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

Early pregnancy maternal blood pressure and risk of preeclampsia: Does the association differ by parity? Evidence from 14,086 women across 7 countries

OBJECTIVE

To determine if the relationship between blood pressure (BP) before 16 weeks' gestation and subsequent onset of preeclampsia differs by parity, and by history of hypertensive disorders of pregnancy (HDP) in parous women.

STUDY DESIGN

Data from two studies were pooled. First, routinely collected clinical data from three metropolitan hospitals in Sydney, Australia (2017-2020), where BP was measured as part of routine clinical care using validated mercury-free sphygmomanometers. Second, prospectively collected research data from the INTERBIO-21st Study, conducted in six countries, investigating the epidemiology of fetal growth restriction and preterm birth, where BP was measured by dedicated research staff using an automated machine validated for use in pregnancy.

MAIN OUTCOME

Adjusted odds ratios (aOR) (95% confidence interval (CI)) for the association of systolic BP (SBP), diastolic BP (DBP) and mean arterial pressure (MAP) with preeclampsia were obtained from logistic regression models. Models were adjusted for age, smoking, body mass index, previous hypertension, previous diabetes, and previous preeclampsia. Interactions for parity, and history of HDP in parous women were included.

RESULTS

There were 14,086 pregnancies (Sydney = 11008, INTERBIO-21st = 3078) in the pooled analyses, 6914 (49 %) were parous, of which 414 (6.0 %) had a history of HDP. Nulliparous women had a higher risk of preeclampsia (2.6 %) compared with parous women (1.5 %): [aOR (95 %CI) 3.61 (2.67, 4.94)], as did parous women with a history of HDP (15.0 %) compared with no history (0.7 %) [12.70 (8.02, 20.16)]. MAP before 16 weeks' gestation (mean [SD] 78.8[8.6] mmHg) was more strongly associated than SBP or DBP with development of preeclampsia in parous women [2.22 (1.81, 2.74)] per SD higher MAP] compared with nulliparous women [1.58 (1.34, 1.87)] (p for interaction 0.013). There were no significant differences on the effect of blood pressure on preeclampsia in parous women by history of HDP (p for interaction 0.5465).

CONCLUSION

The risk of preeclampsia differs according to parity and history of HDP in a previous pregnancy. Blood pressure in early pregnancy predicts preeclampsia in all groups, although more strongly associated in parous than nulliparous women, but no different in parous women by history of HDP.

sFlt1/PlGF among patients with suspected preeclampsia when considering hypertensive status

BACKGROUND

In high-resource settings, biomarkers of angiogenic balance, such as the soluble fms-like tyrosine kinase-1 (sFlt1)/placental growth factor (PlGF) ratio, have been studied extensively to aid in evaluation of patients with suspected preeclampsia (PE), and have been incorporated into the 2021 International Society for the Study of Hypertension in Pregnancy definition of PE. The utility in under-resourced settings has not been as well characterized.

OBJECTIVE

This analysis sought to identify the role of the sFlt1/PlGF ratio in the evaluation of patients with or without hypertension who are suspected of having PE without other diagnostic information.

STUDY DESIGN

This is a secondary analysis of a prior prospective study of patients who were presented with suspected PE at ≥20+0 weeks' gestation at a single academic tertiary care center. Patients were recruited in the parent study from July 2009 to June 2012. In the original study, clinicians were masked to biomarker results, and patients were followed by chart review. In this analysis, the performance of the sFlt1/PlGF ratio (≤38, >38, or >85) was assessed alone in identifying both hypertensive and non-hypertensive patients at risk of evolving into PE with severe features (PE-SF; American College of Obstetricians and Gynecologists' definition) within two weeks of the triage visit (PE-SF2). Hypertension was defined as a blood pressure (BP)≥140/90 mmHg.

RESULTS

There were 1043 patients included in the analysis; of whom, 579 (55.5%) and 464 (44.5%) presented with or without hypertension, respectively. In triage, 332 (75.4%) of hypertensive patients presented due to BP concerns, and the remainder were evaluated due to other features (new-onset headache, proteinuria, or edema). On triage evaluation, 66.8% of all patients had a normal sFlt1/PlGF ratio ≤38, and 17.0% had an elevated ratio >85. Among hypertensive patients, a sFlt1/PlGF ratio ≤38 was a good rule-out test for PE-SF2 (negative likelihood ratio [LR-] of 0.15), and a ratio >85 was a good rule-in test (positive likelihood ratio [LR+] of 5.75). Among normotensive patients, sFlt1/PlGF was useful as a rule-in test for ratio >38 (LR+ 5.13) and >85 (LR+ 12.80). Stratified by gestational age, sFlt1/PlGF continued to be a good rule in and good rule out test at <35 weeks among those with hypertension but did not have good test performance ≥35 weeks. sFlt1/PlGF had a good test performance as a rule in test for >85 regardless of gestational age. In triage, 4.3% (30/693) of patients with sFlt1/PlGF ratio <38 had concurrent laboratory evidence of PE, compared with 15.9% (28/176) patients with ratio >85.

