Development of pre-eclampsia within 4 weeks of sFlt-1/PlGF ratio > 38: comparison of performance at 31-34 vs 35-37 weeks' gestation

Administration of Antenatal Corticosteroids: Optimal Timing

The effectiveness of antenatal corticosteroids (ACS) in significantly reducing respiratory distress syndrome (RDS) depends crucially on the timing. It is successful if delivery takes place between 24 hours and seven days following administration; after this period, the side effects seem to predominate. In addition, an increased rate of mental impairment and behavioral disorders are observed in children born full-term after ACS administration. The optimal timing of ACS administration depends crucially on the given indication; to date, it has been achieved in only 25-40% of cases. ACS administration is always indicated in PPROM, in severe early pre-eclampsia, in fetal IUGR with zero or reverse flow in the umbilical artery, in placenta previa with bleeding, and in patients experiencing premature labor with a cervical length < 15 mm. The risk of women with asymptomatic cervical insufficiency giving birth within seven days is very low. In this case, ACS should not be administered even if the patient's cervical length is less than 15 mm, provided that the cervix is closed and there are no other risk factors for a premature birth. The development of further diagnostic methods with improved power to predict premature birth is urgently needed in order to optimize the timing of ACS administration in this patient population. Caution when administering ACS is also indicated in women experiencing premature labor who have a cervical length ≥ 15 mm. Further studies using amniocentesis are needed in order to identify the patient population with microbial invasion of the amniotic cavity/intra-amniotic infection (MIAC/IAI), and to define threshold values at which delivery is indicated. ACS administration is not performed as an emergency measure, usually not even before transfer to a perinatal center. Therefore, whenever possible, the indication for ACS administration should be determined by a clinician who is highly experienced in perinatology.

Comparison of the Soluble fms-Like Tyrosine Kinase 1/Placental Growth Factor Ratio Alone versus a Multi-Marker Regression Model for the Prediction of Preeclampsia-Related Adverse Outcomes after 34 Weeks of Gestation

INTRODUCTION

The objective of this retrospective study was to compare the predictive performance of the soluble fms-like tyrosine kinase 1 (sFlt-1)/placental growth factor (PlGF) ratio alone or in a multi-marker regression model for preeclampsia-related maternal and/or fetal adverse outcomes in women >34 weeks of gestation.

METHODS

We analyzed the data collected from 655 women with suspected preeclampsia. Adverse outcomes were predicted by multivariable and univariable logistic regression models. The outcome of patients was evaluated within 14 days after presentation with signs and symptoms of preeclampsia or diagnosed preeclampsia.

RESULTS

The full model integrating available, standard clinical information and the sFlt-1/PlGF ratio had the best predictive performance for adverse outcomes with an AUC of 72.6%, which corresponds to a sensitivity of 73.3% and specificity of 66.0%. The positive predictive value of the full model was 51.4%, and the negative predictive value was 83.5%. 24.5% of patients, who did not experience adverse outcomes but were classified as high risk by sFlt-1/PlGF ratio (≥38), were correctly classified by the regression model. The sFlt-1/PlGF ratio alone had a significantly lower AUC of 65.6%.

CONCLUSIONS

Integrating angiogenic biomarkers in a regression model improved the prediction of preeclampsia-related adverse outcomes in women at risk after 34 weeks of gestation.

One-third of patients with eclampsia at term do not have an abnormal angiogenic profile

OBJECTIVES

An abnormal angiogenic profile is present in about one-half of women with preeclampsia at term. Few studies examined the roles of angiogenic biomarkers in eclampsia. The aims of this study were to determine (1) whether the degree of an anti-angiogenic state, reflected by a low placental growth factor (PlGF) to soluble fms-like tyrosine kinase-1 (sFlt-1) ratio, in women with eclampsia differed from that of women with severe preeclampsia; and (2) the prevalence of women who had an abnormal angiogenic profile at the diagnoses of preterm and term eclampsia.

METHODS

A cross-sectional study was conducted to include women in the following groups: (1) uncomplicated pregnancy (n=40); (2) severe preeclampsia (n=50); and (3) eclampsia (n=35). Maternal serum concentrations of PlGF and sFlt-1 were determined by immunoassays.

