Diagnostic accuracy of urinary spot protein:creatinine ratio for proteinuria in hypertensive pregnant women: systematic review

Hypertension Related Co-Morbidities and Complications in Women of Sub-Saharan Africa: A Brief Review

Hypertension is the leading cause of cardiovascular disease in women, and sub-Saharan African (SSA) countries have some of the highest rates of hypertension in the world. Expanding knowledge of causes, management, and awareness of hypertension and its co-morbidities worldwide is an effective strategy to mitigate its harms, decrease morbidities and mortality, and improve individual quality of life. Hypertensive disorders of pregnancy (HDPs) are a particularly important subset of hypertension, as pregnancy is a major stress test of the cardiovascular system and can be the first instance in which cardiovascular disease is clinically apparent. In SSA, women experience a higher incidence of HDP compared with other African regions. However, the region has yet to adopt treatment and preventative strategies for HDP. This delay stems from insufficient awareness, lack of clinical screening for hypertension, and lack of prevention programs. In this brief literature review, we will address the long-term consequences of hypertension and HDP in women. We evaluate the effects of uncontrolled hypertension in SSA by including research on heart disease, stroke, kidney disease, peripheral arterial disease, and HDP. Limitations exist in the number of studies from SSA; therefore, we will use data from countries across the globe, comparing and contrasting approaches in similar and dissimilar populations. Our review highlights an urgent need to prioritize public health, clinical, and bench research to discover cost-effective preventative and treatment strategies that will improve the lives of women living with hypertension in SSA.

A meta-analysis on diagnostic accuracy of spot urinary protein to creatinine ratio versus 12-h proteinuria in preeclampsia

To systematically review the diagnostic accuracy of spot urinary protein to creatinine ratio (PCR) and 12-h proteinuria in preeclampsia and to estimate which is a preferred alternative method for 24-h proteinuria, we carried out this meta-analysis. 25 primary studies were included based on searching strategy. For spot urinary PCR, our results showed pooled sensitivity of 87% (95% confidence interval [CI] 83%-91%) and specificity of 86% (95% CI 79%-91%), with an area under curve (AUC) of 0.93 (0.90-0.95). For 12-h proteinuria, pooled sensitivity and specificity were 92% (95% CI 87%-96%) and 99% (95% CI 75%-100%), respectively, with an AUC of 0.97 (0.95-0.98). Fagan plot and likelihood ratio scattergram showed that 12-h proteinuria yielded a better discriminatory performance on diagnosis of proteinuria (≥0.3 g/24 h). These results indicated that 12-h proteinuria estimation shows better clinical value than spot urine PCR for diagnosis of preeclampsia. However, due to the severity of condition and the fact that preeclampsia patients cannot wait for 12 h, spot urine PCR can be used as one of the diagnostic indicators.

[Preeclampsia: Guidelines for clinical practice from the French College of Obstetricians and Gynecologists]

OBJECTIVE

To identify strategies to reduce maternal and neonatal morbidity related to preeclampsia.

MATERIAL AND METHODS

The quality of evidence of the literature was assessed following the GRADE® method with questions formulated in the PICO format (Patients, Intervention, Comparison, Outcome) and outcomes defined a priori and classified according to their importance. An extensive bibliographic search was performed on PubMed, Cochrane, EMBASE and Google Scholar databases. The quality of the evidence was assessed (high, moderate, low, very low) and recommendations were formulated as a (i) strong, (ii) weak or (iii) no recommendation. The recommendations were reviewed in two rounds with external reviewers (Delphi survey) to select the consensus recommendations.

RESULTS

Preeclampsia is defined by the association of gestational hypertension (systolic blood pressure≥140mmHg and/or diastolic blood pressure≥90mmHg) and proteinuria≥0.3g/24h or a Proteinuria/Creatininuria ratio≥30mg/mmol occurring after 20 weeks of gestation. Data from the literature do not show any benefit in terms of maternal or perinatal health from implementing a broader definition of preeclampsia. Of the 31 questions, there was agreement between the working group and the external reviewers on 31 (100%). In general population, physical activity during pregnancy should be encouraged to reduce the risk of preeclampsia (Strong recommendation, Quality of the evidence low) but an early screening based on algorithms (Weak recommendation, Quality of the evidence low) or aspirin administration (Weak recommendation, Quality of the evidence very low) is not recommended to reduce maternal and neonatal morbidity related to preeclampsia. In women with preexisting diabetes or hypertension or renal disease, or multiple pregnancy, the level of evidence is insufficient to determine whether aspirin administration during pregnancy is useful to reduce maternal and perinatal morbidity (No recommendation, Quality of the evidence low). In women with a history of vasculo-placental disease, low dose of aspirin (Strong recommendation, Quality of the evidence moderate) at a dosage of 100-160mg per day (Weak recommendation, Quality of the evidence low), ideally before 16 weeks of gestation and not after 20 weeks of gestation (Strong recommendation, Quality of the evidence low) until 36 weeks of gestation (Weak recommendation, Quality of the evidence very low) is recommended. In a high-risk population, additional administration of low molecular weight heparin is not recommended (Weak recommendation, Quality of the evidence moderate). In case of preeclampsia (Weak recommendation, Quality of the evidence low) or suspicion of preeclampsia (Weak recommendation, Quality of the evidence moderate, the assessment of PlGF concentration or sFLT-1/PlGF ratio is not routinely recommended) in the only goal to reduce maternal or perinatal morbidity. In women with non-severe preeclampsia antihypertensive agent should be administered orally when the systolic blood pressure is measured between 140 and 159mmHg or diastolic blood pressure is measured between 90 and 109mmHg (Weak recommendation, Quality of the evidence low). In women with non-severe preeclampsia, delivery between 34 and 36+6 weeks of gestation reduces severe maternal hypertension but increases the incidence of moderate prematurity. Taking into account the benefit/risk balance for the mother and the child, it is recommended not to systematically induce birth in women with non-severe preeclampsia between 34 and 36+6 weeks of gestation (Strong recommendation, Quality of evidence high). In women with non-severe preeclampsia diagnosed between 37+0 and 41 weeks of gestation, it is recommended to induce birth to reduce maternal morbidity (Strong recommendation, Low quality of evidence), and to perform a trial of labor in the absence of contraindication (Strong recommendation, Very low quality of evidence). In women with a history of preeclampsia, screening maternal thrombophilia is not recommended (Strong recommendation, Quality of the evidence moderate). Because women with a history of a preeclampsia have an increased lifelong risk of chronic hypertension and cardiovascular complications, they should be informed of the need for medical follow-up to monitor blood pressure and to manage other possible cardiovascular risk factors (Strong recommendation, Quality of the evidence moderate).

CONCLUSION

The purpose of these recommendations was to reassess the definition of preeclampsia, and to determine the strategies to reduce maternal and perinatal morbidity related to preeclampsia, during pregnancy but also after childbirth. They aim to help health professionals in their daily clinical practice to inform or care for patients who have had or have preeclampsia. Synthetic information documents are also offered for professionals and patients.

Comparison of Urinary Protein/Creatinine Ratio as an Alternative to 24-h Proteinuria in Lupus Nephritis: TUNARI Study

BACKGROUND

Lupus nephritis (LN) occurs in approximately 50% of people with systemic lupus erythematosus (SLE). The 24-h proteinuria (gold standard) is measured among other tests for the control and monitoring of LN activity. This study investigates the use of the protein/creatinine ratio (PCR) as an alternative for the detection of proteinuria and its accuracy compared to the gold standard in a predominantly non-white population.

METHODS

This was a prospective study conducted in Salvador, Brazil, between December 2021 and May 2022. We invited adult patients diagnosed with SLE and LN, regardless of their disease activity. The estimation of the PCR and 24-h proteinuria was performed using conventional methods. The analysis used was Spearman's r correlation coefficient (rs), coefficient of determination (r2), and concordance by the Bland-Altman method. A specific sensitivity was measured by the ROC curve with its respective cut-off by the Youden Index.

