First versus second trimester mean platelet volume and uric acid for prediction of preeclampsia in women at moderate and low risk

Clinical value of mean platelet volume in predicting and diagnosing pre-eclampsia: a systematic review and meta-analysis

Background

Pre-eclampsia (PE) is a severe pregnancy complication. Thrombocytopenia and platelet dysfunction are common hematology disorders in PE. Previous studies considered mean platelet volume (MPV), a functional marker of platelets, as a potentially useful predictor for the diagnosis of PE.

Methods

PubMed, China Biomedical Literature Database, Chinese National Knowledge Infrastructure, Embase, Wanfang, VIP, and Cochrane Library databases were searched to gather diagnostic trials evaluating the diagnosis of PE using MPV, from their inception to 13 March 2023. We also searched Google Scholar and Baidu.

Results

A total of 22 studies from 20 articles were found. The pooled diagnostic accuracy of the MPV for PE recognition was as follows: sensitivity (SEN) 0.676 [95% confidence interval (CI) (0.658-0.694)], specificity (SPE) 0.710 [95% CI (0.703-0.717)], and diagnostic odds ratio (DOR) 7.012 [95% CI (4.226-11.636)], and the SROC-AUC and Q* indices were 0.7889 and 0.7262, respectively. The pooled SEN, SPE, and DOR of the diagnostic accuracy of MPV for PE before 16 weeks of gestation were 0.707 [95% CI (0.670-0.743)], 0.639 [95% CI (0.611-0.667)], and 4.026 [95% CI (2.727-5.943)], and the SROC-AUC and Q* indices were 0.7278 and 0.6753, respectively. For the interval of truncation values between 9 and 10 fl, the SROC-AUC and Q* indices for MPV were 0.8856 and 0.8162, respectively.

Conclusions

Available evidence suggests that MPV has a moderate predictive and diagnostic value for PE, particularly in diagnosing after 20 weeks of gestation. The diagnostic accuracy is higher when the MPV cut-off falls between 9 and 10 fl. The sensitivity of MPV alone in diagnosing PE is not high, and the combination of other markers for predictive diagnosis may better differentiate PE.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023425154, identifier: CRD42023425154.

Incremental predictive value of platelet parameters for preeclampsia: results from a large prospective cohort study

BACKGROUND

Platelet parameters during pregnancy were associated with the risk of preeclampsia (PE), but the predictive value of these parameters for PE remained unclear. Our aim was to clarify the individual and incremental predictive value of platelet parameters, including platelet count (PC), mean platelet volume (MPV), plateletcrit (PCT), and platelet distribution width (PDW) for PE.

METHODS

This study was based on the Born in Guangzhou Cohort Study in China. Data on platelet parameters were extracted from medical records of routine prenatal examinations. Receiver operating characteristic (ROC) curve was performed to analyze the predictive ability of platelet parameters for PE. Maternal characteristic factors proposed by NICE and ACOG were used to develop the base model. Detection rate (DR), integrated discrimination improvement (IDI) and continuous net reclassification improvement (NRI) were calculated compared with the base model to assess the incremental predictive value of platelet parameters.

RESULTS

A total of 30,401 pregnancies were included in this study, of which 376 (1.24%) were diagnosed with PE. Higher levels of PC and PCT were observed at 12-19 gestational weeks in women who developed PE later. However, no platelet parameters before 20 weeks of gestation reliably distinguished between PE complicated pregnancy and non-PE complicated pregnancy, with all values of the areas under the ROC curves (AUC) below 0.70. The addition of platelet parameters at 16-19 gestational weeks to the base model increased the DR for preterm PE from 22.9 to 31.4% at a fixed false positive rate of 5%, improved the AUC from 0.775 to 0.849 (p = 0.015), and yielded a NRI of 0.793 (p < 0.001), and an IDI of 0.0069 (p = 0.035). Less but significant improvement in prediction performance was also observed for term PE and total PE when all the four platelet parameters were added to the base model.

CONCLUSIONS

Although no single platelet parameter at the early stage of pregnancy identified PE with high accuracy, the addition of platelet parameters to known independent risk factors could improve the prediction of PE.

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

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

Preeclampsia has an association with both platelet count and mean platelet volume: A systematic review and meta-analysis

Background

Preeclampsia (PE) is a pregnancy-specific disorder characterized by endothelial dysfunction, and activation of the coagulation system. Alteration of PLT parameters is the common hematological abnormality observed in women with PE. The main aim of this study was to systematically review previous studies from around the world to generate evidence about the relationship between platelet count (PC) and PE, as well as mean platelet volume (MPV) and PE, by calculating the pooled weighted mean difference (WMD) of PC and MPV between PE and normotensive (NT) groups.

Methods

Relevant articles which were published in the English language from January 10, 2011, to January 10, 2021, were systematically searched through PubMed, Web of Science, and African journals online. In addition, reference probing of published articles searching was employed through Google Scholar and Google for searching grey literature. The methodological qualities of articles were assessed using Joana Brigg’s institute critical appraisal checklist. A random-effects model was used to estimate pooled WMD of PLT parameters between the two groups with the respective 95% confidence intervals (CI) using Stata version 11.0. The I2 statistics and Egger’s regression test were used to assess heterogeneity and publication bias among included studies, respectively.

Results

A total of 25 articles were included in this systematic review and meta-analysis. Of which, 23 studies were used in each PC and MPV analysis. The overall pooled WMD of PC and MPV between PE and NT groups were -41.45 × 109/L [95% CI; -51.8, -31.0] and 0.98 fl [95% CI; 0.8, 1.1], respectively. The pooled WMD revealed that PC decreased significantly in the PE group compared to the NT group while MPV increased significantly in the PE group.