RESULTS

Women with preterm, but not term, eclampsia had a more severe anti-angiogenic state than those with severe preeclampsia (lower PlGF and PlGF/sFlt-1 ratio, each p<0.05). However, the difference diminished in magnitude with increasing gestational age (interaction, p=0.005). An abnormal angiogenic profile was present in 95% (19/20) of women with preterm eclampsia but in only 67% (10/15) of women with eclampsia at term.

CONCLUSIONS

Angiogenic biomarkers can be used for risk assessment of preterm eclampsia. By contrast, a normal profile of angiogenic biomarkers cannot reliably exclude patients at risk for eclampsia at term. This observation has major clinical implications given that angiogenic biomarkers are frequently used in the triage area as a test to rule out preeclampsia.

Value of soluble fms-like tyrosine kinase-1/placental growth factor test in third trimester of pregnancy for predicting preeclampsia in asymptomatic women

OBJECTIVES

To estimate the value of screening maternal serum soluble fms-like tyrosine kinase/placental growth factor (sFlt-1/PlGF) ratio in asymptomatic women during 3rd trimester to predict preeclampsia (PE) development.

METHODS

The investigated group comprised of 178 pregnant women. During this gestation, 24 cases had developed PE and 12 isolated gestational hypertension (GH); whereas 142 remained normotensive. Blood samples were collected between 180 and 259 gestational days (g.d.) when the participants were asymptomatic. Serums were analyzed using the BRAHMS sFlt-1 Kryptor/BRAHMS PlGF plus Kryptor PE ratio test (Thermo Fisher Scientific, Henningdorf, Germany). High-risk pregnancies for the PE development were defined as sFlt-1/PlGF>38.

RESULTS

The detection rate (DR) for manifestation of PE≤30 days after sampling was 83.3% and overall DR during pregnancy 58.3%. Ten of 15 women having false positive prediction of PE suffered from GH, preterm birth and/or delivery of a small-for-gestational-age-newborn. False positive rate was significantly higher at 239-253 g.d. compared to sampling at 210-224 g.d. and 225-238 g.d. (21.9% vs. 7.8% and 5.3%; p < 0.05).

CONCLUSIONS

The sFlt-1/PlGF test during 180-259 g.d. detected approximately half of subsequent PE cases. An optimal time to use the test for screening purposes was estimated 225-238 g.d. (DR 66.7%). False positive test results were more common to cases with other adverse pregnancy outcomes and samples drawn at higher gestational age.

Comparison of ophthalmic artery Doppler with PlGF and sFlt-1/PlGF ratio at 35-37 weeks' gestation in prediction of imminent pre-eclampsia

OBJECTIVE

To compare the predictive performance for delivery with pre-eclampsia (PE) at < 3 weeks and at any stage after assessment at 35 + 0 to 36 + 6 weeks' gestation of serum placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1)/PlGF ratio with that of a competing-risks model utilizing maternal risk factors, mean arterial pressure (MAP) and ophthalmic artery peak systolic velocity (PSV) ratio.

METHODS

This was a prospective observational study of women attending for a routine hospital visit at 35 + 0 to 36 + 6 weeks' gestation. This visit included recording of maternal demographic characteristics and medical history, ultrasound examination of fetal anatomy and growth, assessment of flow velocity waveforms from the maternal ophthalmic arteries and measurement of MAP, serum PlGF and serum sFlt-1. The performance of screening for delivery with PE at < 3 weeks and at any time after the examination was assessed using areas under the receiver-operating-characteristics curves and detection rates (DRs), at a 10% false-positive rate (FPR). McNemar's test was used to compare DRs, at a 10% FPR, between screening by PlGF concentration, the sFlt-1/PlGF concentration ratio and the competing-risks model utilizing maternal risk factors, MAP and ophthalmic artery PSV ratio. Model-based estimates of screening performance for different methods of screening were also produced.

