Diagnostic accuracy of placental growth factor in women with suspected preeclampsia: a prospective multicenter study.

BACKGROUND: Hypertensive disorders of pregnancy are a major contributor to death and disability for pregnant women and their infants. The diagnosis of preeclampsia by using blood pressure and proteinuria is of limited use because they are tertiary, downstream features of the disease. Placental growth factor (PlGF) is an angiogenic factor, a secondary marker of associated placental dysfunction in preeclampsia, with known low plasma concentrations in the disease. METHODS AND RESULTS: In a prospective multicenter study, we studied the diagnostic accuracy of low plasma PlGF concentration (<5th centile for gestation, Alere Triage assay) in women presenting with suspected preeclampsia between 20 and 35 weeks' gestation (and up to 41 weeks' gestation as a secondary analysis). The outcome was delivery for confirmed preeclampsia within 14 days. Of 625 women, 346 (55%) developed confirmed preeclampsia. In 287 women enrolled before 35 weeks' gestation, PlGF <5th centile had high sensitivity (0.96; 95% confidence interval, 0.89-0.99) and negative predictive value (0.98; 0.93-0.995) for preeclampsia within 14 days; specificity was lower (0.55; 0.48-0.61). Area under the receiver operating characteristic curve for low PlGF (0.87, standard error 0.03) for predicting preeclampsia within 14 days was greater than all other commonly used tests, singly or in combination (range, 0.58-0.76), in women presenting with suspected preeclampsia (P<0.001 for all comparisons). CONCLUSIONS: In women presenting before 35 weeks' gestation with suspected preeclampsia, low PlGF has high sensitivity and negative predictive value for preeclampsia within 14 days, is better than other currently used tests, and presents an innovative adjunct to management of such women.

Placental Growth Factor (PlGF) in Women with Suspected Pre-Eclampsia Prior to 35 Weeks' Gestation: A Budget Impact Analysis.

OBJECTIVE: To model the resource implications of placental growth factor (PlGF) testing in women with suspected pre-eclampsia prior to 35 weeks' gestation as part of a management algorithm, compared with current practice. METHODS: Data on resource use from 132 women with suspected pre-eclampsia prior to 35 weeks' gestation, enrolled in a prospective observational cohort study evaluating PlGF measurement within antenatal assessment units within two UK consultant-led maternity units was extracted by case note review. A decision analytic model was developed using these data to establish the budget impact of managing women with suspected pre-eclampsia for two weeks from the date of PlGF testing, using a clinical management algorithm and reference cost tariffs. The main outcome measures of resource use (numbers of outpatient appointments, ultrasound investigations and hospital admissions) were correlated to final diagnosis and used to calculate comparative management regimes. RESULTS: The mean cost saving associated with the PlGF test (in the PlGF plus management arm) was £35,087 (95% CI -£33,181 to -£36,992) per 1,000 women. This equated to a saving of £582 (95% CI -552 to -£613) per woman tested. In 94% of iterations, PlGF testing was associated with cost saving compared to current practice. CONCLUSIONS: This analysis suggests PlGF used as part of a clinical management algorithm in women presenting with suspected pre-eclampsia prior to 35 weeks' gestation could provide cost savings by reducing unnecessary resource use. Introduction of PlGF testing could be used to direct appropriate resource allocation and overall would be cost saving.

Diagnostic Biomarkers in Women With Suspected Preeclampsia in a Prospective Multicenter Study.

OBJECTIVE: To evaluate 47 biomarkers (selected from the current medical literature), in isolation or in combination with placental growth factor (PlGF), to determine the need for delivery within 14 days, in women presenting with suspected preterm preeclampsia. METHODS: In a prospective, multicenter observational study, 47 biomarkers were measured in 423 women presenting with suspected preterm preeclampsia (in two prespecified groups: group 1 at less than 35 weeks of gestation and group 2 presenting between 35 0/7 and 36 6/7 weeks of gestation) to evaluate their ability to determine the primary endpoint: preeclampsia requiring delivery within 14 days. Using factor analysis and stepwise logistic regression, we sought one or more additional biomarkers for optimal determination of the primary endpoint. RESULTS: In women presenting at less than 35 weeks of gestation (n=286), the best performing combination of PlGF, podocalyxin, endoglin, procalcitonin (receiver operating curve [ROC] area 0.90, 95% confidence interval [CI] 0.86-0.93) was not statistically better than PlGF alone (ROC 0.87, 95% CI 0.83-0.92; P=.43) for preeclampsia requiring delivery within 14 days. Two other single markers had test performance that was not significantly different to PlGF (soluble fms-like tyrosine kinase-1 [sFlt-1] ROC 0.83, 95% CI 0.78-0.88; endoglin ROC 0.83, 95% CI 0.79-0.88). Similar findings were found in women presenting between 35 0/7 and 36 6/7 weeks of gestation (n=137): ROC for PlGF alone 0.75 (95% CI 0.67-0.83); ROC for PlGF, cystatin, pregnancy-associated plasma protein A in combination 0.81 (95% CI 0.74-0.88; P=.40). CONCLUSION: This study supports the growing body of evidence that a single angiogenesis-related biomarker (PlGF, sFlt-1, or endoglin) alone represents a useful diagnostic test for women presenting with suspected preterm preeclampsia.

PP051. Budget impact analysis of maternal plasma PIGF concentrations in women with suspected pre-eclampsia: The potential for improved health service usage.

INTRODUCTION: Existing methods of assessing women with suspected pre-eclampsia are expensive and labour intensive, yet perform poorly. OBJECTIVES AND METHODS: The PELICAN multi-centre observational cohort study demonstrated that PlGF predicts need for delivery for pre-eclampsia within 14 days. We constructed a decision analytical model using outcome data from 100 women comparing resource use by final diagnosis and PlGF level. Costs were obtained from 2012-2013 NHS tariffs. RESULTS: Of the 100 women, 40 had a final diagnosis of pre-eclampsia and delivered within 14 days of the PlGF test; 10 were healthy pregnancies with normal PlGF levels. 82% of women with pre-eclampsia were admitted during the final 2 weeks of pregnancy, with a 5-day (SD=5) length of stay, compared with 30% of healthy pregnancies with normal PlGF (1 day; SD=0.58). Resource use for outpatient appointments, scans and day unit admissions was similar for the two groups although higher in the group with a final diagnosis of pre-eclampsia. Total costs, excluding delivery, were approximately a third higher in the pre-eclampsia group. CONCLUSIONS: This interim analysis suggests pre-eclampsia is associated with significantly higher resource use, although there is some inappropriate resource use in healthy women. PlGF can assist diagnosis and identify women requiring increased care and could be used to direct appropriate resource allocation in women over 37 weeks.

Use of vitamin C and E to prevent preeclampsia.

A review of the evidence exploring the effects of vitamin supplementation on pre-eclampsia and its co-morbidities.