Plasma uric acid remains a marker of poor outcome in hypertensive pregnancy: a retrospective cohort study

Elevated uric acid in gestational diabetes and its risk on pregnancy outcomes

Background

Over the past few years, gestational diabetes mellitus has become more common. According to earlier research, gestational diabetes mellitus is linked to higher uric acid levels, and gestational hyperuricemia is linked to poor maternal and neonatal outcomes.

Aim and objectives

To assess the influence of elevated uric acid >5 mg/dl on pregnancy outcomes such as neonatal weight, respiratory distress, preterm delivery, neonatal intensive care unit admission, premature membrane rupture, oligohydramnios, cesarean section, and intensive care admission for mothers.

Setting and methods

It is a prospective cohort study, carried out at obstetric/family medicine outpatient clinics, Cairo University Hospitals on 221 pregnant females with gestational diabetes mellitus in their third trimester of pregnancy, selected by random sampling, performed structured interviews, and tested for serum uric acid level and were separated into two groups, those with elevated uric acid >5 mg/dl (121) and those without elevated uric acid ⩽5 mg/dl (100) patients and then followed up until delivery in Cairo University Hospitals for collecting pregnancy outcome data.

Results

There were statistically significant differences between the antepartum uric acid and neonatal complications, maternal complications, preterm, macrosomia, neonatal intensive care unit admission, premature rupture of membranes, oligohydramnios, and cesarean section between both groups.

Conclusions

This study showed that elevated serum uric acid >5 mg/dl can predict the incidence of maternal and neonatal problems in gestational diabetes mellitus including preterm, macrosomia, neonatal intensive care unit admission, premature rupture of membranes, oligohydramnios, and cesarean section.

Preeclampsia epidemiology(ies) and pathophysiology(ies)

Preeclampsia/eclampsia was first described 2000 years ago. Concepts guiding diagnosis have changed over time making longitudinal studies challenging. Similarly, concepts of pathophysiology have evolved from eclampsia as a pregnancy seizure disorder to preeclampsia as a hypertensive and renal disorder to our current concept of a preeclampsia as a pregnancy specific, multisystemic inflammatory disorder. Although preeclampsia is pregnancy specific and many pathophysiologic findings begin to resolve with delivery, its impact extends beyond pregnancy. The risk of cardiovascular and neurological disease is increased after pregnancy in women who have had preeclampsia. The disorder is not a disease, but a syndrome and emerging data indicate multiple pathways to the syndrome. It is likely that our failure to have a major impact on prediction and prevention despite a large increase in understanding is due to the existence of multiple subtypes of preeclampsia. This concept should guide future research.

The association of hyperuricemia and maternal and fetal outcomes among pregnant women: a meta-analysis

OBJECTIVE

This meta-analysis aimed to investigate the relationship between hyperuricemia and maternal and neonatal complications in pregnant women.

METHODS

We searched PubMed, Embase, Web of Science, and the Cochrane Library from the databases' inception to August 12, 2022. We included studies that reported results on the association between hyperuricemia and maternal and fetal outcomes among pregnant women. Using the random-effects model, the pooled odds ratio (OR) with 95% confidence intervals (CIs) was calculated for each outcome analysis.

RESULTS

A total of 7 studies, including 8104 participants, were included. The pooled OR for pregnancy-induced hypertension (PIH) was 2.61 [0.26, 26.56] (z = 0.81, p = .4165; I² = 96.3%). The pooled OR for preterm birth was 2.52 [1.92, 3.30] (z = 6.64, p < .0001; I² = 0%). The pooled OR for low birth weight (LBW) was 3.44 [2.52, 4.70] (z = 7.77, p < .0001; I² = 0%). The pooled OR for small gestational age (SGA) was 1.81 [0.60, 5.46] (z = 1.06, p = .2912; I² = 88.6%).

CONCLUSION

Results of this meta-analysis indicate a positive relationship between hyperuricemia and PIH, preterm birth, LBW, and SGA in pregnant women.

Associations of early pregnancy serum uric acid levels with risk of gestational diabetes and birth outcomes: a retrospective cohort study

BACKGROUND

Previous evidence suggests that higher blood uric acid (UA) levels are associated with adverse cardiovascular outcomes during pregnancy and subsequent birth outcomes. However, it has been relatively unclear whether these associations persist in normotensive pregnant women.

METHODS

The study was based on a retrospective analysis of 18,250 mother-infant pairs in a large obstetric center in China. Serum UA concentrations in early pregnancy (median: 17.6, IQR: 16.3, 18.6 gestational weeks) were assessed. Hyperuricemia was defined as ≥ one standard deviation (SD) of the reference value for the corresponding gestational age. Outcomes of gestational diabetes mellitus (GDM), preterm birth (PB), low birth weight (LBW), macrosomia, small for gestational age (SGA) and large for gestational age (LGA) were extracted from the medical records.

RESULTS

The mean maternal UA level was 0.22 ± 0.05 mmol/L, and 2,896 (15.9%) subjects had hyperuricemia. After adjustment for several covariates, UA was associated with several adverse outcomes. The ORs (95%CI) per one SD increase in serum UA concentration were 1.250 (1.136, 1.277) for GDM, 1.137 (1.060, 1.221) for PB, 1.134 (1.051, 1.223) for LBW, and 1.077 (1.020, 1.137) for SGA, respectively. Similar adverse associations were found between hyperuricemia and GDM, PB (ORs: 1.394 and 1.385, P < 0.001), but not for LBW, macrosomia, SGA, and LGA. Adverse associations tended to be more pronounced in subjects with higher BMI for outcomes including PB, LBW, and SGA (P interaction = 0.001-0.028).

CONCLUSION

Higher UA levels in early pregnancy were associated with higher risk of GDM, PB, LBW, and SGA in normotensive Chinese women.

Metabolomic profiling of preterm birth in pregnant women living with HIV

BACKGROUND

Preterm birth is a leading cause of death in children under the age of five. The risk of preterm birth is increased by maternal HIV infection as well as by certain antiretroviral regimens, leading to a disproportionate burden on low- and medium-income settings where HIV is most prevalent. Despite decades of research, the mechanisms underlying spontaneous preterm birth, particularly in resource limited areas with high HIV infection rates, are still poorly understood and accurate prediction and therapeutic intervention remain elusive.

OBJECTIVES

Metabolomics was utilized to identify profiles of preterm birth among pregnant women living with HIV on two different antiretroviral therapy (ART) regimens.

METHODS

This pilot study comprised 100 mother-infant dyads prior to antiretroviral initiation, on zidovudine monotherapy or on protease inhibitor-based antiretroviral therapy. Pregnancies that resulted in preterm births were matched 1:1 with controls by gestational age at time of sample collection. Maternal plasma and blood spots at 23-35 weeks gestation and infant dried blood spots at birth, were assayed using an untargeted metabolomics method. Linear regression and random forests classification models were used to identify shared and treatment-specific markers of preterm birth.

RESULTS

Classification models for preterm birth achieved accuracies of 95.5%, 95.7%, and 80.7% in the untreated, zidovudine monotherapy, and protease inhibitor-based treatment groups, respectively. Urate, methionine sulfone, cortisone, and 17α-hydroxypregnanolone glucuronide were identified as shared markers of preterm birth. Other compounds including hippurate and N-acetyl-1-methylhistidine were found to be significantly altered in a treatment-specific context.

CONCLUSION

This study identified previously known as well as novel metabolomic features of preterm birth in pregnant women living with HIV. Validation of these models in a larger, independent cohort is necessary to ascertain whether they can be utilized to predict preterm birth during a stage of gestation that allows for therapeutic intervention or more effective resource allocation.

Elevated levels of renal function tests conferred increased risks of developing various pregnancy complications and adverse perinatal outcomes: insights from a population-based cohort study

OBJECTIVES

Physiological changes during pregnancy can affect the results of renal function tests (RFTs). In this population-based cohort study, we aimed to establish trimester-specific reference intervals (RIs) of RFTs in singleton and twin pregnancies and systematically investigate the relationship between RFTs and adverse pregnancy outcomes.

METHODS

The laboratory results of the first- and third-trimester RFTs, including blood urea nitrogen (BUN), serum uric acid (UA), creatinine (Crea) and cystatin C (Cys C), and the relevant medical records, were retrieved from 29,328 singleton and 840 twin pregnant women who underwent antenatal examinations from November 20, 2017 to January 31, 2021. The trimester-specific RIs of RFTs were estimated with both of the direct observational and the indirect Hoffmann methods. The associations between RTFs and pregnancy complications as well as perinatal outcomes were assessed by logistic regression analysis.

