Placental Growth Factor informed management of suspected pre-eclampsia or fetal growth restriction: The MAPPLE cohort study

The role of the PLGF in the prediction of the outcome in pregnancies with a small for gestational age fetus

PURPOSE

To explore the value of measuring maternal serum PLGF in the prediction of the outcome of small for gestational age fetuses (SGA).

METHODS

Singleton pregnancies referred with suspicion of SGA in the third trimester were included if they had: no indication for nor signs of imminent delivery, fetal abdominal circumference (AC) at or below the 10th centile and/or estimated fetal weight (EFW) at or below the 10th centile and/or umbilical artery pulsatility index (Umb-PI) at or above the 90th centile for gestation. Women with pre-eclampsia at presentation were excluded. Maternal blood was drawn at the first (index) visit and analyzed retrospectively.

RESULTS

Fifty-one fetuses were examined. Multiple regression analysis showed that family history of microsomia, index EFW and PLGF were significant predictors of the birthweight centile; index femur length centile and PLGF were significant predictors of pre-eclampsia; PLGF and index systolic blood pressure were significant predictors of iatrogenic preterm delivery < 37 weeks, whereas PLGF and index EFW were significant predictors of birthweight ≤ 5th centile and admission to the neonatal intensive care unit. For all outcomes, the addition of maternal-fetal parameters did not improve the prediction compared to PLGF alone. Using a cutoff of 0.3 MoM for PLGF would identify 94.1% of the pregnancies with iatrogenic preterm delivery and/or intra-uterine death and all of the cases that developed pre-eclampsia, for a screen positive rate of 54.9%. Women with PLGF ≤ 0.3 MoM had a poor fetal/maternal outcome (iatrogenic preterm delivery, pre-eclampsia, intra-uterine death) in 61.5% of cases.

CONCLUSION

In pregnancies complicated by SGA, PLGF identifies a very high-risk group that may benefit from intense surveillance.

Maternal Serum Angiogenic Profile and Its Correlations with Ultrasound Parameters and Perinatal Results in Normotensive and Preeclamptic Pregnancies Complicated by Fetal Growth Restriction

FGR is a complication of pregnancy in which the fetus does not reach its programmed growth potential due to placental reasons and it is the single largest risk factor of stillbirth. Babies with FGR are at increased risk of mortality and morbidity not only in the perinatal period, but also in later life. FGR presents a huge challenge for obstetricians in terms of its detection and further monitoring of pregnancy. The ultrasound is the gold standard here; apart from assessing fetal weight, it is used to measure Doppler flows in maternal and fetal circulation. It seems that additional tests, like biochemical angiogenic factors measurement would be helpful in diagnosing FGR, identifying fetuses at risk and adjusting the surveillance model. The study aimed to assess the potential relationship between the concentration of sEng, sFlt-1, PlGF, and the sFlt-1/PlGF ratio in maternal serum at delivery and maternal and fetal Doppler flow measurements as well as perinatal outcomes in pregnancies complicated by FGR with and without PE, isolated PE cases and normal pregnancies. The use of angiogenic markers is promising not only in PE but also in FGR. Numerous correlations between ultrasound and Doppler studies, perinatal outcomes and disordered angiogenesis marker levels in maternal serum suggest that biochemical parameters have a great potential to be used as a complementary method to diagnose and monitor pregnancies with FGR. The, PlGF in particular, could play an outstanding role in this regard.

Placental growth factor in assessment of women with suspected pre-eclampsia to reduce maternal morbidity: a stepped wedge cluster randomised control trial (PARROT Ireland)

OBJECTIVE

To determine whether the addition of placental growth factor (PlGF) measurement to current clinical assessment of women with suspected pre-eclampsia before 37 weeks' gestation would reduce maternal morbidity without increasing neonatal morbidity.

DESIGN

Stepped wedge cluster randomised control trial from 29 June 2017 to 26 April 2019.