CONCLUSION

These findings support the potential for the use of sFlt1/PlGF and BP measurement alone in resource-limited settings where other laboratory tests or clinical expertise are unavailable for risk stratification. Performance of the biomarker varied by the presence of hypertension and gestational age.

Prediction of preterm birth in growth-restricted and appropriate-for-gestational-age infants using maternal PlGF and the sFlt-1/PlGF ratio-A prospective study

OBJECTIVE

To assess the utility of placental growth factor (PlGF) levels and the soluble fms-like tyrosine kinase-1/placental growth factor (sFlt-1/PlGF) ratio to predict preterm birth (PTB) for infants with fetal growth restriction (FGR) and those appropriate for gestational age (AGA).

DESIGN

Prospective, observational cohort study.

SETTING

Tertiary maternity hospital in Australia.

POPULATION

There were 320 singleton pregnancies: 141 (44.1%) AGA, 83 (25.9%) early FGR (<32+0 weeks) and 109 (30.0%) late FGR (≥32+0 weeks).

METHODS

Maternal serum PlGF and sFlt-1/PlGF ratio were measured at 4-weekly intervals from recruitment to delivery. Low maternal PlGF levels and elevated sFlt-1/PlGF ratio were defined as <100 ng/L and >5.78 if <28 weeks and >38 if ≥28 weeks respectively. Cox proportional hazards models were used. The analysis period was defined as the time from the first measurement of PlGF and sFlt-1/PlGF ratio to the time of birth or censoring.

MAIN OUTCOME MEASURES

The primary study outcome was overall PTB. The relative risks (RR) of birth within 1, 2 and 3 weeks and for medically indicated and spontaneous PTB were also ascertained.

RESULTS

The early FGR cohort had lower median PlGF levels (54 versus 229 ng/L, p < 0.001) and higher median sFlt-1 levels (2774 ng/L versus 2096 ng/L, p < 0.001) and sFlt-1/PlGF ratio higher (35 versus 10, p < 0.001). Both PlGF <100 ng/L and elevated sFlt-1/PlGF ratio were strongly predictive for PTB as well as PTB within 1, 2 and 3 weeks of diagnosis. For both FGR and AGA groups, PlGF <100 ng/L or raised sFlt-1/PlGF ratio were strongly associated with increased risk for medically indicated PTB. The highest RR was seen in the FGR cohort when PlGF was <100 ng/L (RR 35.20, 95% CI 11.48-175.46).

CONCLUSIONS

Low maternal PlGF levels and elevated sFlt-1/PlGF ratio are potentially useful to predict PTB in both FGR and AGA pregnancies.

Repeat Placental Growth Factor-Based Testing in Women With Suspected Preterm Preeclampsia: A Stratified Analysis of the PARROT-2 Trial

BACKGROUND

PlGF (placental growth factor)-based testing reduces severe maternal adverse outcomes. Repeat PlGF-based testing is not associated with improved perinatal or maternal outcomes. This planned secondary analysis aimed to determine whether there is a subgroup of women who benefit from repeat testing.

METHODS

Pregnant individuals with suspected preterm preeclampsia were randomized to repeat revealed PlGF-based testing, compared with usual care where testing was concealed. Perinatal and maternal outcomes were stratified by trial group, by initial PlGF-based test result, and by PlGF-based test type (PlGF or sFlt-1 [soluble fms-like tyrosine kinase-1]/PlGF ratio).

RESULTS

A total of 1252 pregnant individuals were included. Abnormal initial PlGF-based test identified a more severe phenotype of preeclampsia, at increased risk of adverse maternal and perinatal outcomes. Repeat testing was not significantly associated with clinical benefit in women with abnormal initial results. Of women with a normal initial result, 20% developed preeclampsia, with the majority at least 3 to 4 weeks after initial presentation. Repeat test results were more likely to change from normal to abnormal in symptomatic women (112/415; 27%) compared with asymptomatic women (163/890; 18%). A higher proportion of symptomatic women who changed from normal to abnormal were diagnosed with preeclampsia, compared with asymptomatic women.

CONCLUSIONS

Our results do not demonstrate evidence of the clinical benefit of repeating PlGF-based testing if the initial result is abnormal. Judicious use of repeat PlGF-based testing to stratify risk may be considered at least 2 weeks after a normal initial test result, particularly in women who have symptoms or signs of preeclampsia.

REGISTRATION

URL: https://www.isrctn.com/ISRCTN85912420; Unique identifier: ISRCTN85912420.