RESULTS

Maternal RFTs showed no significant difference between the direct RIs established with healthy pregnant women and the calculated RIs derived from the Hoffmann method. In addition, elevated levels of RFTs were associated with increased risks of developing various pregnancy complications and adverse perinatal outcomes. Notably, elevated third-trimester RFTs posed strong risks of preterm birth (PTB) and fetal growth restriction (FGR).

CONCLUSIONS

We established the trimester-specific RIs of RFTs in both singleton and twin pregnancies. Our risk analysis findings underscored the importance of RFTs in identifying women at high risks of developing adverse complications or outcomes during pregnancy.

Uric acid and risk of pre-eclampsia: results from a large case-control study and meta-analysis of prospective studies

To quantify the association between maternal uric acid levels and pre-eclampsia risk in a large collection of primigravid women. A case-control study (1365 cases of pre-eclampsia and 1886 normotensive controls) was conducted. Pre-eclampsia was defined as blood pressure ≥ 140/90 mmHg and proteinuria ≥ 300 mg/24 h. Sub-outcome analysis included early, intermediate, and late pre-eclampsia. Multivariable analysis for pre-eclampsia and its sub-outcomes was conducted using binary and multinomial logistic regression, respectively. Additionally, a systematic review and meta-analysis of cohort studies measuring uric acid levels < 20 weeks of gestation was performed to rule out reverse causation. There was a positive linear association between increasing uric acid levels and presence of pre-eclampsia. Adjusted odds ratio of pre-eclampsia was 1.21 (95%CI 1.11-1.33) for every one standard deviation increase in uric acid levels. No differences in the magnitude of association were observed between early and late pre-eclampsia. Three studies with uric acid measured < 20 weeks' gestation were identified, with a pooled OR for pre-eclampsia of 1.46 (95%CI 1.22-1.75) for a top vs. bottom quartile comparison. Maternal uric acid levels are associated with risk of pre-eclampsia. Mendelian randomisation studies would be helpful to further explore the causal role of uric acid in pre-eclampsia.

Predictive Model for Preeclampsia Combining sFlt-1, PlGF, NT-proBNP, and Uric Acid as Biomarkers

N-terminal pro-brain natriuretic peptide (NT-proBNP) and uric acid are elevated in pregnancies with preeclampsia (PE). Short-term prediction of PE using angiogenic factors has many false-positive results. Our objective was to validate a machine-learning model (MLM) to predict PE in patients with clinical suspicion, and evaluate if the model performed better than the sFlt-1/PlGF ratio alone. A multicentric cohort study of pregnancies with suspected PE between 24+0 and 36+6 weeks was used. The MLM included six predictors: gestational age, chronic hypertension, sFlt-1, PlGF, NT-proBNP, and uric acid. A total of 936 serum samples from 597 women were included. The PPV of the MLM for PE following 6 weeks was 83.1% (95% CI 78.5−88.2) compared to 72.8% (95% CI 67.4−78.4) for the sFlt-1/PlGF ratio. The specificity of the model was better; 94.9% vs. 91%, respectively. The AUC was significantly improved compared to the ratio alone [0.941 (95% CI 0.926−0.956) vs. 0.901 (95% CI 0.880−0.921), p < 0.05]. For prediction of preterm PE within 1 week, the AUC of the MLM was 0.954 (95% CI 0.937−0.968); significantly greater than the ratio alone [0.914 (95% CI 0.890−0.934), p < 0.01]. To conclude, an MLM combining the sFlt-1/PlGF ratio, NT-proBNP, and uric acid performs better to predict preterm PE compared to the sFlt-1/PlGF ratio alone, potentially increasing clinical precision.

Serum urea acid and urea nitrogen levels are risk factors for maternal and fetal outcomes of pregnancy: a retrospective cohort study

BACKGROUND

In recent years, results on the association between serum uric acid (UA) and pregnancy outcomes have been inconsistent, and the association between urea nitrogen (UN) and adverse pregnancy outcomes in normal pregnant women has not been reported. Thus, we examined the association of UA and UN levels during gestation with the risk of adverse pregnancy outcomes in a relatively large population.

METHODS

A total of 1602 singleton mothers from Union Shenzhen Hospital of Huazhong University of Science and Technology at January 2015 to December 2018 were included. Both UA and UN levels were collected and measured during the second (16-18th week) and third (28-30th week) trimesters of gestation respectively. Statistical analysis was performed using multivariate logistic regression.

RESULTS

After adjustment, the highest quartile of UA in the third trimester increased the risk of premature rupture of membranes (PROM) and small for gestational age infants (SGA) by 48% (odds ratio [OR]: 1.48, 95% confidence interval [CI]: 1.04-2.10) and 99% (95% CI: 1.01-3.89) compared to those in the lowest quartile. The adjusted OR (95% CI) in the highest quartile of UN for the risk of SGA was 2.18 (95% CI: 1.16-4.13) and 2.29 (95% CI: 1.20-4.36) in the second and third trimester, respectively. In the second trimester, when UA and UN levels were both in the highest quartile, the adjusted OR (95% CI) for the risk of SGA was 2.51 (95% CI: 1.23-5.10). In the third trimester, when the group 1 (both indicators are in the first quartile) was compared, the adjusted ORs (95% CI) for the risk of SGA were 1.98 (95% CI: 1.22-3.23) and 2.31 (95% CI: 1.16-4.61) for group 2 (UA or UN is in the second or third quartile) and group 3 (both indicators are in the fourth quartile), respectively.

CONCLUSIONS

Higher UA and UN levels increased the risk of maternal and fetal outcomes. The simultaneous elevation of UA and UN levels was a high-risk factors for the development of SGA, regardless of whether they were in the second or third trimester.

Evaluation of serum lipid profiles, uric acid, and high sensitivity C‐reactive protein levels between pregnancy‐induced hypertension and normotensive pregnant women attending Ambo University Referral Hospital, Ambo, Ethiopia, 2020: A case‐control study

Background and Aims

Pregnancy‐induced hypertension is one of the top three ranked diseases during pregnancy that cause maternal, fetal, and neonatal morbidity and mortality worldwide. To provide adequate information to clinicians and researchers who are striving for potential interventions, biochemical profiling of such patients is required.

Methods

A hospital‐based case‐control study design was conducted from August 2020 to May 2021 to evaluate serum lipid profile, uric acid, and high sensitivity C‐reactive protein (hs‐CRP) among women with pregnancy‐induced hypertension compared to normotensive pregnant women. Data were entered and analyzed using SPSS version 25. Independent t‐test and χ² were used to compare the relationship of variables between the two groups. A p‐value less than 0.05 was used to test statistical significance.

Results

The result of this study showed that while the levels (mean ± SD) of serum total cholesterol (TC), triglyceride (TG), low‐density lipoprotein‐cholesterol (LDL‐C), TC/high‐density lipoprotein‐cholesterol (HDL‐C), TG/HDL‐C, LDL‐C/HDL‐C were significantly elevated, HDL‐C was decreased among women with pregnancy‐induced hypertension than normotensive pregnant women (p < 0.0001). The levels (mean ± SD) of uric acid and hs‐CRP were significantly higher among women with pregnancy‐induced hypertension compared to normotensive pregnant women (p < 0.0001).

Conclusion

This study indicated that pregnancy‐induced hypertension women have lipid abnormalities, increased systemic inflammatory markers, and hyperuricemia compared to normotensive pregnant women. Thus, women with PIH showing high dyslipidemia, hyperuricemia, and inflammation are likely to develop hypertension. Therefore, evaluation of these potential biomarkers during early antenatal care services may help seek interventions in PIH.

Directive clinique no 426 : Troubles hypertensifs de la grossesse : Diagnostic, prédiction, prévention et prise en charge

OBJECTIF

La présente directive a été élaborée par des fournisseurs de soins de maternité en obstétrique et en médecine interne. Elle aborde le diagnostic, l'évaluation et la prise en charge des troubles hypertensifs de la grossesse, la prédiction et la prévention de la prééclampsie ainsi que les soins post-partum des femmes avec antécédent de trouble hypertensif de la grossesse.