SETTING

National multisite trial in seven maternity hospitals throughout the island of Ireland PARTICIPANTS: Women with a singleton pregnancy between 20⁺⁰ to 36⁺⁶ weeks' gestation, with signs or symptoms suggestive of evolving pre-eclampsia. Of the 5718 women screened, 2583 were eligible and 2313 elected to participate.

INTERVENTION

Participants were assigned randomly to either usual care or to usual care plus the addition of point-of-care PlGF testing based on the randomisation status of their maternity hospital at the time point of enrolment.

MAIN OUTCOMES MEASURES

Co-primary outcomes of composite maternal morbidity and composite neonatal morbidity. Analysis was on an individual participant level using mixed-effects Poisson regression adjusted for time effects (with robust standard errors) by intention-to-treat.

RESULTS

Of the 4000 anticipated recruitment target, 2313 eligible participants (57%) were enrolled, of whom 2219 (96%) were included in the primary analysis. Of these, 1202 (54%) participants were assigned to the usual care group, and 1017 (46%) were assigned the intervention of additional point-of-care PlGF testing. The results demonstrate that the integration of point-of-care PlGF testing resulted in no evidence of a difference in maternal morbidity-457/1202 (38%) of women in the control group versus 330/1017 (32%) of women in the intervention group (adjusted risk ratio (RR) 1.01 (95% CI 0.76 to 1.36), P=0.92)-or in neonatal morbidity-527/1202 (43%) of neonates in the control group versus 484/1017 (47%) in the intervention group (adjusted RR 1.03 (0.89 to 1.21), P=0.67).

CONCLUSIONS

This was a pragmatic evaluation of an interventional diagnostic test, conducted nationally across multiple sites. These results do not support the incorporation of PlGF testing into routine clinical investigations for women presenting with suspected preterm pre-eclampsia, but nor do they exclude its potential benefit.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02881073.

Use of the angiogenic biomarker profile to risk stratify patients with fetal growth restriction

BACKGROUND

Novel angiogenic biomarker profiles have demonstrated emerging evidence for predicting preeclampsia onset, severity, and adverse outcomes. Limited data exist in screening patients with fetal growth restriction for preeclampsia development using angiogenic biomarkers.

OBJECTIVE

The objective of this study was to risk stratify patients with fetal growth restriction using a soluble fms-like tyrosine kinase-1 to placental growth factor ratio. Previously published cutoff of 38 was used to predict preeclampsia development and severity as well as adverse maternal or neonatal outcomes within a 2-week time period.

STUDY DESIGN

This was a prospective observational cohort study performed in a single tertiary hospital. Patients with a singleton fetal growth restriction pregnancy between 24 and 37 weeks' gestation were evaluated using serial 2-week encounters from the time of enrollment to delivery. Pregnancies with proven genetic or infectious etiology of fetal growth restriction or congenital anomalies were excluded. Ultrasound growth and Doppler measurements were obtained at the start of every encounter with routine preeclampsia laboratory tests and blood pressure checks when clinically indicated. Maternal serum was collected for all serial encounters and measured for soluble fms-like tyrosine kinase-1 and placental growth factor after delivery in a double-blinded fashion. Maternal charts were reviewed for baseline demographic characteristics, pregnancy diagnoses and outcomes, and neonatal outcomes.

RESULTS

A total of 45 patients were enrolled for a total of 77 encounters, with the median (quartile 1, quartile 3) gestational age of the study enrolled at 31.43 (28.14-33.57) weeks. Patients were divided into low-risk (ratio of <38) and high-risk (ratio of ≥38) groups. Baseline characteristics of patients did not show any marked differences, including preeclampsia labs or ultrasound parameters, between the 2 groups. Systolic and diastolic blood pressures upon enrollment were statistically elevated when soluble fms-like tyrosine kinase-1 to placental growth factor ratio was ≥38 (P=.02 and P=.01, respectively). Compared to patients with a low ratio, patients with a high ratio had a greater proportion of preeclampsia diagnosis, higher rates of preterm delivery under 34 and 37 weeks gestation, smaller neonatal birthweight, and a shorter time to delivery from testing to delivery.

