The Role of Uric Acid in Preeclampsia: Is Uric Acid a Causative Factor or a Sign of Preeclampsia?

Risk factors for preeclampsia in patients with chronic kidney disease primarily focused on stage 1 CKD. Are referred and registered patients alike?

Limited research exists on identifying risk factors for preeclampsia (PE) in the chronic kidney disease (CKD) population, especially across different patient sources. This study aimed to address this gap by analyzing clinical data from CKD pregnant women admitted to Peking University Third Hospital from January 2012 to December 2022. Logistic regression analysis identified independent risk factors for PE in the CKD population and assessed variations among patients from different sources. Additionally, a predictive model for PE was established using data from the registered group. The study included 524 CKD patients. Hypertension, proteinuria, fibrinogen >4 g/L, serum albumin ≤30 g/L, and uric acid >260 μmol/L were independent risk factors for PE in the overall CKD population. Subgroup analysis revealed that hypertension, serum albumin ≤30 g/L, and uric acid >260 μmol/L were independent risk factors in the referred group, while hypertension, uric acid >260 μmol/L, and fibrinogen >4 g/L were independent risk factors in the registered group. The prediction model based on registered group risk factors showed good predictive efficiency, with the area under the curve of 0.774 in the training set and 0.714 in the validation set. In conclusion, this study revealed that hypertension and elevated uric acid are independent risk factors for PE in CKD patients regardless of patient source, while serum albumin and fibrinogen levels are associated with PE risk in specific patient subgroups. Our predictive model enables clinicians to quickly identify the risk of PE in CKD patients, and early intervention treatment to improve pregnancy outcomes.

Exploring the Multifaceted Nexus of Uric Acid and Health: A Review of Recent Studies on Diverse Diseases

The prevalence of patients with hyperuricemia or gout is increasing worldwide. Hyperuricemia and gout are primarily attributed to genetic factors, along with lifestyle factors like consuming a purine-rich diet, alcohol and/or fructose intake, and physical activity. While numerous studies have reported various comorbidities linked to hyperuricemia or gout, the range of these associations is extensive. This review article focuses on the relationship between uric acid and thirteen specific domains: transporters, genetic factors, diet, lifestyle, gout, diabetes mellitus, metabolic syndrome, atherosclerosis, hypertension, kidney diseases, cardiovascular diseases, neurological diseases, and malignancies. The present article provides a comprehensive review of recent developments in these areas, compiled by experts from the Young Committee of the Japanese Society of Gout and Uric and Nucleic Acids. The consolidated summary serves to enhance the global comprehension of uric acid-related matters.

Impact of Angiogenic and Cardiovascular Biomarkers for Prediction of Placental Dysfunction in the First Trimester of Pregnancy

Algorithms for first-trimester prediction of pre-eclampsia usually include maternal risk factors, blood pressure, placental growth factor (PlGF), and uterine artery Doppler pulsatility index. However, these models lack sensitivity for the prediction of late-onset pre-eclampsia and other placental complications of pregnancy, such as small for gestational age infants or preterm birth. The aim of this study was to assess the screening performance of PlGF, soluble fms-like tyrosine kinase-1 (sFlt-1), N-terminal pro-brain natriuretic peptide (NT-proBNP), uric acid, and high-sensitivity cardiac troponin T (hs-TnT) in the prediction of adverse obstetric outcomes related to placental insufficiency. This retrospective case-control study was based on a cohort of 1390 pregnant women, among which 210 presented pre-eclampsia, small for gestational age infants, or preterm birth. Two hundred and eight women with healthy pregnancies were selected as controls. Serum samples were collected between weeks 9 and 13 of gestation, and maternal serum concentrations of PlGF, sFlt-1, NT-proBNP, uric acid, and hs-TnT were measured. Multivariate regression analysis was used to generate predictive models combining maternal factors with the above-mentioned biomarkers. Women with placental dysfunction had lower median concentrations of PlGF (25.77 vs. 32.00 pg/mL; p < 0.001), sFlt-1 (1212.0 vs. 1363.5 pg/mL; p = 0.001), and NT-proBNP (51.22 vs. 68.71 ng/L; p < 0.001) and higher levels of uric acid (193.66 µmol/L vs. 177.40 µmol/L; p = 0.001). There was no significant difference between groups regarding the sFlt-1/PlGF ratio. Hs-TnT was not detected in 70% of the maternal serums analyzed. Altered biomarker concentrations increased the risk of the analyzed complications both in univariate and multivariate analyses. The addition of PlGF, sFlt-1, and NT-proBNP to maternal variables improved the prediction of pre-eclampsia, small for gestational age infants, and preterm birth (area under the curve: 0.710, 0.697, 0.727, and 0.697 vs. 0.668, respectively). Reclassification improvement was greater in maternal factors plus the PlGF model and maternal factors plus the NT-p roBNP model (net reclassification index, NRI: 42.2% and 53.5%, respectively). PlGF, sFlt-1, NT-proBNP, and uric acid measurements in the first trimester of pregnancy, combined with maternal factors, can improve the prediction of adverse perinatal outcomes related to placental dysfunction. In addition to PlGF, uric acid and NT-proBNP are two promising predictive biomarkers for placental dysfunction in the first trimester of pregnancy.