Conclusions

This systematic review and meta-analysis indicated that there is a significant decrease in PC and a significant increase in MPV during PE development among pregnant women. As a result, a change in these parameters among pregnant women may indicate the development of PE.

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.

Platelet Parameters and Risk of Hypertension disorders of Pregnancy: a Propensity Score Adjusted Analysis

While the role of platelets in cardiovascular diseases among the general population has been widely reported, evidence is inconsistent regarding the association between platelet indices with hypertension in pregnant women. In this study, we explored the associations between platelet parameters before 20 gestational weeks, an understudied period, with hypertensive disorders of pregnancy (HDP), including preeclampsia/eclampsia (PEEC) and gestational hypertension (GH). Based on the Born in Guangzhou Cohort Study, 12053 singleton pregnant women with platelet parameters, including platelet count (PC), mean platelet volume (MPV), plateletcrit (PCT), and platelet distribution width (PDW) measured at 14-19 gestational weeks were included. Conventional multivariable adjustment and propensity score analysis were used to control for confounders. The restricted cubic spline showed that the risk of PEEC increased linearly for PC, and non-linearly for PCT. For GH, the risk increased linearly for PC, MPV, and PCT, and non-linearly for PDW. When these indices were categorized into quintiles, women with higher PC and PCT were associated with increased risk of both PEEC and GH. Women with MPV exceeding the second quintile (≥ 8.8 fL) had a greater risk for GH, but not for PEEC. When HDP was classified into two groups (early- vs late-onset) based on the occurrence time, significant associations persisted for early-onset PEEC, early-onset GH, and late-onset GH. In conclusion, increased PC and PCT before 20 weeks of gestation were both associated with higher risk of PEEC and GH, while elevated MPV was only linked to GH.

Can complete blood count parameters that change according to trimester in pregnancy be used to predict severe preeclampsia?

We aimed to evaluate the effectiveness of changes over time in complete blood count (CBC) parameters to estimate the diagnosis of preeclampsia. Data on 161 severe preeclampsia patients and 161 healthy pregnant patients who met the study criteria of pregnant women whose CBC had been measured at 10-12, 22-24 and 28-30 weeks of pregnancy were compared. In the preeclampsia group, an increase in the mean platelet volume (MPV) value and a decrease in the number of platelets were statistically significant in the transition from the second to the third trimester. MPV and lymphocyte counts were more significant in the third trimester and neutrophil lymphocyte ratio (NLR) were more significant in the second trimester. We found that evaluation of the changes in lymphocyte, MPV and NLR values in three different trimesters of pregnancy rather than a single trimester was more meaningful to predict severe preeclampsia.Impact StatementWhat is already known on this subject? Studies have shown that MPV and NLR can predict preeclampsia. However, a clear cut off value could not be determined. The reasons for this may be that the gestational week during which the measurement is made is not standard and the patient groups are not homogeneous.What the results of this study add? In this study, CBC parameters at different stages of the preeclampsia process were compared in the severe preeclampsia group. According to our results, lymphocytes, NLR and MPV can be used to predict severe preeclampsia. In addition, NLR measurements in the second trimester and MPV and lymphocyte measurements in the third trimester were found to be more significant in predicting severe preeclampsia.What the implications are of these findings for clinical practice and/or further research? In order to predict severe preeclampsia, instead of a single measurement of CBC parameters, new calculations should be made that add change over time.

Predictive values of various serum biomarkers in women with suspected preeclampsia: A prospective study

BACKGROUND

Preeclampsia (PE) prediction has been shown to improve the maternal and fetal outcomes in pregnancy. We aimed to evaluate the PE prediction values of a series of serum biomarkers.

METHODS

The singleton pregnant women (20-36 gestational weeks) with PE-related clinical and/or laboratory presentations were recruited and had the blood drawn at their first visits. The following markers were tested with the collected serum samples: soluble fms-like tyrosine kinase 1 (sFlt-1), placental growth factor (PlGF), thrombomodulin (TM), tissue plasminogen activator inhibitor complex (tPAI-C), complement factors C1q, B, H, glycosylated fibronectin (GlyFn), pregnancy-associated plasma protein-A2 (PAPP-A2), blood urea nitrogen (BUN), creatinine (Cre), uric acid (UA), and cystatin C (Cysc).

RESULTS

Of the 196 recruited subjects, 25% (n = 49) developed preeclampsia before delivery, and 75% remained preeclampsia negative (n = 147). The serum levels of sFlt-1, BUN, Cre, UA, Cysc, and PAPP-A2 were significantly elevated, and the PlGF level was significantly decreased in the preeclampsia-positive patients. In the receiver operating characteristics (ROC) analyses, the area under the curves were listed in the order of decreasing values: 0.73 (UA), 0.67 (sFlt-1/PlGF), 0.66 (Cysc), 0.65 (GlyFn/PlGF), 0.64 (PAPP-A2/PlGF), 0.63 (BUN), 0.63 (Cre), and 0.60 (PAPP-A2). The positive predictive values of these serum markers were between 33.1% and 58.5%, and the negative predictive values were between 80.9% and 89.5%.

CONCLUSIONS

The serum markers investigated in current study showed better performance in ruling out than ruling in PE. Absence of pre-defined latency period between blood draw and the onset of PE limits the clinical utility of these markers.

Placenta-specific plasma miR518b is a potential biomarker for preeclampsia

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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