum women diagnosed with PrE/E, and controls as normotensive postpartum women. Data collection was performed with a questionnaire assessing a wide spectrum of factors influencing pregnant women's health. Statistical analysis was performed by estimating a binary logistic regression model.

RESULTS

We analyzed data of 672 women, 214 cases and 458 controls. The analysis yielded several independent predictors for PrE/E, including family predisposition for PrE/E (AOR = 2.72, 95% CI: 1.46-5.07), preexisting hypertension (AOR = 3.64, 95% CI: 1.32-10.06), a high mid-upper arm circumflex (AOR = 3.09, 95% CI: 1.83-5.22), presence of urinary tract infection during pregnancy (AOR = 2.02, 95% CI: 1.28-3.19), presence of prolonged diarrhoea during pregnancy (AOR = 2.81, 95% CI: 1.63-4.86), low maternal assets (AOR = 2.56, 95% CI: 1.63-4.02), inadequate fruit intake (AOR = 2.58, 95% CI: 1.64-4.06), well or borehole water as the main source of drinking water (AOR = 2.05, 95% CI: 1.31-3.23) and living close to a waste deposit (AOR = 1.94, 95% CI: 1.15-3.25).

CONCLUSION

Our findings suggest that systematic assessment of identified PrE/E risk factors, including a family predisposition for PrE/E, preexisting hypertension, or obesity, should be performed early on in ANC, followed by continued close monitoring of first signs and symptoms of PrE/E. Additionally, counseling on nutrition, exercise, and water safety is needed throughout pregnancy as well as education on improved hygiene behavior. Further research on sources of environmental pollution in Freetown is urgently required.

Association of family history with incidence and gestational hypertension outcomes of preeclampsia

Background

Gestational hypertension and preeclampsia are hypertensive disorders related to pregnancy that can cause maternal morbidity and fetal growth retardation. The association of these disorders with family history remains unclear.

Objectives

To examine the degree of family aggregation of preeclampsia and gestational hypertension in Taiwan.

Methods

The study was conducted using the data from the National Health Insurance Database of Taiwan. Delivery events in Taiwan from 1999 to 2013 were collected. Preeclampsia was identified based on the hospital diagnosis of index delivery. The family aggregation pattern of preeclampsia was assessed and analyzed using the relationship registered in the database with the patients.

Results

A total of 60,314 preeclampsia events were identified among 4,091,641 deliveries, accounting for 1.5% of the cohort. The incidence of preeclampsia increased with maternal age. A total of 768 preeclampsia events occurred in mothers who had a sororal history of preeclampsia (n = 20,704), accounting for 1.3% of all preeclampsia events (n = 60,314). Mothers who had a sororal history of preeclampsia had a relative risk (RR) of 2.6 (95% confidence interval [CI]: 2.41-2.80) for preeclampsia compared with mothers who did not have a sororal history of preeclampsia. The RR for gestational hypertension was 2.79 (95% CI: 2.36-3.3) in mothers with a positive sororal history of gestational hypertension.

Conclusions

Having a sororal history of preeclampsia was a strong risk factor for preeclampsia and gestational hypertension in mothers in Taiwan. The pattern of family aggregation was similar at all maternal ages.

Novel associations of SNPs MYLIP rs3757354 and ABCA1 2230806 gene with early-onset-preeclampsia: A case-control candidate genetic study

OBJECTIVE

To investigate the association between MYLIP rs3757354 and ABCA1 2230806 single nucleotide polymorphisms in women with preeclampsia in China.

STUDY DESIGN

The case-control study involved 205 patients with preeclampsia and 145 controls. All women with preeclampsia were divided into two groups: 78 patients with early-onset preeclampsia and 127 with late-onset preeclampsia.

MAIN OUTCOME MEASURE

MYLIP rs3757354 and ABCA1 rs2230806 SNPs were analyzed through multiplex PCR for targeted next-generation sequencing technology. A secondary outcome was lipid profile changes and liver function in women with PE.

RESULTS

Maternal age (OR: 1.073, 95% CI = 1.006-1.145), BMI (OR: 1.118, 95% CI = 1.040-1.201), TG/HDL-C (OR: 1.536, 95% CI = 1.080-2.183), and TT genotype of SNP rs3757354 (OR: 3.238, 95% CI = 1.313-7.990) were associated with EOPE risk. Our study found that patients with TT genotype of ABCA1 rs2230806 had more severe hepatic dysfunction and higher HDL levels in the EOPE group compared with CC/CT genotype. There was no association between rs2230806 and the risk of PE.

CONCLUSION

The polymorphisms of rs3757354 are associated with the risk of EOPE in Chinese pregnant women. The TT genotype in ABCA1 rs2230806 is a strong predictive risk for elevated aminotransferase levels in pregnant women with EOPE.

Risk of pre-eclampsia in patients with a maternal genetic predisposition to common medical conditions: a case-control study

OBJECTIVE

To assess whether women with a genetic predisposition to medical conditions known to increase pre-eclampsia risk have an increased risk of pre-eclampsia in pregnancy.

DESIGN

Case-control study.