Investigating a possible causal relationship between maternal serum urate concentrations and offspring birthweight: a Mendelian randomization study

BACKGROUND

Higher urate levels are associated with higher systolic blood pressure (SBP) in adults, and in pregnancy with lower offspring birthweight. Mendelian randomization (MR) analyses suggest a causal effect of higher urate on higher SBP and of higher maternal SBP on lower offspring birthweight. If urate causally reduces birthweight, it might confound the effect of SBP on birthweight. We therefore tested for a causal effect of maternal urate on offspring birthweight.

METHODS

We tested the association between maternal urate levels and offspring birthweight using multivariable linear regression in the Exeter Family Study of Childhood Health (EFSOCH; n = 872) and UK Biobank (UKB; n = 133 187). We conducted two-sample MR to test for a causal effect of maternal urate [114 single-nucleotide polymorphisms (SNPs); n = 288 649 European ancestry] on offspring birthweight (n = 406 063 European ancestry; maternal SNP effect estimates adjusted for fetal effects). We assessed a causal relationship between urate and SBP using one-sample MR in UKB women (n = 199 768).

RESULTS

Higher maternal urate was associated with lower offspring birthweight with similar confounder-adjusted magnitudes in EFSOCH [22 g lower birthweight per 1-SD higher urate (95% CI: -50, 6); P = 0.13] and UKB [-28 g (95% CI: -31, -25); P = 1.8 × 10-75]. The MR causal effect estimate was directionally consistent, but smaller [-11 g (95% CI: -25, 3); PIVW = 0.11]. In women, higher urate was causally associated with higher SBP [1.7 mmHg higher SBP per 1-SD higher urate (95% CI: 1.4, 2.1); P = 7.8 × 10-22], consistent with that previously published in women and men.

CONCLUSION

The marked attenuation of the MR result of maternal urate on offspring birthweight compared with the multivariable regression result suggests previous observational associations may be confounded. The 95% CIs of the MR result included the null but suggest a possible small effect on birthweight. Maternal urate levels are unlikely to be an important contributor to offspring birthweight.

Association of first trimester serum uric acid with preeclampsia: an observational cohort study with propensity score matching

To elucidate whether uric acid changes in early pregnancy are associated with the development of preeclampsia and their association with preeclampsia-related adverse pregnancy outcomes. We conducted a retrospective cohort study of 4725 singleton pregnant women between January 2017 and July 2019 using propensity score matching. The primary outcome of the cohort was preeclampsia, and the secondary outcomes were preterm delivery, preterm preeclampsia and low birth weight infants. Multivariable predicted marginal proportions from logistic regression models were used to compute adjusted risk ratios. The quantitative-effect relationship between serum uric acid and preeclampsia development was observed by a dose‒response graph, and the effect of serum uric acid on the week of gestation at delivery was assessed using the Kaplan‒Meier method and the log-rank test. The risk of preeclampsia development increased with higher serum uric acid levels. After adjusting for confounders, the risk ratio for the development of preeclampsia with uric acid levels ≥240 µmol/l was 1.25 (95% CI: 0.96-1.65) compared with the group with uric acid levels <240 µmol/l. In the subgroup analysis of KM (Kaplan-Meier) curves, the gestational week at delivery was earlier when uric acid levels ≥240 µmol/l occurred at 8-12 weeks of gestation. Elevated serum uric acid levels before 20 weeks of gestation are associated with the development of preeclampsia, especially in the first 8-12 weeks of gestation, and the effect is attenuated with increasing gestational weeks, which suggests that elevated uric acid levels in early pregnancy may be a causative factor in preeclampsia. Elevated serum uric acid levels before 20 weeks of gestation are associated with the development of preeclampsia, especially in the early 8-12 weeks of gestation, and the effect attenuates with increasing gestational weeks, which suggest that elevated uric acid in early pregnancy may be a causative factor in preeclampsia.

Association between maternal serum uric acid and preeclampsia

OBJECTIVE

The aim of this study is to compare the changes in serum uric acid levels among preeclamptic pregnant women and healthy pregnant women.

METHODS

Two hundred and twenty-four (224) pregnant women were enrolled. Serum uric acid levels were analysed in the two groups at the time of referral and prior to the delivery.

RESULTS

The mean uric acid in all pregnant women was 5.61 mg/dL. The mean uric acid in women with preeclampsia was 6.51 ± 1.53 and in normotensive women was 4.72 ± 1.58, which was seen significant. The mean age of the mother, gestational age and BMI were not significant with the levels of uric acid. The elevation in serum levels of uric acid increased the risk of preeclampsia by 1.98 folds.