POPULATION CIBLE

Femmes enceintes. BéNéFICES, RISQUES ET COûTS: La mise en œuvre des recommandations de la présente directive devrait réduire l'incidence des troubles hypertensifs de la grossesse, en particulier la prééclampsie, et des issues défavorables associées. DONNéES PROBANTES: La revue exhaustive de la littérature a été mise à jour en tenant compte des nouvelles données probantes jusqu'en décembre 2020 et en suivant la même méthodologie que pour la précédente directive de la Société des obstétriciens et gynécologues du Canada (SOGC) sur les troubles hypertensifs de la grossesse. La recherche s'est limitée aux articles publiés en anglais ou en français. Les recommandations relatives aux traitements s'appuient d'abord sur les essais cliniques randomisés et les revues systématiques (lorsque disponibles), ainsi que sur l'évaluation des résultats cliniques substantiels chez les mères et les bébés. MéTHODES DE VALIDATION: Les auteurs se sont entendus sur le contenu et les recommandations par consensus et ont répondu à l'examen par les pairs du comité de médecine fœto-maternelle de la SOGC. Les auteurs ont évalué la qualité des données probantes et la force des recommandations en utilisant le cadre méthodologique d'évaluation, de développement et d'évaluation (GRADE) et se sont gardé l'option de désigner certaines recommandations par la mention « bonne pratique ». Voir l'annexe A en ligne (tableau A1 pour les définitions et tableau A2 pour l'interprétation des recommandations fortes et conditionnelles [faibles]). Le conseil d'administration de la SOGC a approuvé la version définitive aux fins de publication.

PROFESSIONNELS CIBLES

Tous les fournisseurs de soins de santé (obstétriciens, médecins de famille, sages-femmes, infirmières et anesthésistes) qui prodiguent des soins aux femmes avant, pendant ou après la grossesse.

RECOMMANDATIONS

Guideline No. 426: Hypertensive Disorders of Pregnancy: Diagnosis, Prediction, Prevention, and Management

OBJECTIVE

This guideline was developed by maternity care providers from obstetrics and internal medicine. It reviews the diagnosis, evaluation, and management of the hypertensive disorders of pregnancy (HDPs), the prediction and prevention of preeclampsia, and the postpartum care of women with a previous HDP.

TARGET POPULATION

Pregnant women.

BENEFITS, HARMS, AND COSTS

Implementation of the recommendations in these guidelines may reduce the incidence of the HDPs, particularly preeclampsia, and associated adverse outcomes.

EVIDENCE

A comprehensive literature review was updated to December 2020, following the same methods as for previous Society of Obstetricians and Gynaecologists of Canada (SOGC) HDP guidelines, and references were restricted to English or French. To support recommendations for therapies, we prioritized randomized controlled trials and systematic reviews (if available), and evaluated substantive clinical outcomes for mothers and babies.

VALIDATION METHODS

The authors agreed on the content and recommendations through consensus and responded to peer review by the SOGC Maternal Fetal Medicine Committee. The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, along with the option of designating a recommendation as a "good practice point." See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and conditional [weak] recommendations).The Board of the SOGC approved the final draft for publication.

INTENDED USERS

All health care providers (obstetricians, family doctors, midwives, nurses, and anesthesiologists) who provide care to women before, during, or after pregnancy.

RECOMMENDATIONS

Fetal inflammatory response at the fetomaternal interface: A requirement for labor at term and preterm

Human parturition at term and preterm is an inflammatory process synchronously executed by both fetomaternal tissues to transition them from a quiescent state t an active state of labor to ensure delivery. The initiators of the inflammatory signaling mechanism can be both maternal and fetal. The placental (fetal)-maternal immune and endocrine mediated homeostatic imbalances and inflammation are well reported. However, the fetal inflammatory response (FIR) theories initiated by the fetal membranes (amniochorion) at the choriodecidual interface are not well established. Although immune cell migration, activation, and production of proparturition cytokines to the fetal membranes are reported, cellular level events that can generate a unique set of inflammation are not well discussed. This review discusses derangements to fetal membrane cells (physiologically and pathologically at term and preterm, respectively) in response to both endogenous and exogenous factors to generate inflammatory signals. In addition, the mechanisms of inflammatory signal propagation (fetal signaling of parturition) and how these signals cause immune imbalances at the choriodecidual interface are discussed. In addition to maternal inflammation, this review projects FIR as an additional mediator of inflammatory overload required to promote parturition.

Association of Maternal Serum Uric Acid and Cystatin C Levels in Late Pregnancy with Adverse Birth Outcomes: An Observational Cohort Study in China

Objective

To investigate the associations between serum uric acid (UA) and cystatin C (CysC) levels in late pregnancy with major unfavorable birth outcomes.

Methods

We retrospectively analyzed the maternal UA and CysC levels during late pregnancy and their relationship with unfavorable birth outcomes in a Chinese population (n = 11,580).

Results

Women with the highest quartile of UA had higher risks of low birth weight (LBW) and small for gestational age (SGA) babies and a lower risk of preterm birth (PTB) compared to women with the lowest quartile [for LBW, adjusted-odds ratio (OR) = 2.63, 95% CI: 1.76, 3.95; for SGA, adjusted-OR = 2.11, 95% CI: 1.73, 2.57; for PTB, adjusted-OR = 0.55, 95% CI: 0.45, 0.69; all P for trend <0.001]. Compared to women in the lowest quartile of CysC, higher risks of macrosomia and large for gestational age (LGA) and lower risks of PTB and SGA were observed for those in the highest quartile (for macrosomia, adjusted-OR = 2.01, 95% CI: 1.60, 2.51; for LGA, adjusted-OR = 1.97, 95% CI: 1.67, 2.32; for PTB, adjusted-OR = 0.32, 95% CI: 0.26, 0.41; all P for trend <0.001; for SGA, adjusted-OR = 0.78, 95% CI: 0.64, 0.96; P for trend <0.05).

Conclusion

This study reports the associations of maternal UA and CysC with adverse birth outcomes, and suggests that routine determination of maternal UA and CysC in late pregnancy is beneficial for assessing the risks of these 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.

Per- and polyfluoroalkyl substance (PFAS) exposure, maternal metabolomic perturbation, and fetal growth in African American women: A meet-in-the-middle approach

BACKGROUND

Prenatal exposures to per- and polyfluoroalkyl substances (PFAS) have been linked to reduced fetal growth. However, the detailed molecular mechanisms remain largely unknown. This study aims to investigate biological pathways and intermediate biomarkers underlying the association between serum PFAS and fetal growth using high-resolution metabolomics in a cohort of pregnant African American women in the Atlanta area, Georgia.

METHODS

Serum perfluorohexane sulfonic acid (PFHxS), perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA) measurements and untargeted serum metabolomics profiling were conducted in 313 pregnant African American women at 8-14 weeks gestation. Multiple linear regression models were applied to assess the associations of PFAS with birth weight and small-for-gestational age (SGA) birth. A high-resolution metabolomics workflow including metabolome-wide association study, pathway enrichment analysis, and chemical annotation and confirmation with a meet-in-the-middle approach was performed to characterize the biological pathways and intermediate biomarkers of the PFAS-fetal growth relationship.

RESULTS

Each log2-unit increase in serum PFNA concentration was significantly associated with higher odds of SGA birth (OR = 1.32, 95% CI 1.07, 1.63); similar but borderline significant associations were found in PFOA (OR = 1.20, 95% CI 0.94, 1.49) with SGA. Among 25,516 metabolic features extracted from the serum samples, we successfully annotated and confirmed 10 overlapping metabolites associated with both PFAS and fetal growth endpoints, including glycine, taurine, uric acid, ferulic acid, 2-hexyl-3-phenyl-2-propenal, unsaturated fatty acid C18:1, androgenic hormone conjugate, parent bile acid, and bile acid-glycine conjugate. Also, we identified 21 overlapping metabolic pathways from pathway enrichment analyses. These overlapping metabolites and pathways were closely related to amino acid, lipid and fatty acid, bile acid, and androgenic hormone metabolism perturbations.

CONCLUSION

In this cohort of pregnant African American women, higher serum concentrations of PFOA and PFNA were associated with reduced fetal growth. Perturbations of biological pathways involved in amino acid, lipid and fatty acid, bile acid, and androgenic hormone metabolism were associated with PFAS exposures and reduced fetal growth, and uric acid was shown to be a potential intermediate biomarker. Our results provide opportunities for future studies to develop early detection and intervention for PFAS-induced fetal growth restriction.

Technologies for Prediction of Preeclampsia

The aim of the study was to develop technologies for predicting the development of preeclampsia (PE) based on biomedical and molecular-genetic predictors and the calculation of individual risks for this pregnancy complication.

Gestational Hypertension and Preeclampsia: An Overview of National and International Guidelines

Importance

Gestational hypertension and preeclampsia are leading causes of maternal and perinatal morbidity and mortality worldwide. Τhe lack of effective screening and management policies appears to be one of the main reasons.

Objective

The aim of this study was to review and compare recommendations from published guidelines on these common pregnancy complications.