SETTING AND POPULATION

Pre-eclampsia cases (n = 498) and controls (n = 1864) in women of European ancestry from five US sites genotyped on a cardiovascular gene-centric array.

METHODS

Significant single-nucleotide polymorphisms (SNPs) from 21 traits in seven disease categories (cardiovascular, inflammatory/autoimmune, insulin resistance, liver, obesity, renal and thrombophilia) with published genome-wide association studies (GWAS) were used to create a genetic instrument for each trait. Multivariable logistic regression was used to test the association of each continuous scaled genetic instrument with pre-eclampsia. Odds of pre-eclampsia were compared across quartiles of the genetic instrument and evaluated for significance.

MAIN OUTCOME MEASURES

Genetic predisposition to medical conditions and relationship with pre-eclampsia.

RESULTS

An increasing burden of risk alleles for elevated diastolic blood pressure (DBP) and increased body mass index (BMI) were associated with an increased risk of pre-eclampsia (DBP, overall OR 1.11, 95% CI 1.01-1.21, P = 0.025; BMI, OR 1.10, 95% CI 1.00-1.20, P = 0.042), whereas alleles associated with elevated alkaline phosphatase (ALP) were protective (OR 0.89, 95% CI 0.82-0.97, P = 0.008), driven primarily by pleiotropic effects of variants in the FADS gene region. The effect of DBP genetic loci was even greater in early-onset pre-eclampsia cases (at <34 weeks of gestation, OR 1.30, 95% CI 1.08-1.56, P = 0.005). For other traits, there was no evidence of an association.

CONCLUSIONS

These results suggest that the underlying genetic architecture of pre-eclampsia may be shared with other disorders, specifically hypertension and obesity.

TWEETABLE ABSTRACT

A genetic predisposition to increased diastolic blood pressure and obesity increases the risk of pre-eclampsia.

Family history of chronic illness, preterm gestational age and smoking exposure before pregnancy increases the probability of preeclampsia in Omo district in southern Ethiopia: a case-control study

BACKGROUND

Preeclampsia is a complex syndrome that is considered a disorder specific to pregnancy. However, research indicates that diffuse maternal endothelial damage may persist after childbirth. On the other hand, women who had a history of pre-eclampsia are at an increased risk of vascular disease. Considering that the multifactorial nature of pre-eclampsia in a remote health setting, knowledge of risk factors of preeclampsia gives epidemiological significance specific to the study area. Therefore, this study aimed to identify the determinants of preeclampsia among pregnant women attending perinatal service in Omo district Hospitals in southern Ethiopia.

METHODS

An institution-based unmatched case-control study design was conducted among women visiting for perinatal service in Omo District public hospitals between February to August 2018. A total of 167 cases and 352 controls were included. Data were collected via face-to-face interviews. Bivariable and multivariable logistic regression analysis were computed to examine the effect of the independent variable on preeclampsia using Statistical Package for Social Sciences version 26 window compatible software. Variables with a p-value of less than 0.05 were considered statistically significant.

RESULTS

Factors that were found to have a statistically significant association with pre-eclampsia were primary relatives who had history of chronic hypertension (AOR 2.1, 95% CI: 1.06-4.21), family history of diabetes mellitus (AOR 2.35; 95% CI: 1.07-5.20), preterm gestation(AOR = 1.56, 95%CI, 1.05-2.32), and pre-conception smoking exposure (AOR = 4.16, 95%CI, 1.1-15.4).

CONCLUSIONS

The study identified the risk factors for pre-eclampsia. Early detection and timely intervention to manage pre-eclampsia, and obstetric care providers need to emphasize women at preterm gestation and a history of smoking before pregnancy.

Association of Maternal Regulatory Single Nucleotide Polymorphic CD99 Genotype with Preeclampsia in Pregnancies Carrying Male Fetuses in Ethiopian Women

Preeclampsia (PE) is a human specific syndrome with unknown etiology causing maternal and fetal morbidities and mortalities. In PE, maternal inflammatory responses are more exaggerated if the fetus is male than female. Other pregnancy complications such as spontaneous abortions are also more common if the fetus is male. Recent transcriptome findings showed an increased expression of CD99 in erythroid cells from male cord blood in PE. The single nucleotide polymorphism (SNP) rs311103, located in a GATA-binding site in a regulatory region on the X/Y chromosomes, governs a coordinated expression of the Xg blood group members CD99 and Xg^a in hematopoietic cells in a sex-dependent fashion. The rs311103C disrupts the GATA-binding site, resulting in decreased CD99 expression. We aimed to investigate the association between PE and the allele frequency of rs311103 in pregnancies in a fetal sex-dependent fashion. In a case-controlled study, we included 241 pregnant women, i.e., 105 PE cases and 136 normotensive controls. A SNP allelic discrimination analysis was performed on DNA from maternal venous blood and fetal cord blood by qPCR. A statistically significant association was observed between rs311103 allele frequency and PE in mothers carrying male fetuses. Therefore, the rs311103 genotype may play a role in the pathogenesis of PE in a fetal sex-specific manner.