RESULTS

The study population of 2338 pregnancies contained 75 (3.2%) cases that developed PE, including 30 (1.3%) that delivered with PE at < 3 weeks from assessment, and 2263 cases unaffected by PE. The DR of PE at < 3 weeks from assessment, at a 10% FPR, of sFlt-1/PlGF ratio (70.0% (95% CI, 50.6-85.3%)) was superior to that of PlGF (50.0% (95% CI, 31.3-68.7%)) or PSV ratio (56.7% (95% CI, 37.4-74.5%)) but inferior to that of the combination of maternal risk factors, MAP multiples of the median (MoM) and PSV ratio delta (96.7% (95% CI, 82.8-99.9%)). Similarly, the DR of PE at any stage after assessment of sFlt-1/PlGF ratio (62.7% (95% CI, 50.7-73.6%)) was superior to that of PlGF (52.0% (95% CI, 40.2-63.7%)) or PSV ratio (41.3% (95% CI, 30.1-53.3%)) but inferior to that of the combination of maternal risk factors, MAP MoM and PSV ratio delta (78.7% (95% CI, 67.7-87.3%)). The empirical results for DR at a 10% FPR were consistent with the modeled results, both for delivery with PE at < 3 weeks and at any time after assessment.

CONCLUSION

Ophthalmic artery Doppler in combination with maternal risk factors and blood pressure could potentially replace measurement of PlGF and sFlt-1/PlGF ratio in the prediction of imminent PE. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

The diagnostic value of angiogenic and antiangiogenic factors in differential diagnosis of preeclampsia

The definition of preeclampsia is changing. However, with the addition of organ symptoms to the presence of hypertension in pregnancy instead of relying only on proteinuria, a more precise detection of women at risk of preeclampsia-associated adverse events has not been achieved. Instead, under the new definitions of the American College of Obstetricians and Gynecologists and of the International Society for the Study of Hypertension in Pregnancy, more women are classified as preeclamptic, with a tendency to milder disease. Furthermore, angiogenic and antiangiogenic factors have emerged as essential tools for predicting and diagnosing preeclampsia at high accuracies. Next to being rooted in the pathophysiology of the disease, they have been proven to be reliable tools for predicting and diagnosing the disease. In addition, 2 cutoffs have been evaluated for the clinical setting. As shown in the Prediction of Short-Term Outcome in Pregnant Women With Suspected Preeclampsia Study, at the soluble fms-like tyrosine kinase-1-to-placental growth factor ratio cutoff of 38, a preeclampsia can be ruled out for 1 week with a negative predictive value of 99.3% (95% confidence interval, 97.9-99.9) and ruled in with a positive predictive value of 36.7% (95% confidence interval, 28.4-45.7). The diagnostic cutoff of 85 has been shown to accurately identify women with preeclampsia, with a sensitivity of up to 88% and a specificity of 99.5%. In this review, we highlight the central role of angiogenic and antiangiogenic factors in the differential diagnosis of women presenting at high risk of the disease, such as patients with chronic hypertension or chronic kidney disease. We will focus on their ability to predict preeclampsia-associated adverse fetal and maternal outcomes. This is only possible when critically reviewing the evolution of the definition of "preeclampsia." We show how changes in this definition shape our clinical picture of the condition and how angiogenic and antiangiogenic biomarkers might be included to better identify women destined to develop preeclampsia-related adverse outcomes.

Clinical interpretation and implementation of the sFlt-1/PlGF ratio in the prediction, diagnosis and management of preeclampsia

Preeclampsia is associated with significant morbidity and mortality for mother and baby. Although around 30% of all pregnancies are evaluated for preeclampsia, diagnosis is difficult, especially in patients who have overlying symptoms from other diseases. Discovery of circulating angiogenic factors in the pathogenesis of preeclampsia has been a major advance for both diagnosis and prognosis. The anti-angiogenic factor, soluble fms-like tyrosine kinase 1 (sFlt-1) and the pro-angiogenic factor, placental growth factor (PlGF), can be measured in plasma and serum and are usually reported as a ratio, which specifically relates to the onset and severity of preeclampsia. The sFlt-1/PlGF ratio has a very high negative predictive value in ruling out the development of preeclampsia within 7 days among women with suspected preeclampsia. Currently, there is no clear consensus on the practical use of angiogenic biomarkers in the detection and management of preeclampsia in routine clinical practice. While major international clinical guidelines exist, they do not define which specific parameters signal patient admission, or outpatient evaluation of suspected preeclampsia, and most clinicians follow local practices. Better guidance is needed on risk stratification among women with suspected preeclampsia, as well as among women at high risk for preeclampsia. Prediction of adverse outcomes in women, after the clinical diagnosis of preeclampsia, is also important. This report has been developed following a meeting of international experts and aims to guide clinicians in the management of pregnant women at risk of preeclampsia using the sFlt-1/PlGF ratio test.