Evidence Acquisition

A descriptive review of guidelines from the National Institute for Health and Care Excellence, the Society of Obstetric Medicine of Australia and New Zealand, the International Society of Hypertension, the International Society for the Study of Hypertension in Pregnancy, the European Society of Cardiology, the International Federation of Gynecology and Obstetrics, the Society of Obstetricians and Gynaecologists of Canada, the American College of Obstetricians and Gynecologists, the International Society of Ultrasound in Obstetrics and Gynecology, the World Health Organization, and the US Preventive Services Task Force on gestational hypertension and preeclampsia was carried out.

Results

There is an overall agreement that, in case of suspected preeclampsia or new-onset hypertension, blood and urine tests should be carried out, including dipstick test for proteinuria, whereas placental growth factor-based testing is only recommended by the National Institute for Health and Care Excellence and the European Society of Cardiology. In addition, there is a consensus on the recommendations for the medical treatment of severe and nonsevere hypertension, the management of preeclampsia, the appropriate timing of delivery, the optimal method of anesthesia and the mode of delivery, the administration of antenatal corticosteroids and the use of magnesium sulfate for the treatment of eclamptic seizures, the prevention of eclampsia in cases of severe preeclampsia, and the neuroprotection of preterm neonates. The reviewed guidelines also state that, based on maternal risk factors, pregnant women identified to be at high risk for preeclampsia should receive low-dose aspirin starting ideally in the first trimester until labor or 36 to 37 weeks of gestation, although the recommended dose varies between 75 and 162 mg/d. Moreover, most guidelines recommend calcium supplementation for the prevention of preeclampsia and discourage the use of other agents. However, controversy exists regarding the definition and the optimal screening method for preeclampsia, the need for treating mild hypertension, the blood pressure treatment targets, and the postnatal blood pressure monitoring.

Conclusions

The development and implementation of consistent international protocols will allow clinicians to adopt effective universal screening, as well as preventive and management strategies with the intention of improving maternal and neonatal outcomes.

Serum Uric Acid Level as a Predictive Biomarker of Gestational Hypertension Severity; A Prospective Observational Case-Control Study

BACKGROUND

Pre-eclampsia poses a significant potential risk of hypertensive disorders during pregnancy, a leading cause of maternal deaths. Hyperuricemia is associated with adverse effects on endothelial function, normal cellular metabolism, and platelet aggregation and adhesion. This study was designed to compare serum urate levels in normotensive pregnant women to those with pregnancy-induced hypertension, and to evaluate its value as a potential predictive marker of hypertension severity during pregnancy.

METHODS

A prospective, observational, case-control study conducted on 100 pregnant women in their third trimester. Pregnant women were classified into two groups (n=50) according to arterial blood pressure measurements: group I had normal blood pressure, and group II had a blood pressure of ≥ 140/90, which was further subdivided according to hypertension severity into IIa (pregnancy- induced hypertension, IIb (mild pre-eclampsia), and IIc (severe pre-eclampsia). Blood samples were obtained on admission. Serum urate, high sensitive C-reactive protein, and interleukin-1β levels, and lipid profile were compared among the groups.

RESULTS

A significant increase in the mean values of serum urate, C-reactive protein, and interleukin- 1β levels was detected in gestational hypertensives. In addition, there was a positive correlation between serum urate levels and C-reactive protein and interleukin-1β, as well as between serum urate levels and hypertension severity.

CONCLUSION

Hyperuricemia and increased C-reactive protein and interleukin-1β serum levels correlate with the severity of pregnancy-induced hypertension, and these biomarkers may play a role in the pathogenesis of pre-eclampsia. Serum urate measurement is sensitive, reliable markers that correlate well with the severity of hypertension in pregnant females with pre-eclampsia.

Maternal serum uric acid: a reliable prognostic indicator of foetal outcome among pre-eclamptic patients in a low resource setting

BACKGROUND

Pre-eclampsia is a major cause of maternal and fetal morbidity and mortality in both developed and developing countries. Hyperuricemia is often associated with pre-eclampsia and when this occurs, fetal outcome may become worse. We evaluated the role of maternal serum uric acid as a prognostic indicator of fetal outcome in pre-eclamptic mothers.

METHODS

A prospective case-control study in which 55 eligible pre-eclamptic patients at term were matched in maternal age and gestational age with 55 consecutive normotensive pregnant women. Venous blood samples were obtained and analyzed for serum uric acid. Following delivery, the fetal outcomes in the pre-eclamptic group and controls were determined. Data analysis was carried out using SPSS (version 21) and the level of statistical significance was set at p-value <.05.

RESULTS

The mean serum uric acid levels of the pre-eclamptic subjects was significantly higher compared to their normotensive counterparts (12.7 ± 7.8 vs. 4.9 ± 1.2 mg/dL, p = .000). Babies with low birth weight, poor Apgar scores (at 1st and 5th minute of life) and those who required neonatal unit admission occurred more significantly among the pre-eclamptic women when compared with the controls (p = .000). However, the live birth rate of the case and control groups was comparable (94.5% vs. 100%, p = .079), Binary logistic regression analysis revealed a positive association between hyperuricemia and pre-eclampsia (OR = 18.8; 95% CI = 1.22-289.35, p = .035). Pre-eclamptic mothers with hyperuricemia had 4.41 odds of delivering babies with low birth weight when compared with pre-eclamptics without hyperuricemia (OR = 4.41; 95% CI = 0.76-25.5, p = .097); but Apgar scores and need for neonatal admission showed no association with maternal serum uric acid levels.

CONCLUSION

This study therefore suggests that hyperuricemia is a strong prognostic indicator of LBW babies among women with pre-eclampsia.

Association between Serum Uric Acid Levels and Perinatal Outcome in Women with Preeclampsia

Objectives

To compare serum uric acid levels with disease severity and perinatal outcome among preeclamptic and normal pregnant women.

Materials and Methods

This was a case-control study carried out in Federal Medical Centre, Umuahia, Nigeria. Consenting pregnant women were consecutively recruited into two groups comprising pregnant women diagnosed with preeclampsia and normotensive nonproteinuric pregnant women. Exclusion criteria included pregnant women who were current smokers, took alcohol, and diagnosed with multiple gestation, diabetes mellitus, or renal failure. Associations between categorical variables such as preeclampsia severity and perinatal outcomes were done using logistic regression while means of continuous variables such as serum uric acid were compared using Student's t-test. Data were presented using odds ratios (ORs) with 95% confidence intervals (95% CI) and a statistical significance level set at P value ˂ 0.05. Data analysis was done using Statistical Package for Social Sciences version 22.

Results

One hundred and two participants were finally analysed. Fifty-one participants were recruited in each arm. Women with preeclampsia had significantly high serum uric acid level versus controls (6.08 ± 0.49 mg/dL vs. 5.20 ± 0.19; P < 0.001). Women with elevated serum uric acid levels (˃6 mg/dL) were found to be 4 times more likely to have severe preeclampsia (P=0.022, OR = 4.00, 95% CI = 1.225–13.056), 66 times more likely to have APGAR score ˂7 in the first minute (P < 0.001, OR = 66.00, 95% CI = 6.991–623.128), and 3 times more likely to have lower birth weight (P=0.038, OR = 3.400, 95% CI = 1.073–10.775) than those with normal serum uric acid levels.

Conclusions

The mean serum uric acid level in a preeclamptic is higher than that of normal pregnant control, and higher levels are associated with severity of the disease and significantly associated with poorer perinatal outcome.

Foetal and maternal outcomes in hyperuricaemia pre-eclampsia patients in Hospital Universiti Sains Malaysia

Preeclampsia patients have frequently been found to experience hyperuricaemia and this may result in poor outcomes compared to those with normal uric acid levels. This study aimed to determine the relationship of hyperuricaemia in pre-eclampsia patients with foetal and maternal outcomes. This prospective cohort study involved 79 patients in a tertiary centre from year 2016 to 2018. Blood samples were taken antenatally and at the 6th week, post-delivery for renal function including serum uric acid level. Our findings indicate that there was a higher incidence of poor maternal and foetal outcomes in the hyperuricaemia group than the normal uric acid group. Serum uric acid has been shown to be a significant predictor for low birth weight and premature delivery in preeclampsia patients. It was also found that there was a significant negative correlation between uric acid level and antenatal creatinine clearance (r_s = -0.338, p = .002). The assessment of the serum uric acid level seems to be important to ensure better outcomes in patients with preeclampsia.Impact statementWhat is already known on this subject? Preeclampsia is a serious pregnancy-related complication and remains as one of the most important cause of maternal and foetal morbidity and mortality, affecting 2-8% in all pregnancy. Many studies have established the association between hyperuricaemia and preeclampsia. Besides, numerous studies have found that hyperuricaemia contributed to adverse maternal and foetal outcomes.What the results of this study add? There was a significant increase in adverse foetal and maternal outcomes in the hyperuricaemia group compared to the normal uric acid group. This study revealed that serum uric acid remains a significant predictor for low birth weight and premature delivery in preeclampsia patients.What the implications are of these findings for clinical practice and/or further research? Hyperuricaemia does not merely become an indicator for the severity of disease in preeclampsia patients but also indicates adverse foetal outcomes. Large population-based studies are required to establish the absolute maternal and foetal outcomes in patients with hyperuricaemia. Besides, further studies are recommended on long-term implication of hyperuricaemia which is not limited to only during antenatal period.