Polymorphism in killer cell immunoglobulin-like receptors and human leukocyte antigen-c and predisposition to preeclampsia in Ethiopian pregnant women population

INTRODUCTION

Preeclampsia (PE) is a human specific pregnancy-related syndrome of unknown etiology that affects 2-8 % of pregnancies. Polymorphism in maternal Killer Cell Immunoglobulin-like Receptors (KIRs) and the ligand fetal Human Leukocyte Antigen-C (HLA-C) may predispose pregnant mothers for PE due to defective trophoblast invasion into the maternal decidua. Our study aimed to investigate the association between maternal KIR and fetal HLA-C polymorphism and PE in Ethiopian pregnant women.

METHODS

We included a total of 288 (157 controls and 131 PE cases) in a case-controls study at Adama Regional Referral Hospital, Ethiopia. The KIR and HLA-C genotyping was done using traditional polymerase chain reaction on genomic DNA extracted form maternal venous and cord blood followed by 2% agarose gel electrophoresis.

RESULTS

The statistical associations between variables were evaluated using Pearson's Chi-square test. P < 0.05, with 95 % confidence interval was considered statistically significant. A significant association was observed between the KIR2DS1 and PE, with a higher frequency (60.5 %) of the gene in the control group. Similarly, a significant association was observed between KIR AA genotype and PE, with a higher frequency (38.2 %) of this genotype in the PE group. Ethiopians share the same risk genotype for PE as seen in previous African and European studies, namely homozygosity of a maternal KIR AA genotype. However, Ethiopians differ from other East African populations by sharing the same protective KIR2DS1 gene as Europeans.

A maternal GOT1 novel variant associated with early-onset severe preeclampsia identified by whole-exome sequencing

BACKGROUND

This study wants to know the genetic cause of preeclampsia (PE) which is a leading cause of maternal and perinatal death, but the underlying molecular mechanisms that cause PE remain poorly understood. Many single nucleotide polymorphisms have been identified by genome-wide association studies and were found to be associated with PE; however, few studies have used whole-exome sequencing (WES) to identify PE variants.

METHODS

Five patients with severe early-onset preeclampsia (EOPE) were recruited, and WES was performed on each patient. Sanger sequencing was used to confirm the potential causative genetic variant.

RESULTS

After a stringent bioinformatics analysis, a rare variant in the GOT1 gene, c.44C > G:p.P15R, was found in one patient. Bioinformatics analysis showed that the variant site is highly conserved across several species and was predicted to be a pathogenic variant according to several online mutational function prediction software packages. Further structural biology homology modeling suggested that P15R would change the electric environment of enzymatic center, and might affect the binding affinity of substrate or product.

CONCLUSION

We demonstrated for the first time that the variant in GOT1 may be associated with EOPE, the results of this study provide researchers and clinicians with a better understanding of the molecular mechanisms that underlie maternal severe EOPE.

Immunological Role of the Maternal Uterine Microbiome in Pregnancy: Pregnancies Pathologies and Alterated Microbiota

Understanding what happens at the time of embryo implantation has been the subject of significant research. Investigators from many differing fields including maternal fetal medicine, microbiology, genetics, reproductive endocrinology and immunology have all been studying the moment the embryo interacts with the maternal endometrium. A perfect relationship between the uterus and the embryo, mediated by a tightly controlled interaction between the embryo and the endometrium, is required for successful implantation. Any factors affecting this communication, such as altered microbiome may lead to poor reproductive outcomes. Current theories suggest that altered microbiota may trigger an inflammatory response in the endometrium that affects the success of embryo implantation, as inflammatory mediators are tightly regulated during the adhesion of the blastocyst to the epithelial endometrial wall. In this review, we will highlight the various microbiome found during the periconceptual period, the microbiomes interaction with immunological responses surrounding the time of implantation, its effect on implantation, placentation and ultimately maternal and neonatal outcomes.

Family history of pre-eclampsia and cardiovascular disease as risk factors for pre-eclampsia: the GenPE case-control study

Objective: To determine whether family history of pre-eclampsia and cardiovascular disease is consistently associated with the occurrence of pre-eclampsia sub-phenotypes and fetal growth restriction (FGR).Material and Methods: We conducted a case-control study in which cases of pre-eclampsia and healthy pregnant controls were recruited at the time of delivery from eight Colombian cities between 2000 and 2012. Odds of pre-eclampsia among women with a positive family history of pre-eclampsia or cardiovascular disease were compared to women without affected relatives (logistic regression modeling and multinomial logistic regression model [Ajusted]).Results: A total of 3510 pre-eclampsia cases and 4512 controls with data on family history of pre-eclampsia were included in analyses. A subsample of 3086 cases and 3888 controls also provided information on family history of cardiovascular disease. Women whose mothers had pre-eclampsia had 3.38 (95% CI 2.89, 3.96) higher odds than those who did not, and having an affected sister increased pre-eclampsia odds by 2.43 (95% CI 2.02, 2.93). The effect of having both mother and sister affected with pre-eclampsia was stronger than the two independent risk factors (OR 4.17 [95% CI 2.60, 6.69]). Women with parental history of cardiovascular disease also had an increased risk of pre-eclampsia (OR 1.58 [95% CI 1.24, 2.01]).Conclusions: Family history of pre-eclampsia increased the risk of PE. The impact of family history of cardiovascular disease on pre-eclampsia was more conservative, but serves to support the hypothesis that pre-eclampsia may reflect the premature exposure of underlying cardiovascular dysfunction, precipitated by the stress test of pregnancy.