Maternal Serum Inhibin-A Augments the Value of Maternal Serum PlGF and of sFlt-1/PlGF Ratio in the Prediction of Preeclampsia and/or FGR Near Delivery—A Secondary Analysis

Objective: We previously provided evidence to confirm that maternal serum levels of soluble Fms-like tyrosine kinase-1 (sFlt-1), placental growth factor (PlGF), and their ratio are useful tools to direct the management of preeclampsia (PE), fetal growth restriction (FGR), and PE+FGR near delivery. In this secondary analysis, we further examine the potential additive value of maternal serum Inhibin-A, which is a hormone marker of the transforming growth factor family, to the accuracy provided by maternal serum PlGF and sFlt-1. Methods: We conducted a secondary analysis where we extracted the data of a cohort of 125 pregnant women enrolled near delivery at the clinics of the University Medical Center of Ljubljana, Slovenia. The dataset included 31 cases of PE, 16 of FGR, 42 of PE+FGR, 15 preterm delivery (PTD), and 21 unaffected controls with delivery of a healthy baby at term. Cases delivered before 34 weeks’ gestation included 10 of PE, 12 of FGR, 28 of PE+FGR, and 6 of PTD. In addition to the recorded demographic characteristics and medical history and the maternal serum levels of PlGF and sFlt-1/PlGF ratio, which were previously published, we evaluated the added value of maternal serum Inhibin-A. The predictive accuracy of each biomarker, their ratios, and combinations were estimated from areas under the curve (AUC) of receiver operating characteristics (ROC) curves, Box and Whisker plots, and by multiple regression. We estimated accuracy by the continuous marker model and a cutoff model. Results: In this study, we combined Inhibin-A with PlGF or with the sFlt-1/PlGF ratio and showed a 10–20% increase in AUCs and 15–45% increase in the detection rate, at 10% false positive rate, of PE, and a lower, but significant, increase for PE+FGR and FGR in all cases but not for FGR in early cases delivered < 34 weeks. The use of a cutoff model was adequate, although a bit higher accuracy was obtained from the continuous model. The highest correlation was found for PlGF with all three complications. Conclusion: In this secondary analysis, we have found that maternal serum Inhibin-A improves the accuracy of predicting PE and PE+FGR provided by maternal serum angiogenic markers alone, bringing the results to a diagnostic level; thus, it could be considered for directing clinical management. Inhibin-A had smaller or no added value for the accuracy of predicting FGR alone, mainly of early cases delivered <34 weeks.

Prediction of Preeclampsia-Related Adverse Outcomes With the sFlt-1 (Soluble fms-Like Tyrosine Kinase 1)/PlGF (Placental Growth Factor)-Ratio in the Clinical Routine: A Real-World Study

This retrospective real-world study investigated the clinical use of the sFlt-1 (soluble fms-like tyrosine kinase 1)/PlGF (placental growth factor) ratio alone or in combination with other clinical tests to predict an adverse maternal (maternal death, kidney failure, hemolysis elevated liver enzymes low platelets-syndrome, pulmonary edema, disseminated intravascular coagulation, cerebral hemorrhage, or eclampsia) or fetal (delivery before 34 weeks because of preeclampsia and/or intrauterine growth restriction, respiratory distress syndrome, necrotizing enterocolitis, intraventricular hemorrhage, placental abruption or intrauterine fetal death or neonatal death within 7 days post natum) pregnancy outcome in patients with signs and symptoms of preeclampsia. We evaluated the sFlt-1/PlGF-ratio cutoff values of 38 and 85 and evaluated its integration into a multimarker model. Of 1117 subjects, 322 (28.8%) developed an adverse fetal or maternal outcome. Patients with an adverse versus no adverse outcome had a median sFlt-1/PlGF-ratio of 177 (interquartile range, 54-362) versus 14 (4-64). Risk-stratification with the sFlt-1/PlGF cutoff values into high- (>85), intermediate- (38-85), and low-risk (<38) showed a significantly shorter time to delivery in high- and intermediate- versus low-risk patients (4 versus 8 versus 29 days). When integrating all available clinical information into a multimarker model, an area under the curve of 88.7% corresponding to a sensitivity, specificity, positive and negative predictive value of 80.0%, 87.3%, 75.0%, and 90.2% was reached. The sFlt-1/PlGF-ratio alone was inferior to the full model with an area under the curve of 85.7%. As expected, blood pressure and proteinuria were significantly less accurate with an area under the curve of 69.0%. Combining biomarker measurements with all available information in a multimarker modeling approach increased detection of adverse outcomes in women with suspected disease.