RESULTS

We compared 112 samples of 75 patients with LN, with a mean age of 34.5 ± 11.8 years. Of these patients, 85% were women, 87.9% were non-white. A high degree of correlation was observed between PCR with 24-h proteinuria (rs = 0.77 and r2 = 0.59). The ROC analysis shows an area under the curve of 0.92 and the cut-off point calculated by the Youden Index was 0.78 with a sensitivity of 90.0% and specificity of 82%. However, the Bland-Altman graph indicated decreasing concordance as the degree of proteinuria increased, despite showing concordance at high levels of proteinuria.

CONCLUSION

The PCR shows high sensitivity to follow-up patients with LN when compared with 24-h proteinuria. Our findings suggest that PCR is a useful parameter for the evaluating and monitoring patients in complete remission. However, in cases of partial remission, the utility of PCR is limited.

Laboratory medicine in arterial hypertension

In the initial diagnostics of arterial hypertension (AH) laboratory medicine is a cornerstone, along with a blood pressure (BP) measurement and an electrocardiogram. It mainly refers to routine blood and urine tests for diagnosis and monitoring primary hypertension and its associated conditions such as asymptomatic hypertension-mediated organ damage, chronic kidney disease and hypertensive disorders of pregnancy. In addition, long term non-fatal and fatal risks for cardiovascular (CV) events in hypertension are assessed based on clinical and laboratory data. Furthermore, laboratory medicine is involved in the management of hypertension, especially in monitoring the disease progression. However, antihypertensive drugs may interfere with laboratory test results. Diuretics, especially thiazides, can affect blood and urine sodium concentrations, or angiotensin-converting enzyme inhibitors and angiotensin receptor blockers can affect the blood biomarkers of the renin-angiotensin-aldosterone system (RAAS). It's dysfunction plays a critical role in primary aldosteronism (PA), the most common endocrine disorder in secondary hypertension, which accounts for only small proportion of AH in relative terms but substantial proportion of hypertensives in absolute terms, affecting younger population and carrying a higher risk of CV mortality and morbidity. When screening for PA, aldosterone-to-renin ratio still contributes massively to the increased incidence of the disease, despite certain limits. In conclusion, laboratory medicine is involved in the screening, diagnosis, monitoring and prognosis of hypertension. It is of great importance to understand the preanalytical and analytical factors influencing final laboratory result.

Evaluation of cellophane as platform for colorimetric assays on microfluidic analytical devices

Due to their low cost, simplicity, and pump-free liquid transport properties, colorimetric assays on paper spots and microfluidic paper-based analytical devices (µPADs) are regarded as useful tools for point-of-care testing (POCT). However, for certain types of colorimetric assays, the "non-transparent" and "white" characters of paper can be a disadvantage. In this work, the possibilities of using cellophane as an alternative platform for colorimetric assays have been investigated. Cellophane is a low cost and easy-to-handle transparent film made of regenerated cellulose. Owing to its hydrophilic character, cellophane-based microfluidic channels fabricated through a print-cut-laminate approach enabled pump-free liquid transport into multiple detection areas, similar to µPADs. In addition, the water absorption characteristics of cellophane allowed the stable immobilization of water-soluble colorimetric indicators without any surface modification or additional reagents. The transparency of cellophane provides possibilities for simple background coloring of the substrates, increasing the dynamic signal range for hue-based colorimetric assays, as demonstrated for two model assays targeting H₂O₂ (46-fold increase) and creatinine (3.6-fold increase). Finally, a turbidity detection-based protein assay was realized on black background cellophane spots. The lowest limits of detection achieved with the cellophane-based devices were calculated as 7 µM for H₂O₂, 2.7 mg dL^-1 for creatinine, and 3.5 mg dL^-1 for protein (human serum albumin).

Clinical value and cost analysis of the sFlt-1/PlGF ratio in addition to the spot urine protein/creatinine ratio in women with suspected pre-eclampsia: PREPARE cohort study

BACKGROUND

This study investigated the clinical value of adding the sFlt-1/PlGF ratio to the spot urine protein/creatinine ratio (PCr) in women with suspected pre-eclampsia.

METHODS

This was a prospective cohort study performed in a tertiary referral centre. Based on the combination of PCr (< 30) and sFlt-1/PlGF (≤38) results, four groups were described: a double negative result, group A-/-; a negative PCr and positive sFlt-1/PlGF, group B-/+; a positive PCr and negative sFlt-1/PlGF, group C+/-; and a double positive result, group D+/+. The primary outcome was the proportion of false negatives of the combined tests in comparison with PCr alone in the first week after baseline. Secondary, a cost analysis comparing the costs and savings of adding the sFlt-1/PlGF ratio was performed for different follow-up scenarios.

RESULTS

A total of 199 women were included. Pre-eclampsia in the first week was observed in 2 women (2%) in group A-/-, 12 (26%) in group B-/+, 4 (27%) in group C+/-, and 12 (92%) in group D+/+. The proportion of false negatives of 8.2% [95% CI 4.9-13.3] with the PCr alone was significantly reduced to 1.6% [0.4-5.7] by adding a negative sFlt-1/PlGF ratio. Furthermore, the addition of the sFlt-1/PlGF ratio to the spot urine PCr, with telemonitoring of women at risk, could result in a reduction of 41% admissions and 36% outpatient visits, leading to a cost reduction of €46,- per patient.

CONCLUSIONS

Implementation of the sFlt-1/PlGF ratio in addition to the spot urine PCr, may lead to improved selection of women at low risk and a reduction of hospital care for women with suspected pre-eclampsia.

TRIAL REGISTRATION

Netherlands Trial Register (NL8308).

Cross-sectional diagnostic accuracy study of self-testing for proteinuria during hypertensive pregnancies: The UDIP study

OBJECTIVE

To determine the accuracy of self-testing for proteinuria during pregnancy.

DESIGN

Diagnostic accuracy study.

SETTING

Antenatal clinics, maternity assessment units and inpatient wards at three hospital sites.

POPULATION OR SAMPLE

345 pregnant women.

METHODS

Pregnant women self-tested in-clinic for urinary protein using visually read dipsticks with samples then sent for laboratory estimation of the spot protein-creatinine ratio (PCR) (primary reference test). Secondary index tests included testing by antenatal healthcare professionals and an automated colorimetric reader.

MAIN OUTCOME MEASURES

Sensitivity, specificity, negative predictive value, positive predictive value and likelihood ratios were calculated for self-testing (primary index test) along with healthcare professional and colorimetric testing compared to the primary reference test (PCR).

RESULTS

335/345 (97%) had sufficient data to be included in the analysis. Self-testing had a sensitivity of 0.71 (95% confidence interval [CI] 0.62-0.79) and a specificity of 0.89 (95% CI 0.84-0.92) compared to PCR. Sensitivity and specificity of testing by healthcare professionals and the colorimetric reader were similar: sensitivity 0.73 (95% CI 0.64-0.80) and 0.78 (95% CI 0.69-0.85), respectively; specificity 0.88 (95% CI 0.82-0.92) and 0.83 (95% CI 0.78-0.88), respectively.

CONCLUSION

Pregnant women can visually read a dipstick for urinary protein with similar accuracy to antenatal healthcare professionals. Automated colorimetric testing was not significantly different, in contrast to some previous studies. Self-testing has the potential to form part of a self-monitoring regime in pregnancy.