Polymorphisms within vitamin D binding protein gene within a Preeclamptic South African population

Objectives: The vitamin D binding protein encoded by the GC gene contains two single nucleotide polymorphisms (rs4588 and rs7041) that have been associated with disease outcome, these include periodontitis coronary heart disease and hypertension. In pregnancy, these SNPs influence vitamin D metabolism that could result in hypertensive disorders such as PE. The etiology of PE, still remains elusive. The aim of this study was to evaluate the distribution of rs4588 and rs7041 within the GC gene among PE and normotensive pregnant women, residing in Durban, KwaZulu-Natal, South Africa. Study design: Our study consisted of n = 600 participants (normotensive (n = 246, N); early onset PE (n = 167, EOPE); and late-onset PE (n = 246, LOPE)). We extracted DNA from whole blood and genotyped for rs4588 and rs7041 SNPs using the TaqMan assay. Results: Regardless of HIV status, we observed the rs4588 (CC genotype) more frequently in PE (EOPE+LOPE) compared to the normotensive participants with an OD ratio of 0.74 (95% CI, 0.35-1.5; p < 0.001). We report a significant difference in the frequency of rs7041 (GT genotype) in the EOPE group compared to the normotensive group with an OD ratio of 11.48 (95% CI, 2.6-103.7; p < 0.001). The rs7041 GT genotype had a higher frequency in the EOPE compared to the LOPE group, with an OD ratio of 15.15 (95% CI, 2.3-639.2; p < 0.001). Conclusion: This is the first study to describe the prevalence of SNPs of the rs4588 and rs7041 within the GC gene in women with PE within the high HIV endemic area of KZN, South Africa. Notably, a significant association of the rs7041 (TT genotype) and rs4588 (CC genotype) occurred at a higher frequency in PE compared to the normotensive cohort. Future studies will examine the functional effect of the GC region in relation to pregnancy and vitamin D deficiency.

Could circRNA be a new biomarker for pre-eclampsia?

Pre-eclampsia is a devastating complication of pregnancy which is characterized by hypertension and proteinuria in pregnant women. Pre-eclampsia is important as it is the leading cause of death. Moreover, untreated pre-eclampsia might lead to other lethal complications, for both fetus and mother. Pre-eclampsia can also affect the quality of life in affected women. Despite a large number of risk factors for pre-eclampsia, these risk factors are able to detect just 30% of women who are susceptible to pre-eclampsia. Heterogeneous manifestations of pre-eclampsia necessitate the discovery of potential biomarkers required for its early detection. Circular RNAs (circRNAs) are a type of RNA which are more abundant, specific, and highly organized compared with other types of RNA. Accordingly, circRNAs have been suggested as one of the potential biomarkers for different diseases. Recently, researchers have shown interest in the effects of circRNAs in pre-eclampsia, although the current evidence is limited. The majority of obstetricians are probably not aware of circRNAs as a useful biomarker. Here, we aimed to summarize recent supporting evidence and assess the mechanisms by which circRNAs are involved in pre-eclampsia.

Distribution of Polymorphisms of the Renin-Angiotensin System Genes (ACE, AGT, and AGTR1), ITGB3, and FTO in Pregnant Patients with Hypertensive Disorders

The study included pregnant women aged 23-41 years with preeclampsia and gestation-associated arterial hypertension at weeks 27-40 and patients with essential arterial hypertension developing under conditions of the metabolic syndrome and without it. Frequency analysis of polymorphisms of the renin-angiotensin system genes (ACE, AGT, and AGTR1), ITGB3, FTO and their associations confirmed the syndrome nature of hypertensive disorders in pregnancy. The presence allele T of AGT gene and/or allele C of AGTR1 gene in the genotype of patients with preeclampsia was associated with higher BP and pressure load over 24 h. Allele D of ACE gene was also essential for BP parameters (pressure load) in patients with preeclampsia and gestation-associated arterial hypertension. Due to high genetic heterogeneity of the preeclampsia syndrome and genetic differences in the incidence of the studied gene polymorphisms in preeclampsia and gestation-associated arterial hypertension, no direct associations between these gestation disorders and polymorphic markers of the renin-angiotensin system genes can be established. However, polymorphisms of the renin-angiotensin system genes are essential for the 24-h dynamics of BP and pressure load under conditions of hypertensive disorders in pregnancy.

Association study of M235T and A-6G polymorphisms in angiotensinogen gene with risk of developing preeclampsia in Iranian population

OBJECTIVE

Preeclampsia (PE) is a life-threatening complication of pregnancy that accounts for 12% of all maternal deaths worldwide. The aim of this study is to investigate the relationships between the polymorphisms of angiotensinogen (AGT) gene and preeclampsia.