Evaluation of obstructive sleep apnea prevalence in mothers of infants with low birth weight and its relationship with serum uric acid levels as a hypoxia marker

OBJECTIVE

Serum uric acid level, which is an oxidative stress marker, may increase in some conditions that lay the ground for the hypoxia. However, recent literature lacks studies with large series on this subject. We aimed to examine the incidence of OSAS in mothers who delivered a low birth weight baby and its association with serum uric acid levels as a hypoxia marker.

METHODS

We enrolled 143 pregnant women, 44 of whom delivered a low birth weight (LBW) baby. We made a face-to-face interview in which we asked the questions in the patient follow-up form, comprising three sections. The form included questions regarding the sociodemographic features and obstetric history of the participant women, besides the Berlin Questionnaire and the Epworth Sleepiness Scale. We recorded the blood test parameters that are obtained from patient records in the last section.

RESULTS

Mean uric acid (UA) levels of mothers with a LBW baby (n = 44, birth weight below 2500 g) were 4.51 ± 1.23 mg/dL (min-max = 2.7-8.0) while the UA levels in mothers of normal weighted (NBW) babies (n = 99, birth weight is 2500 g or above) were 4.08 ± 0.75 (min-max = 2.6-6.1 mg/dL). The UA levels of mothers who delivered LBW infants were significantly higher compared with the mothers of NBW babies (p = .010).

CONCLUSION

Uric acid levels can be used as a prognostic parameter for the closer monitoring of pregnant women who have been diagnosed with small-for-gestational-age babies during pregnancy.

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.

Uric acid levels in gestational hypertensive women predict preeclampsia and outcome of small-for-gestational-age infants

OBJECTIVE

This study aims to ascertain whether serum uric acid is a suitable predictor of preeclampsia and/or the delivery of small-for-gestational-age infants for women with gestational hypertension.

METHODS

364 singleton pregnant women with initial presentation of gestational hypertension were recruited and followed up until 6 weeks after delivery. Uric acid z score and binary logistic regression analysis were applied to establish the relationship between serum uric acid and the chance of progression to preeclampsia and giving birth to a small-for-gestational-age infant. Furthermore, receiver operating characteristic (ROC) analysis was used to evaluate the prediction value of serum uric acid.

RESULTS

Uric acid z score and binary logistic regression analysis indicated that elevated serum uric acid increased the chances of gestational hypertension progression to preeclampsia and subsequent delivery of small-for-gestational-age infants. ROC analysis showed that serum uric acid at a cutoff value of 303μmol l-1, moderately predict the development of preeclampsia and the delivery of small-for-gestational age infants. The prediction values of preeclampsia were 90.7% sensitivity, 69.4% specificity, 97.7% negative predictor values and 34.0% positive predictor values, comparatively, the prediction value for small-for-gestational age infant was low. The ROC curve improved with 95.8% sensitivity, 86.7% specificity, 98.1% NPV, and 74.2% PPV in the Chinese Han women with early onset of gestational hypertension thus the diagnosis of gestational hypertension before 34 weeks.

CONCLUSIONS

Elevated serum uric acid in Chinese Han women with gestational hypertension indicated an increased risk of their progression to preeclampsia and the further delivering of small-for-gestational-age infants.

Is maternal dietary selenium intake related to antioxidant status and the occurrence of pregnancy complications?

Selenium (Se) is a trace element essential for the appropriate course of vital processes in the human body. It is also a constituent of the active center of glutathione peroxidase and other antioxidant compounds which play an important role in red-ox processes. Associations between lower blood selenium concentration and obstetric complications has been reported in many studies. The aim of this study was to determine the dietary selenium intake and serum selenium content in pregnant Polish women and relate this to antioxidant status as whole blood glutathione peroxidase (GPX) activity, serum uric acid (UA) content and serum total antioxidant status (TAS) and pregnancy complications occurrence. Ninety-four pregnant women at a mean age 30.6 ± 5.4 years from the Lower Silesia region of Poland were recruited to the study, 37% of studied group had pregnancy complications. The mean reported Se intake and serum selenium content for Polish pregnant women was in the first trimester - 53.99 μg/day and 44.36 μg/l, the second trimester - 58.93 μg/day and 43.16 μg/l and the third trimester - 62.89 μg/day and 40.97 μg/l, respectively. Selenium intake below or above recommended value hadn't significant effect on GPX activity, TAS and UA levels. There were no statistical differences in selenium intake, serum selenium content, GPX activity and TAS and UA level between physiological and complicated pregnancy, but a positive correlation between Se intake and serum selenium content was observed during all period of gestation as well as in the second trimester of pregnancy between Se intake and GPX activity in group with physiological pregnancy where selenium intake was below the recommended level. Selenium intake above the recommended level was positively correlated also with serum UA level in first and second trimester of pregnancy. Despite weak, positive correlations in the first two trimesters of pregnancy between selenium supply and GPX activity and UA concentration we concluded that selenium intake does not significantly affect during pregnancy, both: markers of the antioxidant status of pregnant women and the occurrence of pregnancy complications.

Biochemical tests of placental function versus ultrasound assessment of fetal size for stillbirth and small-for-gestational-age infants

BACKGROUND

Stillbirth affects 2.6 million pregnancies worldwide each year. Whilst the majority of cases occur in low- and middle-income countries, stillbirth remains an important clinical issue for high-income countries (HICs) - with both the UK and the USA reporting rates above the mean for HICs. In HICs, the most frequently reported association with stillbirth is placental dysfunction. Placental dysfunction may be evident clinically as fetal growth restriction (FGR) and small-for-dates infants. It can be caused by placental abruption or hypertensive disorders of pregnancy and many other disorders and factorsPlacental abnormalities are noted in 11% to 65% of stillbirths. Identification of FGA is difficult in utero. Small-for-gestational age (SGA), as assessed after birth, is the most commonly used surrogate measure for this outcome. The degree of SGA is associated with the likelihood of FGR; 30% of infants with a birthweight < 10th centile are thought to be FGR, while 70% of infants with a birthweight < 3rd centile are thought to be FGR. Critically, SGA is the most significant antenatal risk factor for a stillborn infant. Correct identification of SGA infants is associated with a reduction in the perinatal mortality rate. However, currently used tests, such as measurement of symphysis-fundal height, have a low reported sensitivity and specificity for the identification of SGA infants.

OBJECTIVES

The primary objective was to assess and compare the diagnostic accuracy of ultrasound assessment of fetal growth by estimated fetal weight (EFW) and placental biomarkers alone and in any combination used after 24 weeks of pregnancy in the identification of placental dysfunction as evidenced by either stillbirth, or birth of a SGA infant. Secondary objectives were to investigate the effect of clinical and methodological factors on test performance.

SEARCH METHODS

We developed full search strategies with no language or date restrictions. The following sources were searched: MEDLINE, MEDLINE In Process and Embase via Ovid, Cochrane (Wiley) CENTRAL, Science Citation Index (Web of Science), CINAHL (EBSCO) with search strategies adapted for each database as required; ISRCTN Registry, UK Clinical Trials Gateway, WHO International Clinical Trials Portal and ClinicalTrials.gov for ongoing studies; specialist abstract and conference proceeding resources (British Library's ZETOC and Web of Science Conference Proceedings Citation Index). Search last conducted in Ocober 2016.

SELECTION CRITERIA

We included studies of pregnant women of any age with a gestation of at least 24 weeks if relevant outcomes of pregnancy (live birth/stillbirth; SGA infant) were assessed. Studies were included irrespective of whether pregnant women were deemed to be low or high risk for complications or were of mixed populations (low and high risk). Pregnancies complicated by fetal abnormalities and multi-fetal pregnancies were excluded as they have a higher risk of stillbirth from non-placental causes. With regard to biochemical tests, we included assays performed using any technique and at any threshold used to determine test positivity.