CONCLUSION

There is a significant increase in the serum levels of uric acid in pregnant women with preeclampsia as compared to normotensive women. This can be one of a significant indicator of preeclampsia.

Relationship between maternal serum uric acid level and preeclampsia with or without severe features

Hyperuricaemia is common in preeclampsia. Its relationship and the utility in predicting of preeclampsia must be evaluated. The objective was to determine the association between maternal serum uric acid level and preeclampsia with or without severe features, including maternal and neonatal outcomes. A retrospective study was conducted at Rajavithi Hospital between June 2015 and May 2019. Inferential analysis comparison using binary logistic regression analysis and correlation using Chi-Square test/Fisher's exact test were used for analysis. Among the 400 participants, 331 (82.7%) women were preeclampsia with severe features. The mean uric acid level was significantly higher in women with preeclampsia with severe features compared to those without (6.44 ± 1.44 vs 5.87 ± 1.53 mg/dL, p-value = .016). Uric acid greater than 7 mg/dL was associated with renal involvement and preeclampsia with severe features. Uric acid 5-7 and greater than 7 mg/dL correlated with preterm birth (OR 2.67, 95% CI 1.59-4.49 and OR 4.89, 95% CI 2.75-8.68, respectively). Uric acid greater than 7 mg/dL also increased the risk of RDS and NICU admission. In conclusion, a high uric acid level is associated with preeclampsia with severe features and adverse pregnancy outcomes and may be the predictor of the severity of preeclampsia.Impact statementWhat is already known on this subject? Hyperuricaemia is a common finding in preeclamptic pregnancy due to reduction of uric acid clearance secondary to reduced glomerular filtration rate, increased reabsorption, and decreased secretion. The correlation of increase maternal uric acid level and preeclampsia including adverse pregnancy outcomes has been evaluated and supported the use of uric acid as a predictor for preeclampsia development. However, its clinical utility is still debateable.What the results of this study add? The present study demonstrated the association between higher maternal serum uric acid level and severity of preeclampsia. Particularly, serum uric acid greater than 7 mg/dL was associated with preeclampsia with severe features. Additionally, serum uric acid level 5-7 mg/dL and greater than 7 mg/dL had a positive correlation with adverse maternal and neonatal outcomes.What the implications are of these findings for clinical practice and/or further research? Maternal serum uric acid may be used as the predictor of severity of preeclampsia. However, the sensitivity and specificity and the precise clinical utility of uric acid related to preeclampsia need to be further evaluated in larger sample size.

Factors Involved in Endothelial Dysfunction Related to Angiogenic Disbalance and Oxidative Stress, in Women at High Risk of Term Pre-Eclampsia

Oxidative and inflammatory stress, angiogenic imbalance, and endothelial dysfunction are pathophysiological mechanisms occurring in pre-eclampsia (PE) that may persist over time and predispose women to a higher risk of cardiovascular disease (CVD) in the future. However, there is little evidence on the vascular function of women at risk of PE who have not developed the disease. The main objective of this research is to study factors and biomarkers involved in endothelial dysfunction related to oxidative stress, angiogenic disbalance, and inflammation in women at high risk of term PE who do not develop the disease. An observational, analytical, retrospective, and descriptive study was carried out in a selected sample of 68 high-risk and 57 non-risk of term PE participants in the STATIN study (FFIS/2016/02/ST EUDRACT No: 2016-005206-19). A significant increase in mean arterial pressure (MAP) levels and oxidative stress biomarkers (uric acid, homocysteine, and total serum antioxidant capacity) was found. Biomarkers of inflammation (interleukin-6 and growth differentiation factor 15) and endothelial function (asymmetric dimethylarginine) were significantly elevated in the group at risk of pre-eclampsia. A significative dependence relationship was also established between MAP and interleukin-6 and uric acid. These results suggest that women at high risk of term PE may represent pregnancies with pre-existing maternal risk factors for CVD, manifested by the own cardiovascular overload of pregnancy. A better understanding of maternal cardiovascular function in pregnancy would allow the improved prediction of CVD late in life in women.

Development and Validation of Multi-Stage Prediction Models for Pre-eclampsia: A Retrospective Cohort Study on Chinese Women

Objective

The aim of this study is to develop multistage prediction models for pre-eclampsia (PE) covering almost the entire pregnancy period based on routine antenatal measurements and to propose a risk screening strategy.

Methods

This was a retrospective cohort study that included 20582 singleton pregnant women with the last menstruation between January 1, 2013 and December 31, 2019. Of the 20582 women, 717 (3.48%) developed pre-eclampsia, including 46 (0.22%) with early-onset pre-eclampsia and 119 (0.58%) preterm pre-eclampsia. We randomly divided the dataset into the training set (N = 15665), the testing set (N = 3917), and the validation set (N = 1000). Least Absolute Shrinkage And Selection Operator (LASSO) was used to do variable selection from demographic characteristics, blood pressure, blood routine examination and biochemical tests. Logistic regression was used to develop prediction models at eight periods: 5-10 weeks, 11-13 weeks, 14-18 weeks, 19-23 weeks, 24-27 weeks, 28-31 weeks, 32-35 weeks, and 36-39 weeks of gestation. We calculated the AUROC (Area Under the Receiver Operating Characteristic Curve) on the test set and validated the screening strategy on the validation set.