Benchmark dose in the presence of coexposure to melamine and diethylhexyl phthalate and urinary renal injury markers in pregnant women

Environmental exposures to mixtures of toxic chemicals have potential interaction effects that may lead to hazard index values exceeding one. However, current regulation levels, such as tolerable daily intake (TDI), are mostly based on experimental studies conducted with a single chemical compound. In this study, we assessed the relationships between melamine and di-(2-ethylhexyl) phthalate (DEHP) exposure and their coexposure with the early renal injury markers N-acetyl -D-glucosaminidase (NAG), albumin/creatinine ratio (ACR), and microalbuminuria in 1236 pregnant women. Various generalized linear models with interaction terms and Bayesian kernel machine regression models were used for the (co-)exposure response associations. We derived the benchmark dose (BMD) and the corresponding one-sided 95% confidence bound BMDL based on the estimated (covariate-adjusted) average daily intake of melamine and DEHP metabolites measured in spot urine of the women collected during the third trimester. Given a benchmark response of 0.1, the BMDL level of melamine (DEHP) exposure on NAG (ACR, microalbuminuria) was 2.67 (11.20, 4.45) μg/kg_bw/day, and it decreased to as low as 1.46 (3.83, 2.73) μg/kg_bw/day when considering coexposure to DEHP (melamine) up to the 90th percentile. Both the exposure threshold levels of melamine and DEHP for early renal injuries in pregnant women were several-fold to one order lower than the current recommended TDIs by the WHO and the US FDA and EPA and were even lower considering coexposure. Because of concurrent exposures in real-world environments, more stringent regulation levels are recommended in susceptible populations, such as pregnant women, due to potential synergistic mixture effects.

Enhanced SHP-1 Expression in Podocyturia Is Associated with Kidney Dysfunction in Patients with Diabetes

Background

Diabetic kidney disease (DKD) remains the leading cause of end stage kidney disease worldwide. Despite significant advances in kidney care, there is a need to improve noninvasive techniques to predict the progression of kidney disease better for patients with diabetes. After injury, podocytes are shed in urine and may be used as a biologic tool. We previously reported that SHP-1 is upregulated in the kidney of diabetic mice, leading to podocyte dysfunction and loss. Our objective was to evaluate the expression levels of SHP-1 in urinary podocytes and kidney tissues of patients with diabetes.

Methods

In this prospective study, patients with and without diabetes were recruited for the quantification of SHP-1 in kidney tissues, urinary podocytes, and peripheral blood monocytes. Immunochemistry and mass spectrometry techniques were applied for kidney tissues. Urinary podocytes were counted, and expression of SHP-1 and podocyte markers were measured by quantitative PCR.

Results

A total of 66 participants (diabetic n=48, nondiabetic n=18) were included in the analyses. Diabetes was associated with increased SHP-1 expression in kidney tissues (P=0.03). Nephrin and podocin mRNA was not significantly increased in urinary podocytes from patients with diabetes compared with those without diabetes, whereas levels of SHP-1 mRNA expression significantly correlated with HbA1c and estimated glomerular filtration rate (eGFR). Additionally, follow-up (up to 2 years post recruitment) evaluation indicated that SHP-1 mRNA expression continued to increase with eGFR decline.

Conclusions

Levels of SHP-1 in urinary podocytes may serve as an additional marker of glomerular disease progression in this population.

Second-Trimester Constituents of the Metabolic Syndrome and Pregnancy Outcome: An Observational Cohort Study

Background: Gestational diabetes mellitus (GDM) increases the risk of type 2 diabetes mellitus and cardiovascular disease (CVD) in women in later life. In the general population, metabolic syndrome (MetS) shows identical associations. The aim of this study was to evaluate the association between GDM, constituents of MetS and pregnancy outcomes. Methods: Of 2041 pregnant women undergoing an oral glucose tolerance test (OGTT) between 22 and 30 weeks of gestation, data were collected to evaluate the constituents of MetS. Odds ratios (ORs) were calculated to determine the associations between MetS and pregnancy outcomes. Results: GDM and obesity did not affect the risk of fetal growth abnormalities (SGA/LGA), preterm birth or preeclampsia (PE). Hypertension significantly increased the risk of SGA (OR—1.59), PE (OR—3.14), and preterm birth <37 weeks (OR—2.17) and <34 weeks (OR—2.96) and reduced the occurrence of LGA (OR—0.46). Dyslipidemia increased the risk of PE (OR—2.25), while proteinuria increased the risk of PE (OR—12.64) and preterm birth (OR—4.72). Having ≥2 constituents increased the risk of PE and preterm birth. Conclusions: Constituents of metabolic syndrome, rather than treating impaired glucose handling, increased the risk of preeclampsia, altered fetal growth and preterm birth. Obesity was not related to adverse outcomes.

Cognitive dysfunction and white matter hyperintensities in Fabry disease

Fabry disease (FD) is an X-linked lysosomal storage disorder with multi-system involvement including cerebrovascular disease. Patients with FD also have a high risk of ischaemic stroke and TIA. White matter hyperintensities are common, but their clinical impact on cognition remains uncertain. Previous studies have examined the neuropsychological profile of FD, but have been inconclusive in part due to methodological limitations including small sample sizes. We sought to address these limitations in a case-control study of 26 patients with Fabry disease with mild to moderate disease symptoms matched with 18 healthy controls for age and premorbid intellectual level. We obtained detailed neuropsychological data and MRI neuroimaging data on the severity of white matter changes. Mood was accounted for as a possible confounder. Our results showed significant compromise of executive functions and information processing speed for the FD group. Error analyses suggested that the compromise of executive functions could not be entirely accounted for by slowed information processing speed. We demonstrated significant correlations between cognitive decline and the overall volume of white matter hyperintensities in the FD group. Our results point to significant compromise of cognition in FD even without stroke or mood difficulties. This suggests that neuropsychological assessment and rehabilitation should be routinely offered to patients with FD.

Correlation between Random Urinary Protein-to-creatinine Ratio and 24-h Urinary Protein Excretion in Preeclampsia

This study aimed to determine the correlation between random urinary protein-to-creatinine ratio in single-voided urine samples and 24-h urinary protein excretion in pregnant women with preeclampsia. A cross-sectional study was conducted at the Department of Gynecology and Obstetrics, Abbasi Shaheed Hospital, Karachi, Pakistan, from July 2019 to June 2020. Fifty women with singleton pregnancy after 20 weeks of gestation with hypertension and 2+ proteinuria or more, according to a dipstick test, were included. Those with chronic hypertension; preexisting renal disease; gestational diabetes; eclampsia; hemolysis, elevated liver enzymes, a low platelet count syndrome; and coexisting urinary tract infections were excluded. Two random urine samples taken at 9:00 a.m. and 2:00 p.m. and 24-h urine samples were collected to evaluate the random urinary protein-to-creatinine and the 24-h protein excretion, respectively. The correlation coefficient (r) between them was calculated using Pearson's correlation test. The patients' mean age was 28.58 ± 5.09 years and their mean gestational age was 32.74 ± 4.44 weeks. Twenty-eight (56%) women were primigravidas, and 22 (44%) were multiparous. The average serum creatinine was 0.80 ± 0.16 mg/dL. The mean random urinary protein-to-creatinine ratio was 0.93 ± 0.7 mg/mg, and the mean 24-h urine was 481.08 ± 20.10 mL. A strong positive correlation was found between the protein-to-creatinine ratio and 24-h urinary protein excretion (r = 0.655; P = 0.01). We concluded that the protein-to-creatinine ratio in spot urine samples could be used as an alternative to in 24-h collection of urine to determine protein excretion in preeclamptic pregnant women.

Urinary Protein-to-Creatinine Ratio: An Indicator of Adverse Clinical Outcomes in Preeclampsia With Proteinuria

Background and objective

Preeclampsia is a major contributor to morbidity and mortality among pregnant women and leads to poor fetomaternal outcomes. Predicting fetal and maternal health outcomes will enable early interventions so as to reduce further damage. Various biochemical tests like beta-human chorionic gonadotropin (β-HCG), inhibin A, activin A, pregnancy-associated plasma protein-A (PAPP-A), fetal DNA, and color Doppler have been studied for their ability to predict fetal and maternal health outcomes; however, most of these tests are complex and costly. Among the many variables that indicate the severity of outcomes in hypertensive disorders of pregnancy, the urinary protein-to-creatinine ratio (UPCR) is an important index. The aim of the study was to find out the association between UPCR and fetomaternal outcomes in preeclampsia.

Material and methods

A prospective observational study was conducted among 141 women with preeclampsia presenting with proteinuria, who were divided into two groups: 11% with UPCR <0.3 and 89% with UPCR ≥0.3. These patients were followed up till delivery to look for maternal and fetal outcomes.