Translation of mechanistic advances in preeclampsia to the clinic: Long and winding road

As one of the leading causes of premature birth and maternal and infant mortality worldwide, preeclampsia remains a major unmet public health challenge. Preeclampsia and related hypertensive disorders of pregnancy are estimated to cause >75 000 maternal and 500 000 infant deaths globally each year. Because of rising rates of risk factors such as obesity, in vitro fertilization and advanced maternal age, the incidence of preeclampsia is going up with rates ranging from 5% to 10% of all pregnancies worldwide. A major discovery in the field was the realization that the clinical phenotypes related to preeclampsia, such as hypertension, proteinuria, and other adverse maternal/fetal events, are due to excess circulating soluble fms-like tyrosine kinase-1 (sFlt-1, also referred to as sVEGFR-1). sFlt-1 is an endogenous anti-angiogenic protein that is made by the placenta and acts by neutralizing the pro-angiogenic proteins vascular endothelial growth factor (VEGF) and placental growth factor (PlGF). During the last decade, this work has spawned a new era of molecular diagnostics for early detection of this condition. Antagonizing sFlt-1 either by reducing production or blocking its actions has shown salutary effects in animal models. Further, in early-stage human studies, the therapeutic removal of sFlt-1 from maternal circulation has shown promise in delaying disease progression and improving outcomes. Recently, the FDA approved the first molecular test for preterm preeclampsia (sFlt-1/PlGF ratio) for clinical use in the United States. Measuring serum sFlt-1/PlGF ratio in the acute hospital setting may aid short-term management, particularly regarding step-up or step-down of care, decision to transfer to settings better equipped to manage both the mother and the preterm neonate, appropriate timing of administration of steroids and magnesium sulfate, and in expectant management decisions. The test itself has the potential to save lives. Furthermore, the availability of a molecular test that correlates with adverse outcomes has set the stage for interventional clinical trials testing treatments for this disorder. In this review, we will discuss the role of circulating sFlt-1 and related factors in the pathogenesis of preeclampsia and specifically how this discovery is leading to concrete advances in the care of women with preeclampsia.

[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.

Longitudinal assessment of angiogenic markers in prediction of adverse outcome in women with confirmed pre-eclampsia

OBJECTIVES

Angiogenic marker assessment, such as the ratio of soluble fms-like tyrosine kinase-1 (sFlt-1) to placental growth factor (PlGF), is known to be a useful tool in the prediction of pre-eclampsia (PE). However, evidence from surveillance strategies in pregnancies with a PE diagnosis is lacking. Therefore, we aimed to assess the predictive performance of longitudinal maternal serum angiogenic marker assessment for both maternal and perinatal adverse outcomes when compared to standard laboratory parameters in pregnancies with confirmed PE.

METHODS

This was a retrospective analysis of prospectively collected data from January 2013 to December 2020 at the Medical University of Vienna. The inclusion criteria were singleton pregnancy with confirmed PE and post-diagnosis maternal serum angiogenic marker assessment at a minimum of two timepoints. The primary outcome was the predictive performance of longitudinal sFlt-1 and PlGF assessment for adverse maternal and perinatal outcomes compared to conventional laboratory monitoring at the same time in pregnancies with confirmed PE. Composite adverse maternal outcome included intensive care unit admission, pulmonary edema, eclampsia and/or death. Composite adverse perinatal outcome included stillbirth, neonatal death, placental abruption, neonatal intensive care unit admission, intraventricular hemorrhage, necrotizing enterocolitis, respiratory distress syndrome and/or mechanical ventilator support.

RESULTS

In total, 885 post-diagnosis sFlt-1/PlGF ratio measurements were obtained from 323 pregnant women with confirmed PE. For composite adverse maternal outcome, the highest standalone predictive accuracy was obtained using maternal serum sFlt-1/PlGF ratio (area under the receiver-operating-characteristics curve (AUC), 0.72 (95% CI, 0.62-0.81)), creatinine (AUC, 0.71 (95% CI, 0.62-0.81)) and lactate dehydrogenase (LDH) levels (AUC, 0.73 (95% CI, 0.65-0.81)). Maternal platelet levels (AUC, 0.65 (95% CI, 0.55-0.74)), serum alanine aminotransferase (ALT) (AUC, 0.59 (95% CI, 0.49-0.69)) and aspartate aminotransferase (AST) (AUC, 0.61 (95% CI, 0.51-0.71) levels had poor standalone predictive accuracy. The best prediction model consisted of a combination of maternal serum LDH, creatinine levels and sFlt-1/PlGF ratio, which had an AUC of 0.77 (95% CI, 0.68-0.85), significantly higher than sFlt-1/PlGF ratio alone (P = 0.037). For composite adverse perinatal outcome, the highest standalone predictive accuracy was obtained using maternal serum sFlt-1/PlGF ratio (AUC, 0.82 (95% CI, 0.75-0.89)) and creatinine (AUC, 0.74 (95% CI, 0.67-0.80)) levels, sFlt-1/PlGF ratio being superior to creatinine alone (P < 0.001). Maternal serum LDH levels (AUC, 0.65 (95% CI, 0.53-0.74)), platelet count (AUC, 0.57 (95% CI, 0.44-0.67)), ALT (AUC, 0.58 (95% CI, 0.48-0.67)) and AST (AUC, 0.58 (95% CI, 0.48-0.67)) levels had poor standalone predictive accuracy. No combination of biomarkers was superior to maternal serum sFlt-1/PlGF ratio alone for prediction of composite adverse perinatal outcome (P > 0.05 for all).