Single-Tube Multimarker Assay for Estimating the Risk to Develop Preeclampsia

BACKGROUND

Preeclampsia (PE) affects 2%-8% of all pregnancies worldwide. The predictive value of the currently used maternal serum fms-like tyrosine kinase-1/ placental growth factor (sFlt-1/PlGF) test is < 40% for PE onset within 4 weeks. We aimed to develop an innovative multiplex assay to improve PE prediction.

METHODS

The 6PLEX assay combining the measurements of ADAM12, sENG, leptin, PlGF, sFlt-1, and PTX3 was developed for the Luminex® xMAP platform. Assay performance was evaluated using 61 serum samples drawn from 53 pregnant women between 180 and 275 gestational days: diagnosed PE cases, n = 4; cases with PE onset within 4-62 days after sampling, n = 25; controls, n = 32. The B·R·A·H·M·S Kryptor sFlt-1/PlGF test (Thermo Fisher Scientific, Hennigsdorf, Germany) was applied as an external reference. Alternative PE prediction formulae combining 6PLEX measurements with clinical parameters were developed.

RESULTS

There was a high correlation in sFlt-1/PlGF estimated for individual sera between the 6PLEX and B·R·A·H·M·S Kryptor immunoassays (Spearman's r = 0.93, P < 0.0001). The predictive power of the 6PLEX combined with gestational age and maternal weight at sampling reached AUC 0.99 (95% CI 0.97-1.00) with sensitivity 100.0% and specificity 96.9%. In all models, sFlt-1/PlGF derived from the B·R·A·H·M·S immunoassays exhibited the lowest AUC value (<0.87) and sensitivity (<80%) with broad confidence intervals (13%-92%). The estimated prognostic yield of the 6PLEX compared to the B·R·A·H·M·S assay was significantly higher (96.5% vs 73.7%; P = 0.0005).

CONCLUSIONS

The developed single-tube multimarker assay for PE risk estimation in combination with clinical symptoms reached high prognostic yield (96.5%) and exhibited superior performance compared to the sFlt-1/PlGF test.

The competing risk approach for prediction of preeclampsia

The established method of the assessment of the risk for development of preeclampsia is to identify risk factors from maternal demographic characteristics and medical history; in the presence of such factors, the patient is classified as high risk and in their absence as low risk. Although this approach is simple to perform, it has poor performance of the prediction of preeclampsia and does not provide patient-specific risks. This review describes a new approach that allows the estimation of patient-specific risks of delivery with preeclampsia before any specified gestational age by maternal demographic characteristics and medical history with biomarkers obtained either individually or in combination at any stage in pregnancy. In the competing risks approach, every woman has a personalized distribution of gestational age at delivery with preeclampsia; whether she experiences preeclampsia or not before a specified gestational age depends on competition between delivery before or after the development of preeclampsia. The personalized distribution comes from the application of Bayes theorem to combine a previous distribution, which is determined from maternal factors, with likelihoods from biomarkers. As new data become available, what were posterior probabilities take the role as the previous probability, and data collected at different stages are combined by repeating the application of Bayes theorem to form a new posterior at each stage, which allows for dynamic prediction of preeclampsia. The competing risk model can be used for precision medicine and risk stratification at different stages of pregnancy. In the first trimester, the model has been applied to identify a high-risk group that would benefit from preventative therapeutic interventions. In the second trimester, the model has been used to stratify the population into high-, intermediate-, and low-risk groups in need of different intensities of subsequent monitoring, thereby minimizing unexpected adverse perinatal events. The competing risks model can also be used in surveillance of women presenting to specialist clinics with signs or symptoms of hypertensive disorders; combination of maternal factors and biomarkers provide patient-specific risks for preeclampsia that lead to personalized stratification of the intensity of monitoring, with risks updated on each visit on the basis of biomarker measurements.