CONCLUSION

Among patients with fetal growth restriction, the soluble fms-like tyrosine kinase-1 to placental growth factor ratio may serve as a potential biomarker for identifying at risk patients for developing preeclampsia and subsequently preterm delivery.

PlGF (Placental Growth Factor) Testing in Clinical Practice: Evidence From a Canadian Tertiary Maternity Referral Center

[Figure: see text].

A comparative study of two immunoassays of maternal placental growth factor

Circulating maternal levels of placental growth factor correlates well with placental function and numerous studies advocate its role to help rule-out preterm pre-eclampsia. A number of automated immunoassay platforms to quantify placental growth factors are currently available. The aim of this study was to highlight the importance of developing and validating appropriate reference ranges and clinical cut-offs for immunoassays, by comparing the results obtained from two different immunoassays of placental growth factor; the Quantikine^® ELISA and the automated Triage^® test. This was a secondary subgroup analysis of samples collected as part of a prospective cross-sectional study of placental growth factors in twin pregnancy. Consenting pregnant women with a twin pregnancy, across a variety of gestations, had a single blood sample taken at a one-time point only during their pregnancy. The plasma was initially biobanked and then later analysed in batches using both immunoassays. Although the placental growth factor values of the two immunoassays correlated well (r = 0.88, n = 178, p < .001), the actual results obtained were significantly different (mean difference 238.1 pg/ml). Poor concordance between the two immunoassays was also present, with the Triage^® test recording 36 cases as <100 pg/ml whereas the Quantikine^® ELISA identified only 4 as <100 pg/ml. Biomarker levels may vary significantly between different immunoassay platforms, highlighting the importance of developing validated clinical cut-offs for any automated immunoassay before its clinical application. These differences need to be understood to facilitate clinical utility given that placental growth factor testing is likely to be introduced into widespread clinical practice.

Placental growth factor measurements in the assessment of women with suspected Preeclampsia: A stratified analysis of the PARROT trial

OBJECTIVE

Placental growth factor testing decreases time to recognition of preeclampsia and may reduce severe maternal adverse outcomes. This analysis aims to describe the clinical phenotype of women by PlGF concentration, and to determine the mechanism(s) underpinning the reduction in severe maternal adverse outcomes in the PARROT trial, in order to inform how PlGF testing may be optimally used within clinical management algorithms.

STUDY DESIGN

This was a planned secondary analysis from the PARROT trial that compared revealed PlGF testing and management guidance with usual care in the assessment of women with suspected preterm preeclampsia.

MAIN OUTCOME MEASURES

Maternal and perinatal outcomes following stratification of women by trial group, and measured PlGF concentration.

RESULTS

1006 women were included. PlGF < 100 pg/ml identified women with more marked hypertension, increased adverse maternal outcomes and preterm delivery rates, and higher rates of small for gestational age infants. There was a reduction in adverse maternal outcomes in women whose results were revealed when PlGF levels were 12-100 pg/ml compared to usual care (3.8% vs 6.9%; aOR 0.15(95% CI 0.03-0.92). There was no significant difference in gestation at delivery between concealed or revealed groups in any PlGF categories.

CONCLUSION

Low PlGF concentrations are associated with severe preeclampsia. The reduction in severe adverse maternal outcomes may be mediated through quicker diagnosis and intensive surveillance, as recommended by the management algorithm for those at increased risk. PlGF is particularly beneficial in those who test 12-100 pg/ml, as these may be women with silent multi-organ disease who otherwise may go undetected.