DATA COLLECTION AND ANALYSIS

We extracted the numbers of true positive, false positive, false negative, and true negative test results from each study. We assessed risk of bias and applicability using the QUADAS-2 tool. Meta-analyses were performed using the hierarchical summary ROC model to estimate and compare test accuracy.

MAIN RESULTS

We included 91 studies that evaluated seven tests - blood tests for human placental lactogen (hPL), oestriol, placental growth factor (PlGF) and uric acid, ultrasound EFW and placental grading and urinary oestriol - in a total of 175,426 pregnant women, in which 15,471 pregnancies ended in the birth of a small baby and 740 pregnancies which ended in stillbirth. The quality of included studies was variable with most domains at low risk of bias although 59% of studies were deemed to be of unclear risk of bias for the reference standard domain. Fifty-three per cent of studies were of high concern for applicability due to inclusion of only high- or low-risk women.Using all available data for SGA (86 studies; 159,490 pregnancies involving 15,471 SGA infants), there was evidence of a difference in accuracy (P < 0.0001) between the seven tests for detecting pregnancies that are SGA at birth. Ultrasound EFW was the most accurate test for detecting SGA at birth with a diagnostic odds ratio (DOR) of 21.3 (95% CI 13.1 to 34.6); hPL was the most accurate biochemical test with a DOR of 4.78 (95% CI 3.21 to 7.13). In a hypothetical cohort of 1000 pregnant women, at the median specificity of 0.88 and median prevalence of 19%, EFW, hPL, oestriol, urinary oestriol, uric acid, PlGF and placental grading will miss 50 (95% CI 32 to 68), 116 (97 to 133), 124 (108 to 137), 127 (95 to 152), 139 (118 to 154), 144 (118 to 161), and 144 (122 to 161) SGA infants, respectively. For the detection of pregnancies ending in stillbirth (21 studies; 100,687 pregnancies involving 740 stillbirths), in an indirect comparison of the four biochemical tests, PlGF was the most accurate test with a DOR of 49.2 (95% CI 12.7 to 191). In a hypothetical cohort of 1000 pregnant women, at the median specificity of 0.78 and median prevalence of 1.7%, PlGF, hPL, urinary oestriol and uric acid will miss 2 (95% CI 0 to 4), 4 (2 to 8), 6 (6 to 7) and 8 (3 to 13) stillbirths, respectively. No studies assessed the accuracy of ultrasound EFW for detection of pregnancy ending in stillbirth.

AUTHORS' CONCLUSIONS

Biochemical markers of placental dysfunction used alone have insufficient accuracy to identify pregnancies ending in SGA or stillbirth. Studies combining U and placental biomarkers are needed to determine whether this approach improves diagnostic accuracy over the use of ultrasound estimation of fetal size or biochemical markers of placental dysfunction used alone. Many of the studies included in this review were carried out between 1974 and 2016. Studies of placental substances were mostly carried out before 1991 and after 2013; earlier studies may not reflect developments in test technology.

Predictive value of serum uric acid levels for adverse perinatal outcomes in preeclampsia

Preeclampsia is a multisystem disorder associated with pregnancy and is a common cause of perinatal morbidity. The aim of this study was to determine whether elevated serum uric acid levels, alone or in combination with other laboratory factors could predict preeclampsia in women with adverse perinatal outcomes.We conducted a prospective observational study of women who were admitted to Soonchunhyang University Cheonan Hospital from January 2016 to December 2016. Demographic, clinical and laboratory data were collected for each pregnancy at the time of delivery. Women were grouped according to status (preeclampsia or normotensive), and a logistic regression analysis was used to determine the relationship between serum uric acid levels and adverse outcomes.The mean age of the study participants was 31.3 ± 5.0 years. In patients with preeclampsia, serum uric acid level was associated with the severity of preeclampsia, including blood pressure (R = 0.321, P = .014), serum creatinine levels (R = 0.505, P < .001), and proteinuria (P = .014), as well as adverse fetal outcomes, including preterm labor (P = .027) and low birth weight delivery (P = .001). The optimal maternal serum uric acid threshold that predicted low birth weight at delivery was 6.35 mg/dL (sensitivity, 0.58; specificity, 0.95). The multivariable logistic regression model that was used to predict low birth weight at delivery displayed an area under the receiver-operating characteristic curve of 0.902 (95% confidence interval, 0.817-0.986).In women with preeclampsia, maternal serum uric acid level is an important parameter for predicting low birth weight. Additionally, the combination of uric acid, hemoglobin, and bilirubin levels appear to be optimal for predicting low birth weight in women with preeclampsia.

Maternal Serum Uric Acid as a Predictor of Severity of Hypertensive Disorders of Pregnancy: A Prospective Cohort Study

Objective: To assess the relationship between maternal serum uric acid and severity of Hypertensive disorders of pregnancy in a rural tertiary care centre.

Materials and Methods: Present study was conducted in Obstetrics and Gynaecology department of rural tertiary care cen-tre of Northern India over seven months (October 2016-May 2017) on 110 women admitted with a Hypertensive disorder of pregnancy (Gestational hypertension, Pre-eclampsia, Eclampsia) at ≥34 weeks gestation. Maternal serum uric acid levels were compared in three groups in relation to disease severity, mode of delivery, maternal outcome.

Results: Of total 110 women with a Hypertensive disorder of pregnancy; 35 (31.81%) had Gestational Hypertension, 49 (44.54%) preeclampsia and 26 (23.63%) had eclampsia. Mean±SD values for serum uric acid were 5.47±1.93 mg/dl in women with Gestational Hypertension; 6.72±2.15 mg/dl in Pre-eclampsia and 8.71±2.97 mg/dl in the eclamptic group. Of 110 women 34(97.14%) with gestational hypertension, 27(55.10%) with pre-eclampsia and one (3.85%) with eclampsia re-mained stable in post-partum period, 17 (34.69%) women with severe pre-eclampsia and 15 (57.69%) with eclampsia re-quired intensive care in postpartum period and one (2.86%) women with gestational hypertension, five (10.20%) with pre-eclmapsia and ten (38.46%) with eclampsia required ventilator support and high dependency unit care. Of these 16 women with the severe disease, ten succumbed to death. Also, in women with serum uric acid,>6mg/dl, most common mode of de-livery was a lower segment cesarean section (50.90%).

Conclusion: Significant correlation was observed between maternal serum uric acid, disease severity and maternal outcome.

Maternal serum uric acid concentration and pregnancy outcomes in women with pre-eclampsia/eclampsia

Objectives

To determine the relationship between maternal serum uric acid levels and fetal/neonatal complications in women with pre‐eclampsia/eclampsia, and to establish a predictive threshold value.

Methods

A diagnostic test and historical cohort study conducted by prospective cross‐sectional data collection on pregnant women with pre‐eclampsia/eclampsia at Hue University Hospital, Vietnam, between March 2015 and July 2017. Pre‐eclampsia was diagnosed based on ACOG criteria. Serum uric acid levels were measured by enzymatic colorimetric testing using a Cobas c 501 analyzer (Roche Diagnostics, Mannheim, Germany). Fetal complications included intrauterine growth restriction, preterm delivery, fetal death, and neonatal death.

Results

There were 205 women enrolled. Serum uric acid at a cutoff of 393 μmol/L is a good predictor of fetal/neonatal complications (AUC 0.752), with 64.4% sensitivity and 79.5% specificity. High uric acid level (≥393 μmol/L) resulted in increased risk of preterm birth (OR 6.367, 95% CI 3.009–13.084), low Apgar scores (OR 5.514, 95% CI 1.877–16.198), intrauterine growth restriction (OR 7.188, 95% CI 3.592–14.382), and neonatal death (OR 7.818, 95% CI 1.614–37.867). There was no relationship between uric acid level and fetal death (OR 1.803, 95% CI 0.355–9.168).

Conclusions

Maternal serum uric acid concentration is a good predictor of fetal/neonatal outcomes in women with pre‐eclampsia/eclampsia.

Maternal serum uric acid concentration is a good predictor of fetal/neonatal outcomes in pregnant women with pre‐eclampsia/eclampsia.

Association between the prevalence of hyperuricemia and reproductive hormones in polycystic ovary syndrome

BACKGROUND

The prevalecne of hyperuricemia in polycystic ovary syndrome (PCOS) is still uncertain. We aimed to investigate the prevalence of hyperuricemia in PCOS and to determine the influence of reproductive hormones on uric acid concentration.

METHODS

This retrospective cross-sectional study was performed at a large reproductive medicine center. Between March 2007 and October 2016, a total of 1,183 women with PCOS and 10,772 women without PCOS were included. PCOS was diagnosed according to the Rotterdam criteria. Anthropometric parameters, blood pressure, uric acid, reproductive hormones, glucose and lipids were measured in all subjects.