Results

We found that uric acid tested from 5-10 weeks of gestation, platelets tested at 18-23 and 24-31 weeks of gestation, and alkaline phosphatase tested at 28-31, 32-35 and 36-39 weeks of gestation can further improve the prediction performance of models. The AUROC of the optimal prediction models on the test set gradually increased from 0.71 at 5-10 weeks to 0.80 at 24-27 weeks, and then gradually increased to 0.95 at 36-39 weeks of gestation. At sensitivity level of 0.98, our screening strategy can identify about 94.8% of women who will develop pre-eclampsia and reduce about 40% of the healthy women to be screened by 28-31 weeks of pregnancy.

Conclusion

We developed multistage prediction models and a risk screening strategy, biomarkers of which were part of routine test items and did not need extra costs. The prediction window has been advanced to 5-10 weeks, which has allowed time for aspirin intervention and other means for PE high-risk groups.

Hypertensive Disorders of Pregnancy: Common Clinical Conundrums

Importance

Hypertensive complications of pregnancy comprise 16% of maternal deaths in developed countries and 7.4% of deaths in the United States. Rates of preeclampsia increased 25% from 1987 to 2004, and rates of severe preeclampsia have increased 6.7-fold between 1980 and 2003.

Objective

The aim of this study was to review current and available evidence for common clinical questions regarding the management of hypertensive disorders of pregnancy.

Evidence Acquisition

Original research articles, review articles, and guidelines on hypertension in pregnancy were reviewed.

Results

Severe gestational hypertension should be managed as preeclampsia with severe features. Serum uric acid levels can be useful in predicting development of superimposed preeclampsia for women with chronic hypertension. When presenting with preeclampsia with severe features before 34 weeks, expectant management should be considered only when both maternal and fetal conditions are stable. In the setting of hypertensive disorders of pregnancy, oral antihypertensive medications should be initiated when systolic blood pressure is greater than 160 mm Hg or when diastolic blood pressure is greater than 110 mm Hg, with the most ideal agents being labetalol or nifedipine. Furthermore, although risk of preeclampsia recurrence in future pregnancy is low, women with a history of preeclampsia should be managed with 81 mg aspirin daily for preeclampsia prevention.

Conclusions and Relevance

Despite the frequency with which hypertensive disorders of pregnancy are encountered clinically, situations arise frequently with limited evidence to guide providers in their management. An urgent need exists to better understand this disease to optimize outcomes for impacted patients.

Reproductive Issues and Pregnancy Implications in Systemic Sclerosis

Systemic sclerosis (SSc) is a rare systemic autoimmune disease that can influence reproductive health. SSc has a strong female predominance, and the disease onset can occur during fertility age in almost 50% of patients. Preconception counseling, adjustment of treatment, and close surveillance during pregnancy by a multidisciplinary team, are key points to minimize fetal and maternal risks and favor successful pregnancy outcomes. The rates of spontaneous pregnancy losses are comparable to those of the general obstetric population, except for patients with diffuse cutaneous SSc and severe internal organ involvement who may carry a higher risk of abortion. Preterm birth can frequently occur in women with SSc, as it happens in other rheumatic diseases. Overall disease activity generally remains stable during pregnancy, but particular attention should be paid to women with major organ disease, such as renal and cardiopulmonary involvement. Women with such severe involvement should be thoroughly informed about the risks during pregnancy and possibly discouraged from getting pregnant. A high frequency of sexual dysfunction has been described among SSc patients, both in females and in males, and pathogenic mechanisms of SSc may play a fundamental role in determining this impairment. Fertility is overall normal in SSc women, while no studies in the literature have investigated fertility in SSc male patients. Nevertheless, some considerations regarding the impact of some immunosuppressive drugs should be done with male patients, referring to the knowledge gained in other rheumatic diseases.