The PLANES study: a protocol for a randomised controlled feasibility study of the placental growth factor (PlGF) blood test-informed care versus standard care alone for women with a small for gestational age fetus at or after 32 + 0 weeks' gestation

Background

Stillbirth remains a major concern across the globe and in some high-resource countries, such as the UK; efforts to reduce the rate have achieved only modest reductions. One third of stillborn babies are small for gestational age (SGA), and these pregnancies are also at risk of neonatal adverse outcomes and lifelong health problems, especially when delivered preterm. Current UK clinical guidance advocates regular monitoring and early term delivery of the SGA fetus; however, the most appropriate regimen for surveillance of these babies remains unclear and often leads to increased intervention for a large number of these women. This pilot trial will determine the feasibility of a large-scale trial refining the risk of adverse pregnancy outcome in SGA pregnancies using biomarkers of placental function sFlt-1/PlGF, identifying and intervening in only those deemed at highest risk of stillbirth.

Methods

PLANES is a randomised controlled feasibility study of women with an SGA fetus that will be conducted at two tertiary care hospitals in the UK. Once identified on ultrasound, women will be randomised into two groups in a 3:1 ratio in favour of sFlt-1/PlGF ratio led management vs standard care. Women with an SGA fetus and a normal sFlt-1/PlGF ratio will have a repeat ultrasound and sFlt-1/PlGF ratio every 2 weeks with planned birth delayed until 40 weeks. In those women with an SGA fetus and an abnormal sFlt-1/PlGF ratio, we will offer birth from 37 weeks or sooner if there are other concerning features on ultrasound. Women assigned to standard care will have an sFlt-1/PlGF ratio taken, but the results will be concealed from the clinical team, and the woman’s pregnancy will be managed as per the local NHS hospital policy. This integrated mixed method study will also involve a health economic analysis and a perspective work package exploring trial feasibility through interviews and questionnaires with participants, their partners, and clinicians.

Discussion

Our aim is to determine feasibility through the assessment of our ability to recruit and retain participants to the study. Results from this pilot study will inform the design of a future large randomised controlled trial that will be adequately powered for adverse pregnancy outcome. Such a study would provide the evidence needed to guide future management of the SGA fetus.

Trial registration

ISRCTN58254381. Registered on 4 July 2019

Levels of serum Hoxb3 and sFlt-1 in pre-eclamptic patients and their effects on pregnancy outcomes

AIM

We aimed to explore a new approach and theoretical basis for the diagnosis, treatment and prognosis of pre-eclampsia.

METHODS

In total, 103 pre-eclamptic patients (study group: SG) and 100 healthy pregnant women (control group: CG) were enrolled. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression level of serum Hoxb3. Enzyme-linked immunosorbent assay was used to detect the content of serum sFlt-1. Pregnancy outcomes in the two groups were recorded, and the correlations of the levels of Hoxb3 and sFlt-1 with the pregnancy outcomes were analyzed.

RESULTS

The relative expression of serum Hoxb3 mRNA in the CG was significantly higher than that in the SG, whereas the content of serum sFlt-1 in the CG was significantly lower than that in the SG. Compared with the CG, the SG had a significantly lower number of spontaneous deliveries, higher number of cesarean deliveries and significantly higher number of uneventful perinatal births. The incidences of intrauterine growth restriction, intrauterine distress, premature infants and neonatal deaths in perinatal infants in the SG were significantly higher than those in the CG. According to the analysis of receiver operating characteristic curves, the areas under the curves of Hoxb3, sFlt-1 and their combined detection for diagnosing pre-eclampsia were 0.799, 0.856 and 0.930, respectively. The areas under the curves for predicting poor perinatal outcomes were 0.724, 0.828 and 0.871, respectively.

CONCLUSION

In conclusion, Hoxb3 and sFlt-1 have certain reference significance for the risk evaluation of pre-eclampsia and the adverse pregnancy outcomes of pre-eclampsia women.

Preeclampsia and the anaesthesiologist: current management

PURPOSE OF REVIEW

Preeclampsia remains an important cause of maternal and neonatal morbidity and mortality. Recent interest in angiogenic biomarkers as a prognostic indicator is reviewed, together with analgesic, anaesthetic and critical-care management of the preeclamptic patient.