MATERIAL AND METHODS

In this study, 240 unrelated preeclampsia patients and 178 normotensive women were examined. Genomic DNA was extracted then we assessed M235T(C/T) and A-6G polymorphisms of the AGT gene. Genotyping of M235T and A-6G polymorphisms were performed using SSP-PCR and MS-PCR, respectively.

RESULTS

A significant protective association was observed between A-6G G allele, A-6G A/G heterozygote genotype (OR = 0.6, p = 0.007 and OR = 0.6, p = 0.04) against PE. Furthermore, it was shown that two copies of A-6G A allele would increase PE risk (OR: 0.62, p = 0.04). Our results did not show a significant association for M235T polymorphism and PE. However, the combinations of A-6G A/A genotype and M235T T/C genotype (OR = 0.4, p = 0.02) and also A-6G A/G genotype and M235T T/C genotype (OR = 0.5, p = 0.04) in controls represented a significant protective association against PE.

CONCLUSION

According to the existence of significant correlation between two candidate polymorphisms, A-6G and M235T polymorphisms, with PE disease in our study, they may be considered as valuable factors in susceptibility to PE disease in Iranian women.

Analysis of the Epigenome in Multiplex Pre-eclampsia Families Identifies SORD, DGKI, and ICA1 as Novel Candidate Risk Genes

Pre-eclampsia is a serious heritable disorder that affects 5-8% of pregnancies worldwide. While classical genetic studies have identified several susceptibility genes they do not fully explain the heritability of pre-eclampsia. An additional contribution to risk can be quantified by examining the epigenome, in particular the methylome, which is a representation of interactions between environmental and genetic influences on the phenotype. Current array-based epigenetic studies only examine 2-5% of the methylome. Here, we used whole-genome bisulfite sequencing (WGBS) to determine the entire methylome of 13 individuals from two multiplex pre-eclampsia families, comprising one woman with eclampsia, six women with pre-eclampsia, four women with uncomplicated normotensive pregnancies and two male relatives. The analysis of WGBS profiles using two bioinformatics platforms, BSmooth and Bismark, revealed 18,909 differentially methylated CpGs and 4157 differentially methylated regions (DMRs) concordant in females. The methylation patterns support the involvement of previously reported candidate genes, including COL4A1, SLC2A4, PER3, FLT1, GPI, LCT, DDAH1, TGFB3, DLX5, and LRP1B. Statistical analysis of DMRs revealed three novel genes significantly correlated with pre-eclampsia: sorbitol dehydrogenase (SORD, p = 9.98 × 10^-6), diacylglycerol kinase iota (DGKI, p = 2.52 × 10^-5), and islet cell autoantigen 1 (ICA1, 7.54 × 10^-3), demonstrating the potential of WGBS in families for elucidating the role of epigenome in pre-eclampsia and other complex diseases.

Vitamin D metabolic loci and preeclampsia risk in multi-ethnic pregnant women

Allelic variants in vitamin D metabolism genes may increase the risk of preeclampsia, but few studies have systematically tested this hypothesis. Our objective was to evaluate the relationship between maternal allelic variants in three vitamin D metabolism genes and risk of preeclampsia. Samples were from two case‐control studies of pregnant women who delivered in Pittsburgh, PA from 1999 to 2010 and twelve recruiting sites across the United States from 1959 to 1965. Single‐nucleotide polymorphisms (SNPs) were genotyped 50 kilobases up‐ and down‐stream in three genes (VDR,GC, and CYP27B1) in the samples from both studies, for a total of 744 preeclampsia cases and 2411 controls. Using multivariable logistic regression, we estimated the associations between allelic variation in each locus and preeclampsia risk by maternal race and study. Meta‐analysis was used to estimate the association across race‐study groups for each SNP. Minor allele of a noncoding region of the VDR gene was significantly associated with preeclampsia risk, which was verified in the meta‐analysis [odds ratio (OR), 95% confidence intervals (CI)] after adjusting for multiple comparisons [rs12831006:1.5 (1.2, 2.0), P < 0.0001]. The meta‐analysis identified associations for one intron GC variant [rs843010:1.4 (1.1, 1.9) P < 0.05] and two variants of the flanking region of GC [rs842991:1.5 (1.1, 2.0) P < 0.05; rs16846876:0.75 (0.58, 0.98) P < 0.05]. There were no statistically significant associations for CYP27B1 SNPs. Our results provide additional support for a biological role of vitamin D in preeclampsia.