Assessing the Role of Uric Acid as a Predictor of Preeclampsia

We assessed the diagnostic utility of uric acid for the prediction of preeclampsia. An observational prospective approach was carried out during 2014. Preeclamptic women were classified into 4 groups accordingly to the onset of preeclampsia and the presence of intrauterine growth restriction (IUGR). Serum uric acid levels, urea, and creatinine were measured. Receiver operating curves (ROC) of the uric acid levels ratio (UAr) between a dosage before and after the 20th week of gestation were performed. One thousand two hundred and ninety-third pregnant women were enrolled in this study. Eight hundred ten had non-complicated pregnancies, 40 preeclampsia, 33 gestational hypertension, and 20 IUGR without preeclampsia. Uric acid significantly raised after 20 weeks of gestation in women who develop preeclampsia before 34 weeks (Group A) or in those who develop preeclampsia after 37 weeks associated with IUGR (Group C). In women who develop preeclampsia after 34 weeks without IUGR (Groups B and D), uric acid increased after the 30th week of gestation. In all groups, UAr was greater than 1.5. In gestational hypertension, UAr was superior to 1.5 toward the end of gestation, while in IUGR without preeclampsia, the behavior of serum uric acid was similar to non-complicated pregnancies. In all cases, urea and creatinine showed normal values, confirming that patients had no renal compromise. ROC area was 0.918 [95% confidence interval (CI): 0.858–0.979) for the preeclampsia group and 0.955 (95% CI: 0.908–1.000) for Group A. UAr at a cut-off point ≥1.5 had a very low positive predictive value, but a high negative predictive value of 99.5% for preeclampsia and it reached 100% for Group A. Thus, a UAr less than 1.5 may be a helpful parameter with a strong exclusion value and high sensitivity for those women who are not expected to develop preeclampsia. Additionally, this low-cost test would allow for better use of resources in developing countries.

Serum uric acid levels associated with biochemical parameters linked to preeclampsia severity and to adverse perinatal outcomes

AIMS

Evaluating the association between serum uric acid levels and biochemical parameters linked to preeclampsia (PE) severity and to adverse perinatal outcomes.

METHODS

Cross-sectional study. Information about gestational and biochemical parameters were collected before delivery, whereas perinatal outcomes were observed after it. Pregnant women were divided into hyperuricemia-HU (uric acid ≥ 6 mg/dL) or normouricemia (uric acid, 2.6-5.9 mg/dL) groups. Poisson regression models (prevalence ratio-PR; 95% confidence interval-95% CI), multinomial logistic regression (odds ratio-OR; 95% CI), and Pearson's correlation (correlation coefficient-r) were applied by taking into consideration p < 0.05 as significance level.

RESULTS

The total sample comprised 267 pregnant women with PE. HU was observed in 25.8% of patients; it was associated with black pregnant women (p = 0.014) and with primiparity (p = 0.007). Uric acid levels were higher in early PE cases than in late PE cases (p = 0.013); however, there was no significant difference between mild and severe PE cases (p = 0.121). Uric acid recorded a positive correlation to urea (p < 0.001), creatinine (p = 0.002), glutamic-oxaloacetic transaminase (p < 0.001), glutamic-pyruvic transaminase (p = 0.005), ferritin (p = 0.002) and globulin (p = 0.002); as well as negative correlation to platelets (p = 0.035), lactic dehydrogenase (p = 0.039) and albumin (p > 0.001). HU was a factor associated with cesarean delivery (p = 0.030), prematurity (p = 0.001), low birth weight (p < 0.001) and small for gestational age (p = 0.020).

CONCLUSION

High serum uric acid levels were associated with early-onset PE. Maternal features were correlated to biochemical parameters linked to PE severity and to adverse perinatal outcomes.

Characterizing and Evaluating Diurnal Salivary Uric Acid Across Pregnancy Among Healthy Women

Uric acid levels during pregnancy have been examined as a potential indicator of risk for gestational diabetes mellites, hypertension, and related adverse birth outcomes. However, evidence supporting the utility of serum uric acid levels in predicting poor maternal and fetal health has been mixed. The lack of consistent findings may be due to limitations inherent in serum-based biomeasure evaluations, such as minimal repeated assessments and variability in the timing of these assessments. To address these gaps, we examined repeated measurements of diurnal salivary uric acid (sUA) levels in a sample of 44 healthy women across early-mid and late pregnancy. We assessed potential covariates and confounds of sUA levels and diurnal trajectories, as well as associations between maternal weight gain and blood pressure during pregnancy and sUA concentrations. Using multilevel linear models, we found sUA increased across pregnancy and displayed a robust diurnal pattern with the highest concentrations at waking, a steep decline in the early morning, and decreasing levels across the day. Maternal pre-pregnancy BMI, age, prior-night sleep duration, and fetal sex were associated with sUA levels and/or diurnal slopes. Maternal blood pressure and gestational weight gain also showed significant associations with sUA levels across pregnancy. Our results expand upon those found with serum UA measurements. Further, they demonstrate the feasibility of using at-home, minimally-invasive saliva sampling procedures to track UA levels across pregnancy with potential applications for the long-term monitoring of maternal cardiometabolic risk.

The role of cystatin C, neutrophil-lymphocyte ratio and platelet-lymphocyte ratio in the evaluation of kidney function in women with preeclampsia

OBJECTIVE

We aimed to compare the diagnostic efficiency of cystatin C with traditional kidney markers in preeclampsia and to evaluate the relationship of these markers with neutrophil-lymphocyte and thrombocyte-lymphocyte ratios.