Results

The sensitivity of UPCR for predicting adverse maternal outcomes was 79.37% (95% CI: 71.25-86.06), specificity was 46.67% (95% CI: 21.27-73.41), positive predictive value (PPV) was 92.59% (95% CI: 88.53-95.29), negative predictive value (NPV) was 21.21% (95% CI: 12.43-33.81), and the accuracy was 75.79% (95% CI: 67.97-82.69); for adverse fetal outcomes, the sensitivity was 76.98% (95% CI: 68.65-84.01), specificity was 13.33% (95% CI: 1.66-40.46), PPV was 88.18% (95% CI: 85.69-90.29), NPV was 6.45% (95% CI: 1.79-20.67), and the accuracy was 70.21% (95% CI: 61.94-77.62).

Conclusion

Based on our findings, UPCR is a simple laboratory tool that can help predict abnormal fetomaternal outcomes in preeclampsia with good sensitivity and PPV and can be used as an adjunct to assist in clinical decisions.

Vibrational Spectroscopy: A Valuable Screening and Diagnostic Tool for Obstetric Disorders?

Preeclampsia (PE) is a common obstetric disorder typically affecting 2–8% of all pregnancies and can lead to several adverse obstetric outcomes for both mother and fetus with the greatest burden of severe outcomes in low middle-income countries (LMICs), therefore, screening for PE is vital. Globally, screening is based on maternal characteristics and medical history which are nonspecific for the disorder. In 2004, the World Health Organization acknowledged that no clinically useful test was able to predict the onset of PE, which prompted a universal search for alternative means of screening. Over the past decade or so, emphasis has been placed on the use of maternal characteristics in conjunction with biomarkers of disease combined into predictive algorithms, however these are yet to transition into the clinic and are cost prohibitive in LMICs. As a result, the screening paradigm for PE remains unchanged. It is evident that novel approaches are needed. Vibrational spectroscopy, specifically Raman spectroscopy and Fourier-transform infrared spectroscopy (FTIR), could provide better alternatives suited for implementation in low resource settings as no specialized reagents are required for conventional approaches and there is a drive to portable platforms usable in both urban and rual community settings. These techniques are based on light scattering and absorption, respectively, allowing detailed molecular analysis of samples to produce a unique molecular fingerprint of diseased states. The specificity of vibrational spectroscopy might well make it suited for application in other obstetric disorders such as gestational diabetes mellitus and obstetric cholestasis. In this review, we summarize current approaches sought as alternatives to current screening methodologies and introduce how vibrational spectroscopy could offer superior screening and diagnostic paradigms in obstetric care. Additionally, we propose a real benefit of such tools in LMICs where limited resources battle the higher prevalence of obstetric disorders.

Pre-eclampsia

Pre-eclampsia is a multisystem pregnancy disorder characterised by variable degrees of placental malperfusion, with release of soluble factors into the circulation. These factors cause maternal vascular endothelial injury, which leads to hypertension and multi-organ injury. The placental disease can cause fetal growth restriction and stillbirth. Pre-eclampsia is a major cause of maternal and perinatal mortality and morbidity, especially in low-income and middle-income countries. Prophylactic low-dose aspirin can reduce the risk of preterm pre-eclampsia, but once pre-eclampsia has been diagnosed there are no curative treatments except for delivery, and no drugs have been shown to influence disease progression. Timing of delivery is planned to optimise fetal and maternal outcomes. Clinical trials have reported diagnostic and prognostic strategies that could improve fetal and maternal outcomes and have evaluated the optimal timing of birth in women with late preterm pre-eclampsia. Ongoing studies are evaluating the efficacy, dose, and timing of aspirin and calcium to prevent pre-eclampsia and are evaluating other drugs to control hypertension or ameliorate disease progression.

Protein-creatinine ratio and albumin-creatinine ratio for the diagnosis of significant proteinuria in pregnant women with hypertension: Systematic review and meta-analysis of diagnostic test accuracy

BACKGROUND

The gold standard for assessment and diagnosis of significant proteinuria in pregnancy has been by 24-hour urine collection and analysis. Determining fast, accurate methods to identify clinically significant proteinuria would aid diagnosis of pre-eclampsia. The objective of this study was to determine the accuracy of spot protein-creatinine ratio (PCR) and albumin-creatinine ratio (ACR) measurements compared with 24-hour urine collection for the identification of clinically significant proteinuria in women with hypertensive disorders of pregnancy.

METHODS

Search strategies were developed for electronic databases from inception to 1st October 2020. Data were assessed for methodological quality using the QUADAS-II checklist for risk of bias and quality of the evidence using GRADE. Meta-analysis was performed where there were at least four studies presenting data for the same comparison (test and threshold). This is an update of the review for NICE guideline NG133 (published June 2019) and includes additional data.

RESULTS

Twenty-nine studies were included. PCR measurements (28 studies) showed high sensitivity (91%) and specificity (89%) at a threshold of 30 mg/mmol (n = 3577). Higher thresholds (>60 mg/mmol) increased specificity, but reduced sensitivity. At a threshold of PCR 30 mg/mmol, diagnostic accuracy improved for sensitivity and specificity (93% for both) in studies where the first morning void was excluded (n = 1868). Data available (4 studies) for ACR supports ruling out of significant proteinuria at less than 2 mg/mmol, though evidence was limited by paucity of data and wide confidence intervals around the result.

CONCLUSIONS

PCR and ACR have high accuracy compared to the gold standard 24-hour urine collection.

Association between two common environmental toxicants (phthalates and melamine) and urinary markers of renal injury in the third trimester of pregnant women: The Taiwan Maternal and Infant Cohort Study (TMICS)

BACKGROUND

Exposure to either melamine or phthalate, two common toxicants, during pregnancy may cause adverse health effects, including kidney damage.

OBJECTIVES

We investigated the independent and interactive effect of exposure to melamine and phthalates, particularly di-(2-ethylhexyl) phthalate (DEHP), on markers of early renal injury in women their third trimester of pregnancy in one nationwide birth cohort, the Taiwan Maternal and Infant Cohort Study (TMICS).

METHODS

Between October, 2012 and May, 2015, participants were administered questionnaires, physical examinations, and blood and urine tests during their third trimester. One-spot overnight urine specimens were used to simultaneously measure melamine, 11 phthalate metabolites, and two markers of renal injury, microalbumin and N-acetyl-beta-D-glucosaminidas (NAG). Estimated daily DEHP intake was calculated based on measurement of three urinary DEHP metabolites. Microalbuminuria was defined as having a urinary albumin/creatinine ratio (ACR) higher than 3.5 mg/mmol.

RESULTS

Total 1433 pregnant women were analyzed. The median value for urinary melamine was 0.63 μg/mmol Cr and estimated DEHP intake was 1.84 μg/kg/day. We found subjects in the highest quartile of estimated DEHP intake to have significantly higher urinary ACR (β = 0.095, p = 0.043) and the prevalence of microalbuminuria (adjusted OR = 1.752, 95% confidence interval = 1.118-2.746), compared to those in the lowest quartile. In addition, there was a significant interactive effect between urinary melamine and estimated DEHP intake on urinary ACR and NAG.

CONCLUSION

Our results suggest these two ubiquitous chemicals together may be associated with markers of early kidney injury in pregnant women.

Diagnostic accuracy of random urinary protein-to-creatinine ratio for proteinuria in patients with suspected pre-eclampsia

PURPOSE

To evaluate the correlation between urine protein/creatinine ratio (UPCR) and proteinuria in a 24-h urine collection and to calculate the predicative accuracy of different cutoffs of UPCR for the diagnosis of proteinuria.

METHODS

A retrospective cohort study including women who admitted for the evaluation for suspected preeclampsia (PET) beyond 20 weeks of gestation in a single tertiary center. Both UPCR test and quantification of proteinuria using 24-h urine collection were obtained during their index hospitalization no more than 48 h apart. Women with pre-existing diabetes mellitus, known renal disease or proteinuria prior to pregnancy or chronic hypertension were excluded. Predictive accuracy of UPCR for several cutoffs of proteinuria was evaluated. Multivariate logistic regression analysis was used to assess diagnostic accuracy of UPCR in sub-populations according to obstetrical characteristics.