Serum endocan concentration and its correlation with severity of hypertensive disorders in pregnancy

Introduction: Endocan plays a role in the development of vascular tissue in health and disease and is an indicator of endothelial cells activation and angiogenesis.Objective: The aim of this study was to investigate the relationship between endocan serum levels and various types of hypertensive disorders in pregnant women.Patients and methods: We created three study groups (preeclampsia [n = 60], chronic hypertension [n = 39], gestational hypertension [n = 58]) and the control group consisting of 59 healthy pregnant women. The endocan serum concentration was assessed using commercially available ELISA kit.Results: There were no statistically significant differences in endocan serum levels (pg/mL) in each study group compared to controls. The multiple regression did not reveal significant differences between endocan levels in each study group after adjustment for prepregnancy BMI. We did not find any significant correlations between the endocan serum level and patients' age, gestational age (GA) at sample collection, prepregnancy BMI, systolic blood pressure, diastolic blood pressure, and 24-hour urinary protein excretion in each analyzed group. Moreover, in the preeclamptic participants, we did not observe a significant relationship between the endocan concentration and the features indicating the severity of the disease other than elevated blood pressure. There were no differences in endocan serum level in preeclampsia subgroups: early-onset versus late-onset and mild versus severe preeclampsia.Conclusions: Endocan is not involved in the pathogenesis of hypertensive disorders in pregnant women and could not be regarded as a marker of endothelial dysfunction in these cases.

Preeclampsia: Disease biology and burden, its management strategies with reference to India

Preeclampsia is the cause of significant maternal and fetal mortality and morbidity. It is characterized by new-onset hypertension and proteinuria after 20 weeks of gestation. Preeclamptic women and children born from preeclamptic pregnancies are at greater risk to develop severe cardiovascular complications and metabolic syndromes later in life. The incidence of preeclampsia is estimated to be seven times higher in developing countries as compared to the developed countries. This review summarizes the pathophysiology of preeclampsia, emerging new hypothesis of its origin, risk factors that make women susceptible to developing preeclampsia and the potential of various biomarkers being studied to predict preeclampsia. The health care of developing countries is continuously challenged by substantial burden of maternal and fetal mortality. India despite being a fast developing country, is still far behind in achieving the required maternal mortality rates as per Millennium Development Goals set by the World Health Organization. Further, this review discusses the prevalence of preeclampsia in India, health facilities to manage preeclampsia, current guidelines and protocols followed and government policies to combat this complication in Indian condition.

Gene-Centric Analysis of Preeclampsia Identifies Maternal Association at PLEKHG1

The genetic susceptibility to preeclampsia, a pregnancy-specific complication with significant maternal and fetal morbidity, has been poorly characterized. To identify maternal genes associated with preeclampsia risk, we assembled 498 cases and 1864 controls of European ancestry from preeclampsia case-control collections in 5 different US sites (with additional matched population controls), genotyped samples on a cardiovascular gene-centric array composed of variants from ≈2000 genes selected based on prior genetic studies of cardiovascular and metabolic diseases and performed case-control genetic association analysis on 27 429 variants passing quality control. In silico replication testing of 9 lead signals with P<10-4 was performed in independent European samples from the SOPHIA (Study of Pregnancy Hypertension in Iowa) and Inova cohorts (212 cases, 456 controls). Multiethnic assessment of lead signals was then performed in samples of black (26 cases, 136 controls), Hispanic (132 cases, 468 controls), and East Asian (9 cases, 80 controls) ancestry. Multiethnic meta-analysis (877 cases, 3004 controls) revealed a study-wide statistically significant association of the rs9478812 variant in the pleiotropic PLEKHG1 gene (odds ratio, 1.40 [1.23-1.60]; Pmeta=5.90×10-7). The rs9478812 effect was even stronger in the subset of European cases with known early-onset preeclampsia (236 cases diagnosed <37 weeks, 1864 controls; odds ratio, 1.59 [1.27-1.98]; P=4.01×10-5). PLEKHG1 variants have previously been implicated in genome-wide association studies of blood pressure, body weight, and neurological disorders. Although larger studies are required to further define maternal preeclampsia heritability, this study identifies a novel maternal risk locus for further investigation.

NLRP genes and their role in preeclampsia and multi-locus imprinting disorders

Preeclampsia (PE) affects 2-5% of all pregnancies. It is a multifactorial disease, but it has been estimated that 35% of the variance in liability of PE are attributable to maternal genetic effects and 20% to fetal genetic effects. PE has also been reported in women delivering children with Beckwith-Wiedemann syndrome (BWS, OMIM 130650), a disorder associated with aberrant methylation at genomically imprinted loci. Among others, members of the NLRP gene family are involved in the etiology of imprinting defects. Thus, a functional link between PE, NLRP gene mutations and aberrant imprinting can be assumed. Therefore we analyzed a cohort of 47 PE patients for NLRP gene mutations by next generation sequencing. In 25 fetuses where DNA was available we determined the methylation status at the imprinted locus. With the exception of one woman heterozygous for a missense variant in the NLRP7 gene (NM_001127255.1(NLRP7):c.542G>C) we could not identify further carriers, in the fetal DNA normal methylation patterns were observed. Thus, our negative screening results in a well-defined cohort indicate that NLRP mutations are not a relevant cause of PE, though strong evidence for a functional link between NLRP mutations, PE and aberrant methylation exist.

Maternal pre-eclampsia and long-term offspring health: Is there a shadow cast?