Prediction of imminent preeclampsia at 35-37 weeks gestation

BACKGROUND

In the weeks preceding the clinical onset of preeclampsia, the maternal serum level of the angiogenic placental growth factor is decreased and that of the antiangiogenic factor soluble fms-like tyrosine kinase-1 is increased. Women presenting at specialist clinics with signs or symptoms of hypertensive disorders have been stratified according to concentrations of placental growth factor or the ratio of concentrations of soluble fms-like tyrosine kinase-1 and placental growth factor to determine clinical management for the subsequent 1-4 weeks. An alternative approach for the prediction of preeclampsia is use of the competing risks model, a Bayes' theorem based method, to derive patient-specific risk for preeclampsia by various combinations of maternal characteristics and medical history with multiples of the median values of biomarkers.

OBJECTIVE

The purpose of this study was to compare the performance of screening for delivery with preeclampsia at ≤2 and ≤4 weeks after assessment at 35⁺⁰-36⁺⁶ weeks gestation between the use of percentile cut-offs in placental growth factor alone or the soluble fms-like tyrosine kinase-1/placental growth factor ratio and the competing risks model.

STUDY DESIGN

This was a prospective observational study in women who attended a routine hospital visit at 35⁺⁰-36⁺⁶ weeks gestation in 2 maternity hospitals in England. The visits included the recording of maternal demographic characteristics and medical history and the measurement of serum placental growth factor and soluble fms-like tyrosine kinase-1 and mean arterial pressure. The areas under the receiver operating characteristics curves were used to compare the predictive performance for preeclampsia with delivery at ≤2 and ≤4 weeks from assessment of screening by placental growth factor alone and the soluble fms-like tyrosine kinase-1/placental growth factor ratio with that of a previously developed competing risks model with a combination of maternal factors, placental growth factor, soluble fms-like tyrosine kinase-1, and mean arterial pressure (triple test).

RESULTS

First, the study population of 15,247 pregnancies included 326 pregnancies (2.1%) that subsequently experienced preeclampsia. Second, in the screening for delivery with preeclampsia at ≤2 and ≤4 weeks from assessment, the performance of the triple test was superior to that of placental growth factor alone or the soluble fms-like tyrosine kinase-1/placental growth factor ratio. The area under the receiver operating characteristics curves for preeclampsia at ≤2 weeks in screening by the triple test (0.975; 95% confidence interval, 0.964-0.985) was higher than that of placental growth factor alone (0.900; 95% confidence interval, 0.866-0.935; P<.0001) and the soluble fms-like tyrosine kinase-1/placental growth factor ratio (0.932; 95% confidence interval, 0.904-0.960; P=.0001). Similarly, the areas under the receiver operating characteristics curves for preeclampsia at ≤4 weeks in screening by the triple test (0.907; 95% confidence interval, 0.886-0.928) was higher than that of placental growth factor alone (0.827; 95% confidence interval, 0.800-0.854; P<.0001) or the soluble fms-like tyrosine kinase-1/placental growth factor ratio (0.857; 95% confidence interval, 0.830-0.883; P<.0001). Third, at most, screen-positive rates of 2-30% the detection rate of delivery with preeclampsia at ≤2 and ≤4 weeks that was achieved by the triple test was approximately 10% higher than that of the soluble fms-like tyrosine kinase-1/placental growth factor ratio and 20% higher than that of placental growth factor alone; the negative predictive value was similar for the 3 tests.

CONCLUSION

At 35⁺⁰-36⁺⁶ weeks gestation, the performance of screening for imminent delivery with preeclampsia by the competing risks model is superior to that of placental growth factor alone or the soluble fms-like tyrosine kinase-1/placental growth factor ratio.

Efficacy of resveratrol to supplement oral nifedipine treatment in pregnancy-induced preeclampsia

OBJECTIVE

Preeclampsia (PE) is a complication affecting pregnant women worldwide, which usually manifests as severe maternal hypertension. Resveratrol (RESV), a naturally existing polyphenol, is known to exhibit beneficial effects in cardiovascular disease including hypertension. We evaluated the outcome of treatment combining oral nifedipine (NIFE) and RESV against PE.

DESIGN AND METHODS

Using a randomized group assignment, 400 PE patients were enrolled and received oral treatments of either NIFE + RESV or NIFE + placebo. Primary endpoints were defined as time to control blood pressure and time before a new hypertensive crisis. Secondary endpoints were defined as the number of doses needed to control blood pressure, maternal and neonatal adverse effects.