RECENT FINDINGS

There has been recent interest in the angiogenic biomarkers placental growth factor and soluble fms-like tyrosine kinase-1 in establishing the diagnosis of preeclampsia and guiding its management. Neuraxial blocks are recommended for both labour and operative delivery if not contraindicated by thrombocytopenia or coagulopathy, although a safe lower limit for platelet numbers has not been established. For spinal hypotension phenylephrine is noninferior to ephedrine in preeclamptic parturients and may offer some benefits. When general anaesthesia is required, efforts must be made to blunt the hypertensive response to laryngoscopy and intubation. Transthoracic echocardiography has emerged as useful technique to monitor maternal haemodynamics in preeclampsia.

SUMMARY

Improvements in the diagnosis of preeclampsia may lead to better outcomes for mothers and babies. Peripartum care requires a multidisciplinary team approach with many preeclamptic women receiving neuraxial analgesia or anaesthesia. Women with severe preeclampsia may require critical-care support and this should meet the same standards afforded to other acutely unwell patients.

Stillbirth at term: Does size really matter?

Placental dysfunction has a deleterious influence on fetal size and is associated with higher rates of perinatal morbidity and mortality. This association underpins the strategy of fetal size evaluation as a mechanism to identify placental dysfunction and prevent stillbirth. The optimal method of routine detection of small for gestational age (SGA) remains to be clarified with choices between estimation of symphyseal-fundal height versus routine third-trimester ultrasound, various formulae for fetal weight estimation by ultrasound, and the variable use of national, customized, or international fetal growth references. In addition to these controversies, the strategy for detecting SGA is further undermined by data demonstrating that the relationship between fetal size and adverse outcome weakens significantly with advancing gestation such that near term, the majority of stillbirths and adverse perinatal outcomes occur in normally sized fetuses. The use of maternal serum biochemical and Doppler parameters near term appears to be superior to fetal size in the identification of fetuses compromised by placental dysfunction and at increased risk of damage or demise. Multiparameter models and predictive algorithms using maternal risk factors, and biochemical and Doppler parameters have been developed, but need to be prospectively validated to demonstrate their effectiveness.

Precision Diagnostics by Affinity-Mass Spectrometry: A Novel Approach for Fetal Growth Restriction Screening During Pregnancy

Fetal growth restriction (FGR) affects about 3% to 8% of pregnancies, leading to higher perinatal mortality and morbidity. Current strategies for detecting fetal growth impairment are based on ultrasound inspections. However, antenatal detection rates are insufficient and critical in countries with substandard care. To overcome difficulties with detection and to better discriminate between high risk FGR and low risk small for gestational age (SGA) fetuses, we investigated the suitability of risk assessment based on the analysis of a recently developed proteome profile derived from maternal serum in different study groups. Maternal serum, collected at around 31 weeks of gestation, was analyzed in 30 FGR, 15 SGA, and 30 control (CTRL) pregnant women who delivered between 31 and 40 weeks of gestation. From the 75 pregnant women of this study, 2 were excluded because of deficient raw data and 2 patients could not be grouped due to indeterminate results. Consistency between proteome profile and sonography results was obtained for 59 patients (26 true positive and 33 true negative). Of the proteome profiling 12 contrarious grouped individuals, 3 were false negative and 9 were false positive cases with respect to ultrasound data. Both true positive and false positive grouping transfer the respective patients to closer surveillance and thorough pregnancy management. Accuracy of the test is considered high with an area-under-curve value of 0.88 in receiver-operator-characteristics analysis. Proteome profiling by affinity-mass spectrometry during pregnancy provides a reliable method for risk assessment of impaired development in fetuses and consumes just minute volumes of maternal peripheral blood. In addition to clinical testing proteome profiling by affinity-mass spectrometry may improve risk assessment, referring pregnant women to specialists early, thereby improving perinatal outcomes.