Pre-eclampsia is a common pregnancy disorder with important short-term complications for mother and baby. Evidence suggests pre-eclampsia also has implications for the mother beyond pregnancy, as well as long-term effects on offspring health. Limited research has linked pre-eclampsia with changes in offspring blood pressure, BMI, and stroke risk. Underpinning mechanisms are poorly understood, but developmental programming may be involved. Research in this area has been hindered by difficulties in defining pre-eclampsia and problems with study design. Further targeted evaluation through to adulthood is required to determine the long-term impact of pre-eclampsia on offspring disease risk and how this develops.

Genetic predisposition to preeclampsia is conferred by fetal DNA variants near FLT1, a gene involved in the regulation of angiogenesis

Preeclampsia risk is influenced by both the mother's genetic background and the genetics of her fetus; however, the specific genes responsible for conferring preeclampsia risk have largely remained elusive. Evidence that preeclampsia has a genetic predisposition was first detailed in the early 1960s, and overall preeclampsia heritability is estimated at ∼55%. Many traditional gene discovery approaches have been used to investigate the specific genes that contribute to preeclampsia risk, but these have largely not been successful or reproducible. Over the past decade, genome-wide association studies have allowed for significant advances in the understanding of the genetic basis of many common diseases. Genome-wide association studies are predicated on the idea that the genetic basis of many common diseases are complex and polygenic with many variants, each with modest effects that contribute to disease risk. Using this approach in preeclampsia, a large genome-wide association study recently identified and replicated the first robust fetal genomic region associated with excess risk. A screen of >7 million genetic variants in 2658 offspring from preeclamptic women and 308,292 population controls identified a single association signal close to the Fms-like tyrosine kinase 1 gene, on chromosome 13. Fms-like tyrosine kinase 1 encodes soluble Fms-like tyrosine kinase 1, a splice variant of the vascular endothelial growth factor receptor that exerts antiangiogenic activity by inhibiting signaling of proangiogenic factors. The Fms-like tyrosine kinase 1 pathway is central in preeclampsia pathogenesis because excess circulating soluble Fms-like tyrosine kinase 1 in the maternal plasma leads to the hallmark clinical features of preeclampsia, including hypertension and proteinuria. The success of this landmark fetal preeclampsia genome-wide association study suggests that well-powered, larger maternal and fetal genome-wide association study will be fruitful in identifying additional common variants that implicate causal preeclampsia genes and pathways. Such efforts will rely on the continued development of large preeclampsia consortia focused on preeclampsia genetics to obtain adequate sample sizes, detailed clinical phenotyping, and matched maternal-fetal samples. In summary, the fetal preeclampsia genome-wide association study represents an exciting advance in preeclampsia biology, suggesting that dysregulation at the Fms-like tyrosine kinase 1 locus in the fetal genome (likely in the placenta) is a fundamental molecular defect in preeclampsia.

Maternal eating disorders and perinatal outcomes: A three-generation study in the Norwegian Mother and Child Cohort Study

Previous studies of the relationship between maternal eating disorders and adverse perinatal outcomes have failed to control for familial transmission of perinatal phenotypes, which may confound the reported association. In a unique design afforded by the Norwegian Mother and Child Cohort Study and Medical Birth Registry of Norway, we linked three generations through birth register records and maternal-reported survey data to investigate whether maternal eating disorders increase risk after parsing out the contribution of familial transmission of perinatal phenotypes. The samples were 70,881 pregnancies in grandmother-mother-child triads for analyses concerning eating disorder exposure during pregnancy and 52,348 for analyses concerning lifetime maternal eating disorder exposure. As hypothesized, eating disorders predicted a higher incidence of perinatal complications even after adjusting for grandmaternal perinatal phenotypes. For example, anorexia nervosa immediately prior to pregnancy was associated with smaller birth length (relative risk = 1.62; 95% CI [1.20, 2.14]), bulimia nervosa with induced labor (relative risk = 1.21; 95% CI [1.07, 1.36]), and binge-eating disorder with several delivery complications, larger birth length (relative risk = 1.25; 95% CI [1.17, 1.34]), and large-for-gestational-age (relative risk = 1.04; 95% CI [1.01, 1.06]). Maternal pregravid body mass index and gestational weight mediated most associations. Our results support that exposure to eating disorders increases the risk for negative health outcomes in pregnant women and their babies. (PsycINFO Database Record

Inherited factors contribute to an inverse association between preeclampsia and breast cancer

Background

Preeclampsia is frequently linked to reduced breast cancer risk. However, little is known regarding the underlying genetic association and the association between preeclampsia and mammographic density.

Methods

This study estimates the incidence rate ratios (IRRs) of breast cancer in patients with preeclampsia, when compared to women without preeclampsia, using Poisson regression models in two cohorts of pregnant women: a Swedish nationwide cohort (n = 1,337,934, 1973–2011) and the Karolinska Mammography Project for Risk Prediction of Breast Cancer (KARMA, n = 55,044, 1958–2015). To identify the genetic association between preeclampsia and breast cancer, we used logistic regression models to calculate the odds ratios (ORs) of preeclampsia in sisters of breast cancer patients, and in women with different percentiles of breast cancer polygenic risk scores (PRS). Linear regression models were used to estimate the mammographic density by preeclampsia status in the KARMA cohort.