MATERIALS AND METHODS

14 severe preeclampsia, 48 mild preeclampsia and 79 patients with healthy pregnancy who presented to our obstetrics and gynecology clinic within one year were compared. These three groups were compared in terms of demographic characteristics, physical findings, serum urea, creatinine, cystatin C levels, and neutrophil-lymphocyte and platelet-lymphocyte ratios.

RESULTS

The mean serum cystatin C, creatinine and uric acid levels were higher in the severe preeclampsia group compared with the mild preeclamptic and healthy pregnancies (p < 0.001). While cystatin C values increased as the week of gestation increased in the mild preeclampsia group, there was no relation with the gestational week in the control group and the severe preeclampsia group. However, the highest cystatin C values were in the severe preeclampsia group, regardless of the week (p < 0.05). The area under the ROC curve was statistically significant for cystatin C, uric acid and creatinine, but of these three values, cystatin C had the highest sensitivity and specificity. Neutrophil-lymphocyte ratio (NLR) was significantly higher in the severe preeclampsia group than healthy pregnancies, but the level was not significant compared to mild preeclampsia. There was no difference between the groups in terms of platelet-lymphocyte ratio.

CONCLUSION

It can be suggested that cystatin C level reflects renal functions better than uric acid and creatinine in preeclampsia. Cystatin C can be used as a prognostic marker in preeclamptic pregnancies, and rising levels may be valuable for predicting severe preeclampsia. Especially with advancing gestational week, the increase in cystatin C level may indicate an association with the development of preeclampsia. NLR levels may be a parameter correlating with severity in severe preeclampsia.

Interleukin-1β and uric acid as potential second-trimester predictive biomarkers of preeclampsia

Methods: The prospective study was conducted at the University Hospital from February 2020 to December 2020. The study population (n = 88) included women who later developed PE (n = 42), as well as women who were healthy at birth (n = 46) in the second trimester of pregnancy. Serum levels of CRP, IL-1β, uric acid, creatinine, AST, ALT, MPV, Hb, PC, vitamin D, Ca, and Mg were compared between the groups.Results: Serum IL-1β and uric acid levels were significantly higher in subjects who eventually developed PE compared with those who did not.Conclusions: IL-1β and uric acid may be a predictive markers for PE. Maternal serum IL-1β and uric acid levels in the second trimester of pregnancy may be a predictive markers for PE.

Uric acid participating in female reproductive disorders: a review

Uric acid (UA) is the end metabolic product of purine metabolism. Early on, UA was considered to be a metabolite with a certain antioxidant capacity. As research has progressed, other properties of UA have been explored, and its association with many diseases has been found. The association between UA and kidney disease and cardiovascular disease is well established; however, there is still a paucity of reviews on the association between UA and the female reproductive system. An increasing number of epidemiological studies have shown elevated serum UA levels in patients with polycystic ovary syndrome (PCOS), endometriosis, etc. Additionally, serum UA can be used as a predictor of pregnancy complications and adverse foetal outcomes. An increasing number of animal experiments and clinical studies have revealed possible mechanisms related to the involvement of UA in certain female reproductive disorders: oxidative stress, chronic inflammation, mitochondrial dysfunction, etc. This article reviews the current mainstream mechanisms regarding the pathogenesis of UA and the role of UA in certain specific female reproductive disorders (direct involvement in the development of certain diseases or enhancement of other risk factors) in the hope of contributing to clinical prevention, diagnosis, treatment and improvement in prognosis.

Uric Acid and Cardiovascular Disease: An Update From Molecular Mechanism to Clinical Perspective

Uric acid (UA) is the end product of purine nucleotide metabolism in the human body. Hyperuricemia is an abnormally high level of UA in the blood and may result in arthritis and gout. The prevalence of hyperuricemia has been increasing globally. Epidemiological studies have shown that UA levels are positively correlated with cardiovascular diseases, including hypertension, atherosclerosis, atrial fibrillation (AF), and heart failure (HF). Hyperuricemia promotes the occurrence and development of cardiovascular diseases by regulating molecular signals, such as inflammatory response, oxidative stress, insulin resistance/diabetes, endoplasmic reticulum stress, and endothelial dysfunction. Despite extensive research, the underlying molecular mechanisms are still unclear. Allopurinol, a xanthine oxidase (XO) inhibitor, has been shown to improve cardiovascular outcomes in patients with HF, coronary heart disease (CHD), type 2 diabetes (T2D), and left ventricular hypertrophy (LVH). Whether febuxostat, another XO inhibitor, can improve cardiovascular outcomes as well as allopurinol remains controversial. Furthermore, it is also not clear whether UA-lowering treatment (ULT) can benefit patients with asymptomatic hyperuricemia. In this review, we focus on the latest cellular and molecular findings of cardiovascular disease associated with hyperuricemia and clinical data about the efficacy of ULT in patients with cardiovascular disease.