RESULTS

Overall 463 patients were included. Of them 316 (68.3%) have 24-h urine protein collection of ≥ 300 mg/day. Mean gestational age at evaluation was 34.0 ± 3.4 weeks. Median (and interquartile range) time interval between UPCR and 24-h urine collection was 1.8 (1.6-1.9) days. Sensitivity and specificity of UPCR of 0.3 for predicting proteinuria ≥ 300 mg/day were 90.1% and 63.3%, respectively. The corresponding values for difference proteinuria cutoffs: ≥ 1000 mg/day and 5000 mg/day were 98.4, 100% and 29.1, 36.0%, respectively. The optimal UPCR thresholds for 24-h urine protein collection of ≥ 300 mg/day,  ≥ 1000 mg/day and 5000 mg/day were 0.31, 0.70 and 2.49, respectively. The predictive accuracy of UPCR > 0.30 in predicting proteinuria was unaffected by demographic and obstetrical characteristics as maternal age, pre-pregnancy BMI, gestational age at examination, creatinine levels or by multiple gestation [adjusted OR 18.27 (95% CI 9.97-33.47)].

CONCLUSION

UPCR was strongly correlated with various cutoffs of proteinuria obtained by 24-h urine collection. UPCR cutoff varied depending on the specific measured outcome. This correlation was not affected by gestational age at examination.

Preeclampsia and Kidney Disease: Deciphering Cause and Effect

PURPOSE OF REVIEW

Preeclampsia and chronic kidney disease have a complex, bidirectional relationship. Women with kidney disease, with even mild reductions in glomerular filtrate rate, have an increased risk of developing preeclampsia. Preeclampsia, in turn, has been implicated in the subsequent development of albuminuria, chronic kidney disease, and end-stage kidney disease. We will discuss observational evidence and mechanisms linking the two disease processes.

RECENT FINDINGS

Preeclampsia is characterized by an imbalance in angiogenic factors that causes systemic endothelial dysfunction. Chronic kidney disease may predispose to the development of preeclampsia due to comorbid conditions, such as hypertension, but is also associated with impaired glycocalyx integrity and alterations in the complement and renin-angiotensin-aldosterone systems. Preeclampsia may lead to kidney disease by causing acute kidney injury, endothelial damage, and podocyte loss. Preeclampsia may be an important sex-specific risk factor for chronic kidney disease. Understanding how chronic kidney disease increases the risk of preeclampsia from a mechanistic standpoint may open the door to future biomarkers and therapeutics for all women.

Comparisons of Dipstick Test, Urine Protein-to-Creatine Ratio, and Total Protein Measurement for the Diagnosis of Preeclampsia

Preeclampsia affects 2–5% of pregnant women and is one of the leading causes of maternal and perinatal morbidity and mortality. We aimed to extensively evaluate proteinuria in women with preeclampsia and to determine the analytical sensitivity and specificity of and the cutoff values for urine protein-to-creatinine ratio (UPCR) and total protein in 24 h urine samples. This study included 88 women. We used the urine dipstick test, UPCR, and total protein measurement in a 24 h urine sample. The patients were divided in gestational hypertension (GH, n = 44) and preeclampsia (PE, n = 44) groups. In the GH group, 25% (11/44) of the patients presented incidentally positive results. UPCR and total protein in 24 h urine specimens were increased in the GH group compared to the PE group. Receiver operating characteristic analysis showed a UPCR cutoff of 30 mg/mmol as significant for preeclampsia, while the sensitivity and specificity were 89% (95% CI, 75–97) and 100% (95% CI, 87–100), respectively. In the 24 h urine protein test, sensitivity and specificity were 80% (95% CI, 61–92) and 100% (95% CI, 88–100), respectively, for the cutoff value of 0.26 g/24 h. In comparison to the other commonly used tests here considered, UPCR determination is a reliable, relatively faster, and equally accurate method for the quantitation of proteinuria, correlates well with 24 h urine protein estimations, and could be used as an alternative to the 24 h proteinuria test for the diagnosis of preeclampsia.

Spot urine protein-to-creatinine ratio as a diagnostic test in pre-eclampsia: A gold standard?

OBJECTIVE

To determine the diagnostic accuracy and optimal threshold of the spot protein-to-creatinine ratio (PCR) compared to the gold standard, 24-hour proteinuria (24HP) in patients with suspected pre-eclampsia.

METHODS

A prospective observational study was performed from June 2015 to May 2017 consisting of patients hospitalized for suspected pre-eclampsia in a tertiary care referral center. To compare the two diagnostic tests, a spot urine sample was obtained to perform the PCR before starting the collection of the 24HP. Only patients who had both tests were analyzed.

RESULTS

In total, 148 patients (216 samples) were included. The two tests were highly correlated (r=0.80, P<0.001). The receiver operating characteristic curve analysis and the area under the curve (AUC=0.92) highlighted the accuracy of PCR in diagnosing significant proteinuria and thus pre-eclampsia. The optimal cut-off using the Liu method was 56.9 mg/mmol (sensitivity=79.3%, specificity=91.5%).

CONCLUSION

The results suggest that PCR could replace 24HP when diagnosing proteinuria in pre-eclampsia. Moreover, it is a simple test, easy to realize and standardize, and cheap with no need for systematic hospitalization. The best cut-off should be chosen by thinking about the risks for adverse maternal and/or fetal outcomes. The test may help to optimize medical care in pre-eclampsia worldwide.

Preeclampsia: Risk Factors, Diagnosis, Management, and the Cardiovascular Impact on the Offspring

Hypertensive disorders of pregnancy affect up to 10% of pregnancies worldwide, which includes the 3%–5% of all pregnancies complicated by preeclampsia. Preeclampsia is defined as new onset hypertension after 20 weeks’ gestation with evidence of maternal organ or uteroplacental dysfunction or proteinuria. Despite its prevalence, the risk factors that have been identified lack accuracy in predicting its onset and preventative therapies only moderately reduce a woman’s risk of preeclampsia. Preeclampsia is a major cause of maternal morbidity and is associated with adverse foetal outcomes including intra-uterine growth restriction, preterm birth, placental abruption, foetal distress, and foetal death in utero. At present, national guidelines for foetal surveillance in preeclamptic pregnancies are inconsistent, due to a lack of evidence detailing the most appropriate assessment modalities as well as the timing and frequency at which assessments should be conducted. Current management of the foetus in preeclampsia involves timely delivery and prevention of adverse effects of prematurity with antenatal corticosteroids and/or magnesium sulphate depending on gestation. Alongside the risks to the foetus during pregnancy, there is also growing evidence that preeclampsia has long-term adverse effects on the offspring. In particular, preeclampsia has been associated with cardiovascular sequelae in the offspring including hypertension and altered vascular function.

Pregnancy in Women With Systemic Lupus and Lupus Nephritis

Pregnancy is an altered immunologic state in which hormonal changes impact the immune system to enable maternal tolerance of the fetus. These hormonal and immunologic changes may affect disease activity in systemic lupus erythematosus. Conversely, lupus nephritis and its complications may adversely impact pregnancy. Systemic lupus erythematosus increases the risk of pre-eclampsia and its complications, including preterm birth and intrauterine growth restriction. Comorbidities such as impaired kidney function and hypertension confer additional risk and complexity. Medications used to treat lupus nephritis may impact the fetus, so therapy needs to be tailored to balance maternal benefit and fetal risk. The diagnosis of lupus nephritis during pregnancy can be difficult, as it shares overlapping features with pre-eclampsia. Kidney biopsy is generally safe in pregnancy, and should be considered if the result will affect management. Here we review the clinical aspects of counseling, diagnosis, and management of lupus nephritis in pregnancy.