Diagnostic accuracy of repeat placental growth factor measurements in women with suspected preeclampsia: A case series study

Introduction

Preeclampsia affects about 3% of singleton pregnancies and is characterized by placental dysfunction. It is associated with significant maternal and perinatal morbidity and mortality. The diagnosis of preeclampsia remains a challenge, and the clinical course can develop for weeks before a diagnosis is confirmed. National guidelines have approved placental growth factor (PlGF) testing to rule out suspected preeclampsia, but the utility of repeated PlGF measurement is unknown. The aim of this case series analysis was to evaluate the test performance of repeated PlGF sampling in women presenting with suspected preeclampsia, and to describe relevant clinical outcomes.

Material and methods

Women who presented to maternity services with suspected preeclampsia between 20⁺⁰ and 36⁺⁶ weeks’ gestation who underwent repeat PlGF sampling with a minimum test interval of 7 days were assessed. The outcomes were delivery for preeclampsia within 14 days of sampling, the proportion changing PlGF categories, and time to delivery.

Results

In total, 289 women with suspected preeclampsia undergoing repeat PlGF sampling were included. PlGF <100 pg/mL had a high sensitivity (87.5%, 95% confidence interval [CI] 67.6%‐97.3%) and a negative predictive value (97.7%, 95% CI 93.5%‐99.5%) at the initial test (receiver operating characteristic [ROC] area 0.79, 95% CI 0.68‐0.89). Similar test performance was seen for PlGF <100 pg/mL when undertaken as a repeat test (sensitivity 90.7%, 95% CI 85.2%‐95.9%, negative predictive value 92.2%, 95% CI 85.3‐96.6%). Overall, 25.6% of women changed PlGF category between the first and second PlGF tests. For each PlGF category, determination of time to delivery was similar for first and second tests.

Conclusions

Repeat PlGF measurement demonstrates high negative predictive value for determining preeclampsia requiring delivery in 14 days. Repeat testing may be clinically useful to risk stratify women with ongoing symptoms of disease. Confirmation of the impact of these findings is required in further studies.

Placental growth factor testing to assess women with suspected pre-eclampsia: a multicentre, pragmatic, stepped-wedge cluster-randomised controlled trial

BACKGROUND

Previous prospective cohort studies have shown that angiogenic factors have a high diagnostic accuracy in women with suspected pre-eclampsia, but we remain uncertain of the effectiveness of these tests in a real-world setting. We therefore aimed to determine whether knowledge of the circulating concentration of placental growth factor (PlGF), an angiogenic factor, integrated with a clinical management algorithm, decreased the time for clinicians to make a diagnosis in women with suspected pre-eclampsia, and whether this approach reduced subsequent maternal or perinatal adverse outcomes.

METHODS

We did a multicentre, pragmatic, stepped-wedge cluster-randomised controlled trial in 11 maternity units in the UK, which were each responsible for 3000-9000 deliveries per year. Women aged 18 years and older who presented with suspected pre-eclampsia between 20 weeks and 0 days of gestation and 36 weeks and 6 days of gestation, with a live, singleton fetus were invited to participate by the clinical research team. Suspected pre-eclampsia was defined as new-onset or worsening of existing hypertension, dipstick proteinuria, epigastric or right upper-quadrant pain, headache with visual disturbances, fetal growth restriction, or abnormal maternal blood tests that were suggestive of disease (such as thrombocytopenia or hepatic or renal dysfunction). Women were approached individually, they consented for study inclusion, and they were asked to give blood samples. We randomly allocated the maternity units, representing the clusters, to blocks. Blocks represented an intervention initiation time, which occurred at equally spaced 6-week intervals throughout the trial. At the start of the trial, all units had usual care (in which PlGF measurements were also taken but were concealed from clinicians and women). At the initiation time of each successive block, a site began to use the intervention (in which the circulating PlGF measurement was revealed and a clinical management algorithm was used). Enrolment of women continued for the duration of the blocks either to concealed PlGF testing, or after implementation, to revealed PlGF testing. The primary outcome was the time from presentation with suspected pre-eclampsia to documented pre-eclampsia in women enrolled in the trial who received a diagnosis of pre-eclampsia by their treating clinicians. This trial is registered with ISRCTN, number 16842031.