Progress in deciphering trophoblast cell differentiation during human placentation

The maintenance of gestational well-being requires the proper development of both the embryo and the placenta. Placental trophoblast cells are the major building blocks of the developing placenta. Abnormal trophoblast differentiation underpins placental-based pregnancy complications. However, the mechanisms that govern trophoblast differentiation remain largely unclear. Recent studies shed light on several proteins and regulators that are involved in governing trophoblast differentiation. The advancement of new tools and novel technologies, such as the human trophoblast stem cell culture system, 3D placental organoids and single-cell multi-omics, has brought incredible insights to the field. Here we review the current literature, paying particular attention to articles published between 2017 and 2019 that have promoted our understanding of human trophoblast cell differentiation and its roles in pregnancy and its complications. At the same time, we address challenges and questions arising in the field of human placental development and disease.

Predictive value of serum uric acid levels for adverse maternal and perinatal outcomes in pregnant women with high blood pressure. A systematic review and meta-analysis

OBJECTIVE

High serum uric acid seems to be associated with pre-eclampsia. The expected utility of uric acid is related to the probability of occurrence of maternal and neonatal complications. We evaluated the accuracy of uric acid in predicting adverse maternal and perinatal outcomes in pregnant women with high blood pressure.

METHODS

We performed an electronic search for studies evaluating the accuracy of high serum uric acid levels in pregnant women with high blood pressure. The assessment of risk of bias was performed using the QUIPS tool. For each included study, we collected data about study characteristics and diagnostic test accuracy to construct 2 × 2 tables. Pooled sensitivity (Se), specificity (Sp) and diagnostic odds ratio (DOR) were estimated using a bivariate model. Grading the quality of the evidence was assessed using the GRADE approach.

RESULTS

Twenty-one studies, testing more than 6,000 women, met the inclusion criteria. The majority of studies were at low risk of bias. Ten studies evaluated the role of serum uric acid to predict pre-eclampsia, the pooled Se was 0.74 (95%CI 0.71-0.77), Sp was 0.66 (95%CI 0.63-0.68), and DOR was 9.67 (95%CI 4.57-20.47). The overall quality of evidence was evaluated as low. The GRADE rating was downgraduate for risk of bias and inconsistency.

CONCLUSIONS

No robust evidence currently exists to suggest that uric acid measurement is useful in predicting maternal and perinatal adverse outcomes.

Lipid profile and lipid oxidative modification parameters in the first trimester of high- risk pregnancies - possibilities for preeclampsia prediction

OBJECTIVES

The goal of this study was to investigate metabolic changes in lipids and oxidative stress parameters in the first trimester of pregnancy with the more specific aim of estimating the significance and strength of researched parameters in the prediction of preeclampsia.

DESIGN AND METHODS

The study included 87 high-risk pregnant (HRG) female subjects, 14 with developed preeclampsia (PEC) and 43 healthy pregnant female subjects matched for gestational age (CG). Thiobarbituric acid-reactive substances (TBARS) concentration, lipid hydroperoxides (LOOH), pro-oxidant antioxidant balance (PAB) and total oxidative status (TOS) were measured as oxidative stress markers, while total antioxidant capacity (TAC) was measured as an antioxidative defense parameter. The Atherogenic Index of Plasma (AIP) was calculated as the base 10 logarithm of the ratio of the plasma concentration of triglycerides (TG) to the plasma concentration of high-density lipoprotein cholesterol (HDL-C), with each concentration expressed in mmol/L.

RESULTS

The results have shown that lipid indices, especially AIP, were significantly higher in the first trimester of HRG (p < 0.001) and PEC (p < 0.001). Oxidative stress parameters were significantlly higher, while TAC was significantly lower in HRG vs. CG [0.7 ± 0.15 vs 1.1 ± 0.16; (p < 0.001)] and in PEC [0.6 ± 0.12 vs 1.1 ± 0.16; (p < 0.001)] vs. CG. Also, in the HRG, results have shown an independent association of AIP with the preeclampsia development (p < 0.05), while placental growth factor did not show the expected level of significance (p = 0.648). Analysis of the Receiver Operating Characteristics (ROC) curves indicated that certain parameters included in the research model have very good diagnostic accuracy for preeclampsia (AUC = 0.856).

CONCLUSIONS

AIP is associated with high-risk pregnancies. Furthermore, our results firmly underscored AIP as a potential marker for preeclampsia prediction.