Association of High Levels of Spot Urine Protein with High Blood Pressure, Mean Arterial Pressure and Pulse Pressure with the Development of Diabetic Chronic Kidney Dysfunction or Failure among Diabetic Patients. Statistical Regression Modeling to Predict Diabetic Proteinuria

INTRODUCTION

In research elevated Blood Pressure (BP) has been demonstrated to be a risk for the development of nephropathy and chronic renal disease (CKD) Or Diabetic Kidney Disease (DKD) among diabetics. However, no study has find correlation for the spot urine protein (UPr) excretion with elevated BP, Pulse Pressure (PP) and mean arterial pressure MAP). This technique was invented in the current study.

METHODS

10,270 were recruited for more than 12 years. Demographically, 43%, 38%, and 16% showed hypertension, nephropathy and chronic renal disease, respectively. UPr demonstrated significant correlations with systolic BP (SBP) and diastolic BP (DPB), MAP and PP (p < 0.0001 for all). SBP, DBP, PP and MAP, UPr were observed to be higher among the groups with nephroaphty and CKD/DKD with highly significant p-values (all p < 0.05). With logistic regression, odds ratio of hypertension (HTN) with nephropathy was observed to be 2.99 (95% CI 2.44 to 3.7; p < 0.0001); and odds ratio of HTN with CKD/DK was 7.1 (95% CI 4.3 to 11.84; p<0.0001), indicating that HTN significantly contributes to the development of nephropathy and CKD/DKD in diabetics.

RESULTS

Invented regression models for the excretion of UPr from the kidney with elevated SBP, DBP, MAP and PP were highly significant (p < 0.0001 for all); UPr = -138.6 + [1.347 × SBP] ; UPr = -93.4 + [1.62 × DBP] ; UPr = -149.5 + [1.922 × MAP] ; UPr = -41.23 +[1.541 × PP].

CONCLUSION

Current study is the first one to introduce this technique. These invented new equations can be used by physicians to estimate protein excretion in urine at bedside and outpatients departments for monitoring proteinuria and CKD/DKD.

The management of hypertension in women planning for pregnancy

INTRODUCTION OR BACKGROUND

Poorly-controlled hypertension in the first trimester significantly increases maternal and fetal morbidity and mortality. The majority of guidelines and clinical trials focus on the management and treatments for hypertension during pregnancy and breast-feeding, while limited evidence could be applied to the management for hypertension before pregnancy. In this review, we summarized the existing guidelines and treatments of pre-pregnancy treatment of hypertension.

SOURCES OF DATA

PubMed.

AREAS OF AGREEMENT

Methyldopa and labetalol are considered the first choice, but angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) need to be withdrawn if a hypertensive woman wishes to become pregnant. In women with chronic hypertension, it is very important to make an assessment before conception to exclude secondary causes of hypertension, evaluate their hypertensive control to ensure that it is optimal, discuss the increased risks of pre-eclampsia, and provide education regarding any drug alterations before they become pregnant.

AREAS OF CONTROVERSY

There is increasing debate regarding discouraging the use of diuretics. There is also controversy regarding the use of supplementations such as calcium, antioxidants and low-dose aspirin.

GROWING POINTS

A less restricted blood-pressure goal could be set for hypertensive women planning for pregnancy. A healthy body weight before pregnancy could lower the risk of pregnancy-related hypertensive disorders. Recent guidelines also encourage women with chronic hypertension to keep their dietary sodium intake low, either by reducing or substituting sodium salt before pregnancy.

TIMELY AREAS FOR DEVELOPING RESEARCH

Large, worldwide, randomized trials should be conducted to see the outcomes for hypertensive women who take antioxidants/physical activity before pregnancy.

Analysis of Proteinuria Estimation Methods in Hypertensive Disorders of Pregnancy

Purpose of the Study

The gold-standard 24-h urine collection method for protein estimation is inconvenient and is associated with a delay in laboratory analysis. This study was undertaken to compare sulphosalicylic acid test, urine dipstick test, urine protein-to-creatinine ratio with 24-h urine protein estimation in pre-eclampsia cases.

Methods

This is a comparative study and consists of a single group of 764 subjects. This study was conducted in the Department of Obstetrics and Gynaecology in collaboration with the Department of Biochemistry, JIPMER, Pondicherry, India, from February 2011 to January 2014. The subjects included were 764 pre-eclampsia women. A first voided morning sample was obtained for sulphosalicylic acid test, dipstick test, urine protein and creatinine estimation and urine culture, and subsequent urine samples were collected for the 24-h urine protein estimation.

Main Findings

For significant proteinuria, sulphosalicylic acid test with 1 + proteinuria has sensitivity, specificity, PPV and NPV of 59, 48, 39, 67, whereas with 2 + has sensitivity, specificity,PPV and NPV of 44, 88, 75 and 67%, respectively, dipstick test with 1 + proteinuria has sensitivity, specificity, PPV and NPV of 71, 52, 54 and 70%, whereas with 2 + has sensitivity, specificity,PPV and NPV of 49, 87, 75 and 69%, respectively. The spot urine protein-to-creatinine ratio and 24-h urine protein were significantly correlated (r = 0.98; p < 0.0001). The cut-off value for the protein-to-creatinine ratio as an indicator of protein excretion ≥ 300 mg/day was 0.285. The sensitivity, specificity PPV and NPV were 100, 99, 100 and 99%, respectively.

Conclusion

The spot urine protein-to-creatinine ratio is a better method for estimation of proteinuria in pre-eclampsia.

Arterial stiffness is associated with target organ damage in subjects with pre-hypertension

INTRODUCTION

Present study was to evaluate whether increased arterial stiffness was associated with target organ damage in pre-hypertensive subjects.

MATERIAL AND METHODS

Pre-hypertensive subjects enrolled and echocardiography was used to evaluate left ventricular hypertrophy (LVH) and the first morning urine was collected to evaluate albumin and creatinine ratio (ALB/Cr ratio). Carotid-femoral pulse wave velocity (cf-PWV) was measured.

RESULTS

A total of 420 subjects were recruited and mean age was 42.6 years. Mean systolic/diastolic blood pressure (SBP/DBP) were 130 ±9 mm Hg and 85 ±4 mm Hg. The prevalence of albuminuria and left ventricular hypertrophy was 8.6 % and 11.7 %. Mean cf-PWV was 9.2 ±1.0 m/s, with arterial stiffness prevalence was 8.8%. Subjects with arterial stiffness had higher cf-PWV value (10.6 ±0.4 m/s vs. 8.7 ±0.6 m/s, p < 0.05), and ALB/Cr ratio (28.3 ±13.2 µg/mg vs. 23.1 ± 11.4 µg/mg, p < 0.05). Overall, with multivariate regression analysis, aging and arterial stiffness were significantly associated with pre-hypertension. With stepwise adjusted for potential covariates including age, male gender, fasting plasma glucose, presence of current cigarette smoking, dyslipidemia, statins and SBP, increased cf-PWV remained independently associated with left ventricular hypertrophy and albuminuria, with an increased odds of 41 % and 24 % (p < 0.05), respectively.

CONCLUSIONS

In pre-hypertensive subjects, arterial stiffness is independently associated with LVH and albuminuria and cf-PWV may be a useful marker to identify target organ damage in pre-hypertensive subjects.

Spot protein-creatinine ratio and spot albumin-creatinine ratio in the assessment of pre-eclampsia: a diagnostic accuracy study with decision-analytic model-based economic evaluation and acceptability analysis

BACKGROUND

The National Institute for Health and Care Excellence (NICE) guidelines highlighted the need for 'large, high-quality prospective studies comparing the various methods of measuring proteinuria in women with new-onset hypertensive disorders during pregnancy'.

OBJECTIVES

The primary objective was to evaluate quantitative assessments of spot protein-creatinine ratio (SPCR) and spot albumin-creatinine ratio (SACR) in predicting severe pre-eclampsia (PE) compared with 24-hour urine protein measurement. The secondary objectives were to investigate interlaboratory assay variation, to evaluate SPCR and SACR thresholds in predicting adverse maternal and fetal outcomes and to assess the cost-effectiveness of these models.