FINDINGS

Between June 13, 2016, and Oct 27, 2017, we enrolled and assessed 1035 women with suspected pre-eclampsia. 12 (1%) women were found to be ineligible. Of the 1023 eligible women, 576 (56%) women were assigned to the intervention (revealed testing) group, and 447 (44%) women were assigned to receive usual care with additional concealed testing (concealed testing group). Three (1%) women in the revealed testing group were lost to follow-up, so 573 (99%) women in this group were included in the analyses. One (<1%) woman in the concealed testing group withdrew consent to follow-up data collection, so 446 (>99%) women in this group were included in the analyses. The median time to pre-eclampsia diagnosis was 4·1 days with concealed testing versus 1·9 days with revealed testing (time ratio 0·36, 95% CI 0·15-0·87; p=0·027). Maternal severe adverse outcomes were reported in 24 (5%) of 447 women in the concealed testing group versus 22 (4%) of 573 women in the revealed testing group (adjusted odds ratio 0·32, 95% CI 0·11-0·96; p=0·043), but there was no evidence of a difference in perinatal adverse outcomes (15% vs 14%, 1·45, 0·73-2·90) or gestation at delivery (36·6 weeks vs 36·8 weeks; mean difference -0·52, 95% CI -0·63 to 0·73).

INTERPRETATION

We found that the availability of PlGF test results substantially reduced the time to clinical confirmation of pre-eclampsia. Where PlGF was implemented, we found a lower incidence of maternal adverse outcomes, consistent with adoption of targeted, enhanced surveillance, as recommended in the clinical management algorithm for clinicians. Adoption of PlGF testing in women with suspected pre-eclampsia is supported by the results of this study.

FUNDING

National Institute for Health Research.

PARROT Ireland: Placental growth factor in Assessment of women with suspected pre-eclampsia to reduce maternal morbidity: a Stepped Wedge Cluster Randomised Control Trial Research Study Protocol

INTRODUCTION

Women presenting with suspected pre-eclampsia are currently triaged on the basis of hypertension and dipstick proteinuria. This may result in significant false positive and negative diagnoses resulting in increased morbidity or unnecessary intervention. Recent data suggest that placental growth factor testing may be a useful adjunct in the management of women presenting with preterm pre-eclampsia. The primary objective of this trial is to determine if the addition of placental growth factor testing to the current clinical assessment of women with suspected preterm pre-eclampsia, is beneficial for both mothers and babies.

METHODS AND ANALYSIS

This is a multicentre, stepped wedge cluster, randomised trial aiming to recruit 4000 women presenting with symptoms suggestive of preterm pre-eclampsia between 20 and 36+6 weeks' gestation. The intervention of an unblinded point of care test, performed at enrolment, will quantify maternal levels of circulating plasma placental growth factor. The intervention will be rolled out sequentially, based on randomisation, in the seven largest maternity units on the island of Ireland. Primary outcome is a composite outcome of maternal morbidity (derived from the modified fullPIERS model). To ensure we are not reducing maternal morbidity at the expense of earlier delivery and worse neonatal outcomes, we have established a co-primary outcome which will examine the effect of the intervention on neonatal morbidity, assessed using a composite neonatal score. Secondary analyses will examine further clinical outcomes (such as mode of delivery, antenatal detection of growth restriction and use of antihypertensive agents) as well as a health economic analysis, of incorporation of placental growth factor testing into routine care.

ETHICS AND DISSEMINATION

Ethical approval has been granted from each of the seven maternity hospitals involved in the trial. The results of the trial will be presented both nationally and internationally at conference and published in an international peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT02881073.