The prognostic role of serum uric acid levels in preeclampsia: A meta-analysis

This meta-analysis aims to compare serum uric acid levels among preeclamptic and healthy pregnant women across the various trimesters and provide a summary of the effect size of this biomarker in predicting adverse pregnancy outcomes. MEDLINE, Scopus, CENTRAL, Clinicaltrials.gov, and Google Scholar databases were systematically searched from inception. Observational studies were held eligible if they reported serum uric acid among preeclamptic and healthy pregnant women. Meta-analysis was conducted regarding uric acid concentration, diagnostic accuracy, and association with perinatal outcomes. The credibility of evidence was appraised using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework. The analysis included 196 studies, comprising 39 540 women. Preeclampsia was associated with significantly elevated uric acid levels during the 1st (mean difference [MD]: 0.21 mg/dL, 95% confidence intervals [CI]: 0.06-0.35) trimester, 2nd (MD: 1.41 mg/dL, 95% CI: 0.78-2.05) trimester, and 3rd (MD: 2.26 mg/dL, 95% CI: 2.12-2.40) trimester. Higher uric acid was estimated for severe preeclampsia, eclampsia, and hemolysis, elevated liver enzymes, low platelet syndrome. The sensitivity for adverse perinatal outcome prediction ranged from 67.3% to 82.7% and the specificity from 47.7% to 70.7%. In conclusion, it is suggested that serum uric acid levels are increased in preeclampsia and can be used to predict disease severity and pregnancy complications. Future prospective studies should verify these outcomes, assess the optimal cutoffs, and incorporate uric acid to combined predicting models.

Serum Uric Acid Measurement in Women With Hypertensive Disorders of Pregnancy

A 27-year-old asymptomatic primigravid woman at 36 weeks of gestation is evaluated in the labor and delivery unit with new-onset hypertension of 145/92 mm Hg (with similar measurements 4 hours apart). A spot urine protein/creatinine ratio is 0.35, serum transaminases and creatinine level are normal, and uric acid is 6.0 mg/dL (upper limit of normal for adult woman is 6.0 mg/dL but typically 4-5 mg/dL in the third trimester). Antenatal fetal testing and growth on ultrasound scan are reassuring. She is discharged for home management and ultimately delivered at 37 weeks of gestation for preeclampsia without severe features.

Placenta-specific plasma miR518b is a potential biomarker for preeclampsia

INTRODUCTION

MicroRNAs have a significant role in the pathogenesis of preeclampsia. Circulating microRNAs could represent a potential biomarker for preeclampsia. The aim of this study was to evaluate plasma miR210-3p and miR518b in preeclampsia and healthy pregnancy for the first time by digital droplet PCR (ddPCR).

METHODS

Thirty-six pregnant women (seventeen healthy pregnancies, nineteen preeclampsia patients) were involved from the Clinic for Gynaecology and Obstetrics "Narodni front" in Belgrade, Serbia. Plasma miR210-3p, miR518b and cel-miR-39 as a spike-in control were measured by ddPCR.

RESULTS

MiR518b was significantly elevated in preeclampsia compared to a healthy pregnancy (P = 0.034; 0.302(0.217-0.421) vs. 0.171(0.110-0.266)). MiR210-3p showed no significant difference between the two groups (P = 0.951). The adjustment of miR518b was made for a gestational age and smoking status and the difference between the preeclampsia and healthy pregnancy group was more significant (P = 0.026; 0.300(0.216-0.419) vs. 0.172(0.121-0.245)). Plasma miR-518b was significantly higher in the group of preeclampsia patients with proteinuria above the 75th percentile for the group (P = 0.033), in women who smoked (P = 0.039), and was positively related to uric acid in preeclampsia (P = 0.018, r = 0.536). Plasma miR518b was able to significantly discriminate between preeclampsia and healthy pregnancy, yielding AUC of 0.712 (95%CI:0.539-0.891), P = 0.028.

CONCLUSIONS

In this study plasma microRNA were measured for the first time in preeclampsia and healthy pregnancies with ddPCR. Placenta-specific miR-518b could serve as a potential biomarker for discriminating preeclampsia and healthy pregnancy, which should be confirmed on a larger study population. This study has failed to confirm the same potential for miR210-3p.

Value of ABCG2 Q141K and Q126X genotyping in predicting risk of preeclampsia in Chinese Han women population

Hyperuricemia (HUA) in women with preeclampsia (PE) not only indicates a reminder of severity but also contributes directly to the pathogenesis of PE. ATP-binding cassette subfamily G member 2 (ABCG2) has a very strong effect on the serum urate concentrations. Our aim was to investigate the association between polymorphisms of ABCG2 with PE in Chinese Han female population. A cohort of 793 preeclamptic women (466 PE with HUA and 327 PE without HUA) and 744 normal pregnant women recruited in this study were genotyped for genetic distribution of Q141K (rs2231142) and Q126X (72552713) in ABCG2 by the TaqMan allelic discrimination real-time PCR. There was no statistically significant difference of genotypic and allelic frequencies between PE and the normal pregnant women in Q141K (Χ² = 1.11, P = 0.58 by genotype; Χ² = 0.32, P = 0.57 by allele) and Q126X (P = 0.33 by genotype; P = 0.33 by allele), and no significant difference was found in the genetic distribution of Q141K and Q126X between PE with HUA, PE without HUA and controls. Additionally, this study observed no significant difference in genotypic and allelic distribution between early/late-onset PE with/without HUA or mild/severe PE with/without HUA and control subgroups. Based on our findings, the ABCG2 Q141K and Q126X polymorphisms may not be associated with PE in Chinese Han women.