RESULTS

Compared with the NIFE + placebo group, the time needed to control blood pressure was significantly reduced in NIFE + RESV group, while time before a new hypertensive crisis was greatly delayed in NIFE + RESV group. The number of treatment doses needed to control blood pressure was also categorically lower in NIFE + RESV group. No differences in maternal or neonatal adverse effects were observed between the two treatment groups.

CONCLUSION

Our data support the potential of RESV as a safe and effective adjuvant of oral NIFE to attenuate hypertensive symptoms among PE patients.

The maternal plasma proteome changes as a function of gestational age in normal pregnancy: a longitudinal study

OBJECTIVE

Pregnancy is accompanied by dramatic physiological changes in maternal plasma proteins. Characterization of the maternal plasma proteome in normal pregnancy is an essential step for understanding changes to predict pregnancy outcome. The objective of this study was to describe maternal plasma proteins that change in abundance with advancing gestational age and determine biological processes that are perturbed in normal pregnancy.

STUDY DESIGN

A longitudinal study included 43 normal pregnancies that had a term delivery of an infant who was appropriate for gestational age without maternal or neonatal complications. For each pregnancy, 3 to 6 maternal plasma samples (median, 5) were profiled to measure the abundance of 1125 proteins using multiplex assays. Linear mixed-effects models with polynomial splines were used to model protein abundance as a function of gestational age, and the significance of the association was inferred via likelihood ratio tests. Proteins considered to be significantly changed were defined as having the following: (1) >1.5-fold change between 8 and 40 weeks of gestation; and (2) a false discovery rate-adjusted value of P < .1. Gene ontology enrichment analysis was used to identify biological processes overrepresented among the proteins that changed with advancing gestation.

RESULTS

The following results were found: (1) Ten percent (112 of 1125) of the profiled proteins changed in abundance as a function of gestational age; (2) of the 1125 proteins analyzed, glypican-3, sialic acid-binding immunoglobulin-type lectin-6, placental growth factor, C-C motif-28, carbonic anhydrase 6, prolactin, interleukin-1 receptor 4, dual-specificity mitogen-activated protein kinase 4, and pregnancy-associated plasma protein-A had more than a 5-fold change in abundance across gestation (these 9 proteins are known to be involved in a wide range of both physiological and pathological processes, such as growth regulation, embryogenesis, angiogenesis immunoregulation, inflammation etc); and (3) biological processes associated with protein changes in normal pregnancy included defense response, defense response to bacteria, proteolysis, and leukocyte migration (false discovery rate, 10%).

CONCLUSION

The plasma proteome of normal pregnancy demonstrates dramatic changes in both the magnitude of changes and the fraction of the proteins involved. Such information is important to understand the physiology of pregnancy and the development of biomarkers to differentiate normal vs abnormal pregnancy and determine the response to interventions.

Ratio of matrix metalloproteinase-2 to -9 is a more accurate predictive biomarker in women with suspected pre-eclampsia

Pre-eclampsia (PE) is a condition unique to pregnancy, and abnormal expression of matrix metalloproteinases (MMPs) has been implicated in its pathogenesis. We aimed to evaluate the reliability of plasma levels of MMP-2, MMP-9 and their relative ratio in predicting PE. A total of 318 women with suspected PE were recruited for the study, who were subsequently either cleared or diagnosed of PE and grouped accordingly. Their baseline characteristics were compared. Blood samples were also collected from all participants, to determine the plasma levels of MMP-2 and MMP-9. The predictive values of levels of MMP-2 and MMP-9, as well as their ratio, were analyzed using the receiver operating characteristic (ROC) curve. Either MMP-2 or MMP-9 alone did not exhibit any obvious differences between normal and PE pregnancies. However the ratio of MMP-2/MMP-9 was significantly higher in PE-affected pregnancy than normal control group. ROC curve analysis also indicated that the MMP-2/MMP-9 ratio provided better compromise between specificity and sensitivity in distinguishing PE from normal pregnancies, than either of the two MMPs alone. MMP-2/MMP-9 ratio is a more accurate biomarker to predict PE than either MMP-2 or MMP-9 alone.