DESIGN

This was a prospective diagnostic accuracy cohort study, with decision-analytic modelling and a cost-effectiveness analysis.

SETTING

The setting was 36 obstetric units in England, UK.

PARTICIPANTS

Pregnant women (aged ≥ 16 years), who were at > 20 weeks' gestation with confirmed gestational hypertension and trace or more proteinuria on an automated dipstick urinalysis.

INTERVENTIONS

Women provided a spot urine sample for protein analysis (the recruitment sample) and were asked to collect a 24-hour urine sample, which was stored for secondary analysis. A further spot sample of urine was taken immediately before delivery.

MAIN OUTCOME MEASURES

Outcome data were collected from hospital records. There were four index tests on a spot sample of urine: (1) SPCR test (conducted at the local laboratory); (2) SPCR test [conducted at the central laboratory using the benzethonium chloride (BZC) assay]; (3) SPCR test [conducted at the central laboratory using the pyrogallol red (PGR) assay]; and (4) SACR test (conducted at the central laboratory using an automated chemistry analyser). The comparator tests on 24-hour urine collection were a central test using the BZC assay and a central test using the PGR assay. The primary reference standard was the NICE definition of severe PE. Secondary reference standards were a clinician diagnosis of severe PE, which is defined as treatment with magnesium sulphate or with severe PE protocol; adverse perinatal outcome; one or more of perinatal or infant mortality, bronchopulmonary dysplasia, necrotising enterocolitis or grade III/IV intraventricular haemorrhage; and economic cost and outcomes. Health service data on service use and costs followed published economic models.

RESULTS

In total, 959 women were available for primary analysis and 417 of them had severe PE. The diagnostic accuracy of the four assays on spot urine samples against the reference standards was similar. The three SPCR tests had sensitivities in excess of 90% at prespecified thresholds, with poor specificities and negative likelihood ratios of ≥ 0.1. The SACR test had a significantly higher sensitivity of 99% (confidence interval 98% to 100%) and lower specificity. Receiver operating characteristic (ROC) curves were similar (area under ROC curve between 0.87 and 0.89); the area under the central laboratory's SACR curve was significantly higher (p = 0.004). The central laboratory's SACR test was the most cost-effective option, generating an additional 0.03 quality-adjusted life-years at an additional cost of £45.07 compared with the local laboratory's SPCR test. The probabilistic analysis showed it to have a 100% probability of being cost-effective at the standard willingness-to-pay threshold recommended by NICE.

LIMITATIONS

Implementation of NICE guidelines has led to an increased intervention rate in the study population that affected recruitment rates and led to revised sample size calculations.

CONCLUSIONS

Evidence from this clinical study does not support the recommendation of 24-hour urine sample collection in hypertensive pregnant women. The SACR test had better diagnostic performance when predicting severe pre-eclampsia. All four tests could potentially be used as rule-out tests for the NICE definition of severe PE.

FUTURE WORK

Testing SACR at a threshold of 8 mg/mmol should be studied as a 'rule-out' test of proteinuria.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN82607486.

FUNDING

This project was funded by the National Institute Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 61. See the NIHR Journals Library website for further project information.

A review of blood pressure measurement in obese pregnant women

Blood pressure monitoring is a critical component of antenatal, peripartum and postnatal care. The accurate detection and treatment of abnormal blood pressure during pregnancy is essential for the optimisation of maternal and neonatal outcomes. Increasing maternal obesity in western populations is well documented. The presence of a large arm circumference in obese pregnant women may lead to difficult and inaccurate blood pressure measurements. Difficulties measuring blood pressure in non-pregnant obese patients are well described. In the literature, the problem is uncommonly mentioned in relation to pregnant patients. This topic review will discuss the importance and challenges of blood pressure measurement in pregnancy. The currently available equipment for blood pressure monitoring in pregnancy will be identified and the process of validating devices described. The limitations of the current validation protocols in pregnancy will be highlighted. It is concluded that a pregnancy-specific validation protocol is required: this would facilitate the introduction of new technology for use in high-risk pregnant women. More accurate blood pressure measurement has the potential to improve the diagnosis and management of abnormal blood pressure in pregnancy and influence maternal and neonatal outcomes.

Biomarkers of glomerular dysfunction in pre-eclampsia - A systematic review

BACKGROUND

Early detection of pre-eclampsia remains one of the major focuses of antenatal obstetric care. There is often a delay in the diagnosis, mainly due to the non-specific nature of the condition. Podocytes which play a pivotal role in glomerular function become injured in pre-eclampsia leading to subsequent proteinuria. Our aim was to review available studies to determine the clinical utility of biomarkers of podocyte injury in pre-eclampsia.

METHODS

We used QUADAS (Quality Assessment of Diagnostic Accuracy Studies) criteria to perform a systematic review of the literature to determine the clinical utility of podocyte injury biomarkers in predicting pre-eclampsia.

RESULTS

This study identified five potential renal biomarkers including podocytes, nephrin, synaptopodin, podocin and podocalyxin. The pooled sensitivity of all biomarkers was 0.78 (95% CI 0.74-0.82) with a specificity of 0.82 (95% CI 0.79-0.85). The area under the Summary of Receiver Operating Characteristics Curve (SROC) was 0.926 (SE 0.30). Urinary nephrin achieved the highest diagnostic values with a sensitivity of 0.81 (95% CI 0.72-0.88) and specificity of 0.84 (95% CI 0.79-0.84).

CONCLUSION

Biomarkers of glomerular injury show promise as diagnostic aids in pre-eclampsia. A large-scale prospective cohort study is warranted before these biomarkers can be recommended for routine clinical care.

Chronic hypertension in pregnancy: impact of ethnicity and superimposed preeclampsia on placental, endothelial, and renal biomarkers

Black ethnicity is associated with worse pregnancy outcomes in women with chronic hypertension. Preexisting endothelial and renal dysfunction and poor placentation may contribute, but pathophysiological mechanisms underpinning increased risk are poorly understood. This cohort study aimed to investigate the relationship between ethnicity, superimposed preeclampsia, and longitudinal changes in markers of endothelial, renal, and placental dysfunction in women with chronic hypertension. Plasma concentrations of placental growth factor (PlGF), syndecan-1, renin, and aldosterone and urinary angiotensinogen-to-creatinine ratio (AGTCR), protein-to-creatinine ratio (PCR), and albumin-to-creatinine ratio (ACR) were quantified during pregnancy and postpartum in women with chronic hypertension. Comparisons of longitudinal biomarker concentrations were made using log-transformation and random effects logistic regression allowing for gestation. Of 117 women, superimposed preeclampsia was diagnosed in 21% ( n = 25), with 24% ( n = 6) having an additional diagnosis of diabetes. The cohort included 63 (54%) women who self-identified as being of black ethnicity. PlGF concentrations were 67% lower [95% confidence interval (CI) -79 to -48%] and AGTCR, PCR, and ACR were higher over gestation, in women with subsequent superimposed preeclampsia (compared with those without superimposed preeclampsia). PlGF <100 pg/ml at 20-23.9 wk of gestation predicted subsequent birth weight <3rd percentile with 88% sensitivity (95% CI 47-100%) and 83% specificity (95% CI 70-92%). Black women had 43% lower renin (95% CI -58 to -23%) and 41% lower aldosterone (95%CI -45 to -15%) concentrations over gestation. Changes in placental (PlGF) and renal (AGTCR/PCR/ACR) biomarkers predated adverse pregnancy outcome. Ethnic variation in the renin-angiotensin-aldosterone system exists in women with chronic hypertension in pregnancy and may be important in treatment selection.

Diagnostic accuracy of spot albumin creatinine ratio and its association with fetomaternal outcome in preeclampsia and eclampsia

Introduction:

Hypertensive disorders in pregnancy are one of the leading causes of maternal and perinatal mortality. Proteinuria is one of the common and important features of preeclampsia. To evaluate the diagnostic accuracy of albumin-creatinine ratio (ACR) in woman with preeclampsia and eclampsia and examine the association between ACR and fetomaternal outcome.