RESULTS

The serum uric acid (SUA) level was higher in women with PCOS than in women without PCOS. The prevalence of hyperuricemia in women with PCOS (25.48%) was significantly higher than that in women without PCOS (8.74%). Analysis stratified for age and body mass index (BMI) showed that both the SUA level and the prevalence of hyperuricemia were higher in women with PCOS of different age and BMI groups than in women without PCOS. After adjusting for age, BMI and estimated glomerular filtration rate (eGFR), logistic regression analysis revealed that the luteinizing/follicle-stimulating hormone (LH/FSH) ratio (odds ratio (OR) = 1.20, 95% CI = 1.01-1.43) and testosterone level (OR = 1.56, 95% CI = 1.27-1.90) were positively associated with the prevalence of hyperuricemia in females with PCOS.

CONCLUSIONS

The serum uric acid (SUA) level and the prevalence of hyperuricemia markedly increased in women with PCOS. The testosterone level was positively associated with the SUA level and the prevalence of hyperuricemia in females with PCOS.

Preeclampsia and the challenge of early prediction: reality or utopia? State of art and critical review of literature

Purpose: The challenge to obtain improved predictive tools, able to identify women destined to develop preeclampsia (PE), is raising the interest of researchers for the attractive chance to allow for timely initiation of prophylactic therapy, appropriate antenatal surveillance, and better-targeted research into preventive interventions. We aimed to gather all the evidence reported up to now in scientific literature relating to all prediction tests for PE.Materials and methods: We searched articles on conventional literature platforms from January 1952 to August 2016, using the terms "preeclampsia," "gestational preeclampsia," and "gestational hypertensive disorders" combined with "predictive test" and "risk assessment." Abstracts/titles identified by the search were screened by three investigators.Results: The search identified 203 citations, of which 154 potentially relevant after the initial evaluation. Among these studies, 20 full articles were excluded, therefore, 134 primary studies met the criteria for inclusion and were analyzed.Conclusions: Current evidence suggests that a combination of several features may provide the best predictive accuracy for the identification of PE. Large-scale, multicenter, multiethnic, prospective trials are required to propose an ideal combination of markers for routine screening.

Candidate Gene, Genome-Wide Association and Bioinformatic Studies in Pre-eclampsia: a Review

PURPOSE OF REVIEW

Regardless of the familial linkage reported in pre-eclampsia development, understanding the polymorphic genes associated with pre-eclampsia remains limited. Hence, this review aims to outline the main genetic factors that have been investigated in respect to pre-eclampsia development.

RECENT FINDINGS

It is apparent that different genes show significance in varying populations. Notably, it is reported that apolipoprotein-1 gene polymorphisms are associated with pre-eclampsia development in an African-American population, which may be worthwhile to investigate in a Black South African cohort. Despite the research attention that is focused on this surreptitious syndrome, a definitive cause eludes scientists and physicians, alike. Genetic studies can fulfil a dual purpose of suggesting novel hypotheses through genome-wide screening and testing these hypotheses via candidate gene studies. However, publications to date have only presented inconsistent and conflicting results regarding candidate gene analysis.

Association of maternal uric acid and cystatin C serum concentrations with maternal and neonatal cardiovascular risk markers and neonatal body composition: The Ulm SPATZ Health Study

Purpose

In utero exposure to cardiometabolic risk factors may determine health related outcomes at birth and in later life. The aim of this analysis was to describe the relationship of maternal serum uric acid (SUA) and cystatin C with maternal and neonatal cardiometabolic risk markers and with birth weight and risk of small-for-gestational age (SGA) as well as large-for gestational age (LGA).

Material and methods

In the Ulm SPATZ Health Study, 934 singleton newborns and their mothers were recruited during their hospital stay in the University Medical Center Ulm between 04/2012 and 05/2013 (overall response 49%). The association between SUA and cystatin C (both in quartiles and as continuous measures) with risk for SGA as well as with LGA was quantified by means of multivariable logistic regression.

Results

Overall, n = 885 mother-newborn pairs were included in the final analysis. Most of the mothers were of German nationality (85%) and were between 26 and 35 years of age at delivery (69%). Maternal SUA was associated with maternal age, body mass index, alcohol consumption and history of hypertension as well as with many other maternal and neonate cardiovascular risk markers. Cystatin C was associated with parity. No clear association of SUA with SGA and LGA was observed in fully adjusted models. However, cystatin C was negatively associated with SGA with an odds ratio (OR) of 0.35 (95% CI: 0.16–0.77; p for trend 0.04) comparing the top quartile vs. the bottom quartile and was positively associated with LGA with an OR of 5.92 (95% CI: 2.27–15.44; p for trend <0.0001) after adjustment for covariates.

Conclusions

We found a positive association of cystatin C with birth weight and a clearly increased risk for LGA with maternal increased cystatin C values in a population with fairly normal renal function.

The association of hyperuricemia and immediate postpartum hypertension in women without a diagnosis of chronic hypertension

Our objective was to determine if elevated uric acid (UA) is associated with postpartum hypertension (PP HTN) in women without chronic hypertension. This is a secondary analysis of a randomized trial. We compared those with elevated UA to those with normal UA. Logistic regression was conducted to determine the association of elevated UA with PP HTN. Five hundred and fifty-six women met criteria. An UA level ≥ 5.2 mg/dL was associated with immediate PP HTN (adjusted odds ratio 2.44, 95% CI 1.63-3.64). The association was stronger among overweight and obese women. We conclude that hyperuricemia is associated with PP HTN, especially among obese women.

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

PURPOSE OF REVIEW

Because of the significant discrepancies on this topic, this review will focus on the role of uric acid in PE, uric acid as a predictor of preeclampsia and fetal growth retardation. We considered eligible review and original articles relevant to the research question.

RECENT FINDINGS

Hypertensive disorders of pregnancy such as preeclampsia (PE) are a major cause of both maternal and fetal morbidity and mortality worldwide. Uric acid has been reported as a key factor contributing to the pathogenesis of PE. Some studies have indicated that serum uric acid levels increase with the severity of PE, while several studies have shown contradictory results. Some studies suggested high uric acid levels lead to PE, while others state that PE causes an increase in uric acid levels. Despite the strong association of uric acid in the pathogenesis of preeclampsia, current data is still contradictory hence genetic and high-end laboratory investigations may clarify this enigma.

Maternal serum uric acid levels in pregnancy and fetal growth

Objective: Studies of maternal serum uric acid (UA) in pregnancy focus primarily on high levels of UA, however, both low and high UA levels can be markers of oxidative stress, a biological state potentially linked to fetal growth. We therefore aimed to test whether low and high maternal serum UA levels during pregnancy are associated with atypical fetal growth (unusually small or large) measured as birthweight (BW) for gestational age.Methods: The Pregnancy Outcomes and Community Health Study enrolled 3019 pregnant women between their 16th-27th week of pregnancy from 52 clinics in five Michigan communities (1998-2004). Maternal UA levels were measured in blood collected at enrollment among a subcohort of 1291 participants. Infant BW and gestational age were used to calculate gestational age-specific BW Z-score. Infants were grouped as small (SGA = BW < 10th percentile), appropriate (AGA = BW 10th-90th percentile), or large (LGA) = BW > 90th percentile) for their gestational age. Analyses considered multiple potential confounders. Linear spline or multiple linear regression models were applied to evaluate the relationship between maternal UA levels and BW Z-score overall and within SGA, AGA, and LGA groups. Model robustness was tested through bootstrap, sensitivity analysis, and cross-validation techniques.Results: The relation between maternal UA levels and BW Z-score varied by infant group. Among SGA infants, the relation was nonlinear (J-shape): both extremes of UA had lower BW Z-score with a breakpoint of 0.267 mmol/L UA (adjusted regression coefficient β = 2.32, p = .01 for lower UA; adjusted β = -37.38, p < .01 for higher UA). Among AGA infants, there was no significant association, and among LGA infants, the relation was linear (adjusted β = 2.86, p = .03).Conclusions: Future research on maternal UA levels in pregnancy may benefit from considering both very low and high levels, and identifying in utero conditions associated with the two extremes.

An Evaluation of Applicability of Salivary Uric Acid Measurement in Preeclampsia and Normal Pregnancy and Its Correlation with Serum Uric Acid

Purpose

Hypertensive disorders complicate 5-10% of all pregnancies and contribute greatly to maternal morbidity and mortality. There are various biomarkers for detection of preeclampsia. Several studies have reported that positive correlation exists between serum uric acid (UA) levels and adverse maternal and fetal outcome. Significant advances have been made toward validation of salivary biomarkers. We conducted this study to determine levels of salivary UA and its correlation with serum UA normal pregnancy and preeclampsia.