Results

A decreased risk of breast cancer was observed among patients with preeclampsia in both the nationwide (IRR = 0.90, 95% CI = 0.85; 0.96) and KARMA cohorts (IRR = 0.75, 95% CI = 0.61; 0.93). Women with high breast cancer PRS and sisters of breast cancer patients had a lower risk of preeclampsia (OR = 0.89, 95% CI = 0.83; 0.96). Mammographic density was lower in women with preeclampsia compared to women without preeclampsia (-2.04%, 95% CI = -2.65; -1.43). Additionally, among sisters in the KARMA cohort (N = 3500), density was lower in sisters of patients with preeclampsia compared to sisters of women without preeclampsia (-2.76%, 95% CI = -4.96; -0.56).

Conclusion

Preeclampsia is associated with reduced risk of breast cancer and mammographic density. Inherited factors contribute to this inverse association.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-017-0930-6) contains supplementary material, which is available to authorized users.

Genetic Approaches in Preeclampsia

Preeclampsia (PE) is a serious hypertensive disorder that affects up to 8% of all pregnancies annually. An established risk factor for PE is family history, clearly demonstrating an underlying genetic component to the disorder. To date, numerous genetic studies, using both the candidate gene and genome-wide approach, have been undertaken to tease out the genetic basis of PE and understand its origins. Such studies have identified some promising candidate genes such as STOX1 and ACVR2A. Nevertheless, researchers face ongoing challenges of replicating these genetic associations in different populations and performing the functional validation of identified genetic variants to determine their causality in the disorder. This chapter will review the genetic approaches used in the study of PE, discuss their limitations and possible confounders, and describe current strategies.

Association between ABO and Rh Blood Groups and Risk of Preeclampsia: A Case-Control Study from Iran

AIM:

Preeclampsia (PE) is a major cause of maternal and neonatal morbidity and mortality. There is a genetic component in the development of PE with estimated heritability around 0.47. Several studies have investigated the association between maternal ABO blood groups (OMIM 110300) and risk of PE, with contradictory results have emerged. Considering that there is no study in this filed from Iranian population, the present case-control study was carried out at Shiraz (south-west Iran).

MATERIAL AND METHODS:

In this study 331 women; 121 pregnant with PE and 210 normotensive pregnant women were included. Using blood group O (for ABO blood groups) or Rh+ (for Rh blood groups) as a reference, odds ratios (ORs) and its 95% confidence intervals (95% CI) of PE risk were estimated from logistic regression analysis.

RESULTS:

Although the A (OR = 0.67, 95% CI = 0.39-1.17, P = 0.165), B (OR = 0.86, 95% CI = 0.48-1.53, P = 0.615) and AB (OR = 1.14, 95% CI = 0.37-3.45, P = 0.812) phenotypes showed lower risks compared with the O blood group, statistical analysis indicated that there was no significant association between ABO phenotypes and risk of PE. The frequency of Rh- phenotype was higher among PE patients compared with the control group. However, the association was not significant (OR = 1.79, 95% CI = 0.69-4.65, P = 0.229). Adjusted ORs for age of participants and parity did not change the above-mentioned associations.

CONCLUSION:

Our present findings indicate that there is no association between ABO and Rh blood groups and risk of PE in Iranian population.

Association of serum concentrations of persistent organic pollutants (POPs) and risk of pre-eclampsia: a case-control study

BACKGROUND

There is increasing evidence that persistent organic pollutants (POPs) may contribute to pre-eclampsia. The objective of this study was to evaluate the association between Polychlorinated Biphenyls (PCBs) and Polybrominated Diphenyl Ethers (PBDEs) as POPs with pre-eclampsia.

METHODS

This case-control study was performed in the three general university hospitals of Tehran University of Medical Sciences. Serum samples were collected from cases (n = 45) who had diagnosed with preeclampsia and from control samples (n = 70) with normal pregnancy and attended the same hospital for a routine prenatal visit at the third trimester of pregnancy. Pollutants levels were analyzed by Gas Chromatography Mass Spectrometry (GC/MS).

RESULTS

Mean participant age was 27.3 ± 5.39 with median 27. As the main independent variable, total POPs manifested with adjusted OR equal to 1.54 (95 % CI: 1.26-1.87, p-value <0.0001), which was significantly associated with pre-eclampsia. The adjusted OR proved a statistically significant association between total PCBs 1.77 (95 % CI: 1.34-2.32) and total PBDEs (OR = 2.19; 95 % CI: 1.39-3.45, p-value = 0.001) with pre-eclampsia considering confounding variables (maternal age, pre-pregnancy body mass index (BMI), gestational age, weight gain during pregnancy and total lipids in maternal serum). Finally, pre-pregnancy BMI and weight gain during pregnancy had a positive association with pre-eclampsia and gestational age yielded a negative association with pre-eclampsia in all analysis.

CONCLUSION

Our data indicate the association between total POPs, total PBDEs, and total PCBs with pre-eclampsia, even after controlling for the effects of a number of potentially confounding factors. Further investigation about route of exposure and the trend of POPs especially in pregnant women is needed.