Materials and Methods:

Prospective study carried out over a period of 1 year in the Department of Obstetrics and Gynaecology, after informed consent and ethical clearance total ninety pregnant women from gestational age 20 to 40 weeks were enrolled, including, thirty preeclampsia, thirty antepartum eclampsia, considered as cases and thirty normotensive pregnant women as controls. Preeclampsia was defined as per National High Blood Pressure Education Program 2000 working group. All patients were asked for a spot midstream urine sample, followed by 24 h urine collection. Urinary protein was estimated by the sulfosalicylic acid method and creatinine by the Jaffe's method. The urinary ACR was determined by automated analyzer.

Results:

Mean value of urinary ACR of controls was significantly lower (0.103 ± 0.037) as compared to both groups. On comparing between groups the difference was significant (<0.001), a strong correlation between urinary ACR levels and 24 h urinary proteins was observed.

Conclusion:

In our study, an association of raised ACR values with severity of disease as well as with adverse fetomaternal outcome was observed.

Spot urine protein measurements in normotensive pregnancies, pregnancies with isolated proteinuria and preeclampsia

We performed a prospective, longitudinal study of pregnant women presenting to their first obstetrics visits to characterize the changes in spot urine protein-to-creatinine (UPCR) and albumin-to-creatinine ratios (UACR) in normotensive pregnancies, as well as identify clinical characteristics associated with isolated proteinuria and preeclampsia. We measured spot urinary albumin, protein, and creatinine at the first prenatal visit, end of the second trimester, and at delivery. In the normotensive pregnancies (n = 142), we found that from the beginning of pregnancy to delivery, UACR increased by a median [interquartile range (IQR)] of 14.7 mg/g Cr (3.74-51.8) and UPCR by 60 mg/g Cr (30-130) (P < 0.001 for both changes). Isolated proteinuria (defined as UPCR > 300 mg/g Cr in the absence of hypertension) was identified in 19/142 (13.4%) normotensive pregnancies. Increases in systolic and diastolic blood pressure from early pregnancy to delivery and increases in UACR from early to midpregnancy were associated with isolated proteinuria at delivery. Twelve women developed preeclampsia. Nulliparity, early, and midpregnancy diastolic blood pressures were strongly associated with the development of preeclampsia, but early changes in UACR were not. In conclusion, women who develop isolated proteinuria at delivery have a larger increase in blood pressure than women without proteinuria and have a "microalbuminuric" phase earlier in gestation, unlike women who develop preeclampsia. These findings suggest a different mechanism of urine protein excretion in women with isolated proteinuria as compared with women with preeclampsia, where proteinuria has a more abrupt onset.

Spot Urine Protein-to-Creatinine Ratio to Predict the Magnitude of 24-Hour Total Proteinuria in Preeclampsia of Varying Severity

OBJECTIVE

The predictive value of spot urine protein-to-creatinine ratio (PCR) for estimating total 24-hour proteinuria in severe preeclampsia is unclear. This study aimed to assess the diagnostic accuracy of spot urine PCR for ascertaining the magnitude of proteinuria in women with preeclampsia of varying severity.

METHODS

A total of 205 patients with prediagnosed preeclampsia were included in this prospective cohort study. Patients were allocated into one of the three groups categorized by severity of disease, as follows: gestational hypertension, group 1 (n = 41); preeclampsia, group 2 (n = 88); and severe preeclampsia, group 3 (n = 76). We assessed the spot urine PCRs to determine significant proteinuria and the magnitude of proteinuria in these groups.

RESULTS

The spot urine PCR was 0.53, with 81% sensitivity and 93% specificity to detect significant proteinuria. A significant correlation was found between PCR and 24-hour total proteinuria in group 1 (r = 0.473, P = 0.002). There were also significant correlations in group 2 (r = 0.814, P < 0.001) and group 3 (r = 0.912, P < 0.001). The established formula using spot urine PCR to estimate 24-hour total proteinuria in severe preeclampsia was Y = 832.02X + 378.74 mg (r² = 0.8304).

CONCLUSION

Although 24-hour urine collection remains a merely reliable test to determine the degree of total proteinuria, our findings suggest that it is likely to assess the magnitude of proteinuria by the spot urine PCR, especially in severe preeclampsia.

CLINICAL TRIAL REGISTRATION

www.clinicaltrials.govNCT01623791.

Hypertension: The role of biochemistry in the diagnosis and management

Hypertension is defined as a persistently elevated blood pressure ≥140/90mmHg. It is an important treatable risk factor for cardiovascular disease, with a high prevalence in the general population. The most common cause, essential hypertension, is a widespread disease - however, secondary hypertension is under investigated and under diagnosed. Collectively, hypertension is referred to as a "silent killer" - frequently it displays no overt symptomatology. It is a leading risk factor for death and disability globally, with >40% of persons aged over 25 having hypertension. A vast spectrum of conditions result in hypertension spanning essential through resistant, to patients with an overt endocrine cause. A significant number of patients with hypertension have multiple cardiovascular risk factors at the time of presentation. Both routine and specialised biochemical investigations are paramount for the evaluation of these patients and their subsequent management. Biochemical testing serves to identify those hypertensive individuals who are at higher risk on the basis of evidence of dysglycaemia, dyslipidaemia, renal impairment, or target organ damage and to exclude identifiable causes of hypertension. The main target of biochemical testing is the identification of patients with a specific and treatable aetiology of hypertension. Information gleaned from biochemical investigation is used to risk stratify patients and tailor the type and intensity of subsequent management and treatment. We review the approach to the biochemical investigation of patients presenting with hypertension and propose a diagnostic algorithm for work-up.

Feasibility of nephrinuria as a screening tool for the risk of pre-eclampsia: prospective observational study

OBJECTIVES

To investigate the possibility of nephrinuria as a screening tool for the risk of pre-eclampsia (PE).

DESIGN

Prospective observational study.

SETTING

A single university hospital. Changes in urinary nephrin:creatinine ratio (NCR, ng/mg) and protein:creatinine ratio (PCR, mg/mg) in pregnancy were determined. Significant proteinuria in pregnancy (SPIP) was defined as PCR>0.27. PE was diagnosed in women with both SPIP and hypertension.

PARTICIPANTS

89 pregnant women in whom neither hypertension nor SPIP was present at enrolment, providing 31, 125 and 93 random urine samples during first, second and third trimesters, respectively.

RESULTS

PE developed in 14 of the 89 women. NCR increased with increasing PCR in 14 women with PE (correlation coefficient, 0.862; p<0.0001). In contrast, NCR did not change significantly despite significant increases in PCR in 75 women with normotensive pregnancies defined as neither SPIP nor hypertension, indicating that there was little increase in nephrinuria over the physiological range of proteinuria in pregnancy. Relative risk of later development of PE among asymptomatic second and third trimester women with NCR (ng/mg) >122 (95th centile value for 75 women with normotensive pregnancies) was 5.93 (95% CI 2.59 to 13.6; 60% (6/10) vs 10% (8/79)) and 13.5 (95% CI 3.31 to 55.0; 75% (6/8) vs 5.5% (2/36)), respectively, compared with women with NCR≤122 at that time.

CONCLUSIONS

Nephrinuria was unlikely to increase in normal pregnancy. A certain NCR cut-off may efficiently differentiate women at higher risk of PE.

Managing pregnancy in chronic kidney disease: improving outcomes for mother and baby

Parenthood is a central focus for women with chronic kidney disease, but raises important fears and uncertainties about risks to their own and their baby’s health. Pregnancy in women with background kidney disease, women receiving dialysis, or those with a functioning kidney transplant poses a challenging clinical scenario, associated with high maternal–fetal morbidity and potential impact on maternal renal health. Improvements in care over recent decades have led to a paradigm shift with cautious optimism and growing interest regarding pregnancies in women with chronic kidney disease. In this review, we discuss obstetric and renal outcomes, and practical aspects of management of pregnancy in this complex cohort.