Methods

Present cross-sectional study was conducted in tertiary care teaching hospital in North India. One hundred and fifty participants were divided into control group (50 healthy non-pregnant females), study group I (50 normotensive pregnant females), study group II (50 pregnant females with preeclampsia), and both salivary and serum UA was estimated at the same time.

Results

Saliva UA of study group II (4.86 ± 2.37 mg/dl) was significantly higher (p < 0.001) than that of control group (2.09 ± 1.33 mg/dl) and study group I (3.32 ± 1.77 mg/dl). Serum UA of study group II (6.63 + 2.78 mg/dl) was significantly higher (p < 0.001) than that of control group (2.94 + 1.94 mg/dl) and also study group I (5.18 + 2.31 mg/dl) (p = 0.0006).

Conclusion

UA is present in the saliva of women with preeclampsia and has linear correlation with serum UA. Therefore, salivary UA can be used in place of invasive serum UA to monitor women with preeclampsia. Saliva collection is easy, noninvasive and cost-effective. Salivary UA testing may be useful for monitoring preeclampsia at home-based and hospital setting.

Strontium and its role in preeclampsia

BACKGROUND

Preeclampsia (PE) is considered a specific vascular disease in which endothelial dysfunction may be the crucial factor of its pathogenesis. It has been suggested that strontium (Sr) may play a role in the pathophysiology of PE. Our group established in a previous study the serum levels of Sr in healthy pregnancies, and the main aim of the present study was to evaluate Sr concentrations and oxidative status in preeclamptic women.

METHODS

The study population included women with early-onset PE (E-PE, n = 39), late-onset PE (L-PE, n = 67) and serial samples from a subset of preeclamptic women (PE-ss, n = 20). The control group included women with gestational hypertension (GH, n = 56) and healthy pregnancies (samples collected in the 1st (n = 50), 2nd (n = 51) and 3rd trimesters (n = 53)). Strontium, calcium (Ca), uric acid (UA), placental growth factor (PlGF), soluble fms-like tyrosine kinase 1 (sFlt-1), N-terminal pro-brain natriuretic peptide (NT-proBNP), lipid peroxidation and total antioxidant activity (TAA) were measured in these samples.

RESULTS

Mean Sr levels were significantly higher in PE than in control groups (p ≤ 0.0001). Calcium values were found to be significantly lower in E-PE compared to control groups (p = 0.03). Higher levels of NT-proBNP were found in PE vs. control groups (p < 0.001). sFlt-1/PlGF ratio was higher in E-PE compared to L-PE and GH (p < 0.001). Uric acid levels in PE were significantly higher than in control groups (p < 0.0001). There was a strong positive correlation between UA and Sr in the E-PE serial samples (r = 0.80, p < 0.0001). Lipid peroxidation and lipid peroxidation/TAA ratios were found to be higher in PE, with lower values of TAA.

CONCLUSION

The higher levels of Sr and the alterations of redox status found in preeclamptic women, along with the strong correlation between UA and Sr suggest that this element may be involved in the pathogenesis of PE.

Placental inflammation in pre-eclampsia by Nod-like receptor protein (NLRP)3 inflammasome activation in trophoblasts

Pre-eclampsia is associated with increased levels of cholesterol and uric acid and an inflamed placenta expressing danger-sensing pattern recognition receptors (PRRs). Crystalline cholesterol and uric acid activate the PRR Nod-like receptor protein (NLRP)3 inflammasome to release interleukin (IL)-1β and result in vigorous inflammation. We aimed to characterize crystal-induced NLRP3 activation in placental inflammation and examine its role in pre-eclampsia. We confirmed that serum total cholesterol and uric acid were elevated in pre-eclamptic compared to healthy pregnancies and correlated positively to high sensitivity C-reactive protein (hsCRP) and the pre-eclampsia marker soluble fms-like tyrosine kinase-1 (sFlt-1). The NLRP3 inflammasome pathway components (NLRP3, caspase-1, IL-1β) and priming factors [complement component 5a (C5a) and terminal complement complex (TCC)] were co-expressed by the syncytiotrophoblast layer which covers the placental surface and interacts with maternal blood. The expression of IL-1β and TCC was increased significantly and C5a-positive regions in the syncytiotrophoblast layer appeared more frequent in pre-eclamptic compared to normal pregnancies. In-vitro activation of placental explants and trophoblasts confirmed NLRP3 inflammasome pathway functionality by complement-primed crystal-induced release of IL-1β. This study confirms crystal-induced NLRP3 inflammasome activation located at the syncytiotrophoblast layer as a mechanism of placental inflammation and suggests contribution of enhanced NLRP3 activation to the harmful placental inflammation in pre-eclampsia.

Maternal serum uric acid levels and blood pressure during pregnancy: A community-based cohort study

OBJECTIVE

Studies find both very low and high serum uric acid (UA) levels are related to oxidative stress and to conditions such as cardiovascular diseases and chronic kidney disease in the general population. Pregnancy studies have focused only on high maternal UA. In present study, we tested whether unusually high and low levels of maternal serum UA are associated with increases in blood pressure (BP) during pregnancy.

STUDY DESIGN

The Pregnancy Outcomes and Community Health Study enrolled 3019 pregnant women between their 16th-27th week of pregnancy from 52 clinics in 5 Michigan communities (1998-2004). UA levels were measured in maternal blood collected at enrollment from a sub-cohort of 1223 participants. BP was abstracted from prenatal medical records; these analyses used highest recorded diastolic BP (DBP) and its companion systolic BP (SBP). Mean arterial pressure (MAP) was calculated using the formula of (2 × DBP + SBP)/3. Covariates, including maternal race/ethnicity, age at enrollment, education level, medical insurance status, body mass index before pregnancy, parity, smoking during pregnancy, alcohol use during pregnancy, and gestational week at blood collection, were considered as potential confounding variables. Associations between UA levels and BP were evaluated with linear spline or multiple linear regression models. Models' robustness was examined with bootstrap estimation of variance, sensitivity analysis, and 10-fold cross-validation.

RESULTS

Both DBP and MAP had a J-shaped relationship with maternal UA; the breakpoints (nadirs) were 0.153 and 0.161 mmol/L UA, respectively. For DBP versus UA, adjusted regression coefficient (β) = -95.67 (standard error (SE) = 37.67 and p = 0.01) for the left and adjusted β = 48.95 (SE = 9.56 and p < 0.01) for the right; for MAP versus UA, adjusted β = -58.48 (SE = 31.42 and p = 0.06) for the left and adjusted β = 52.23 (SE = 11.39 and p < 0.01) for the right. Maternal SBP followed a positive linear trend with UA levels (adjusted β = 37.75, SE = 12.93, and p < 0.01). All results were robust.

CONCLUSION

Extreme high and low maternal serum UA levels may be informative in studying maternal blood pressure during pregnancy.

Strontium and oxidative stress in normal pregnancy

BACKGROUND

Pregnancy brings about metabolic and oxidative changes that involve various trace elements and oxidative stress. Strontium (Sr) is a trace element scarcely studied in this context, although it has been suggested that it may play a role in the pathophysiology of preeclampsia. The main aim of this study was to evaluate Sr concentrations and oxidative status in normal pregnancy.

METHODS

The study population included non-pregnant women (n=31), healthy pregnant women in the first (n=50), second (n=51) and third (n=53) trimesters of gestation, and women in postpartum period (n=31). Additionally, samples from another twenty pregnant women were obtained in the three trimesters. Strontium, copper, selenium and zinc were measured by inductively coupled plasma-mass spectrometry. Calcium (Ca), uric acid (UA), lipid peroxidation and total antioxidant activity (TAA) were measured by spectrophotometric assays.

RESULTS

Strontium remained unchanged until the third trimester of pregnancy, in which significantly higher levels were found (p=0.001). The other elements showed diverse trends during pregnancy. Uric acid levels were significantly different in all groups (p<0.001), increasing gradually as the pregnancy progresses. In serial samples, there was a statistically significant positive correlation between Sr and gestational week of sampling (r=0.31, p=0.01), UA (r=0.40, p=0.001) and lipid peroxidation/TAA ratio (r=0.38, p=0.0002). Additionally, Sr correlated negatively with TAA (r=-0.40, p=0.0001).

CONCLUSION

Strontium seems to play a physiological role in the oxidative status of the human organism. Further studies involving Sr and pathologies of pregnancy are warranted.