CONCLUSIONS

In pregnancies with confirmed PE, longitudinal maternal serum angiogenic marker assessment is a good predictor of adverse maternal and perinatal outcomes and superior to some conventional laboratory parameters. Further studies should focus on optimal surveillance following diagnosis of PE. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Advances in preeclampsia testing

Preeclampsia is a multisystem hypertensive disorder and one of the leading causes of maternal and fetal morbidity and mortality. The clinical hallmarks such as hypertension and proteinuria, and additional laboratory tests currently available including liver enzyme testing, are neither specific nor sufficiently sensitive. Therefore, biomarkers for timely and accurate identification of patients at risk of developing preeclampsia are extremely valuable to improve patient outcomes and safety. In this chapter, we will first discuss the clinical characteristics of preeclampsia and current evidence of the role of angiogenic factors, such as placental growth factor (PlGF) and soluble FMS like tyrosine kinase 1 (sFlt-1) in the pathogenesis of preeclampsia. Second, we will review the clinical practice guidelines for preeclampsia diagnostic criteria and their recommendations on laboratory testing. Third, we will review the currently available PlGF and sFlt-1 assays in terms of their methodologies, analytical performance, and clinical diagnostic values. Finally, we will discuss the future research needs from both an analytical and clinical perspective.

Placental Growth Factor (PlGF)- Based Biomarker Testing to Help Diagnose Pre-eclampsia in People With Suspected Pre-eclampsia: A Health Technology Assessment

Background

Pre-eclampsia is a potentially serious condition affecting up to 5% of pregnancies, most frequently after 20 weeks' gestation. Placental growth factor (PlGF)-based tests measure either the blood level of PlGF or the ratio of soluble fms-like tyrosine kinase-1 (sFlt-1) to PlGF. They are intended to complement standard clinical assessment to help diagnose pre-eclampsia in people with suspected pre-eclampsia. We conducted a health technology assessment of PlGF-based biomarker testing as an adjunct to standard clinical assessment to help diagnose pre-eclampsia in pregnant people with suspected pre-eclampsia, which included an evaluation of diagnostic accuracy, clinical utility, cost-effectiveness, the budget impact of publicly funding PlGF-based biomarker testing, and an assessment of preferences and values.

Methods

We performed a systematic literature search of the clinical evidence. We assessed the risk of bias of each included study using AMSTAR 2, Cochrane Risk of Bias tool, the Quality of Diagnostic Accuracy Studies 2 (QUADAS-2) tool, and the quality of the body of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. We performed a systematic literature search of the economic evidence. We did not conduct a primary economic evaluation as the impact of the test on maternal and neonatal outcomes is uncertain. We also analyzed the budget impact of publicly funding PlGF-based biomarker testing in pregnant people with suspected pre-eclampsia in Ontario. To contextualize the potential value of PlGF-based biomarker testing, we spoke with people whose pregnancies had been impacted by pre-eclampsia as well as their family members.

Results

We included one systematic review and one diagnostic accuracy study in the clinical evidence review. The Elecsys sFlt-1/PlGF ratio test using a test cut-off of less than 38 for ruling out pre-eclampsia within 1 week yielded a negative predictive value (NPV) of 99.2% and the DELFIA Xpress PlGF 1-2-3 test using a cut-off of 150 pg/mL or greater for ruling out pre-eclampsia within 1 week yielded a NPV of 94.8% (diagnostic GRADE: Moderate for both tests). All clinical utility outcomes were associated with uncertainties (GRADE: Low).We included 13 studies in the economic evidence review, most of which concluded that the use of PlGF-based biomarker testing resulted in cost savings. Seven studies were partially applicable to the Ontario health care setting but have some important limitations; the remaining 6 studies were not applicable. We estimated that publicly funding PlGF-based biomarker testing for people with suspected pre-eclampsia in Ontario would lead to an additional annual cost of $0.27 million in year 1 to $0.46 million in year 5, for a total additional cost of $1.83 million over 5 years.Direct engagement included 24 people who had been impacted by pre-eclampsia during their pregnancies as well as one family member. Participants described the emotional and physical impacts of having suspected pre-eclampsia and subsequent treatments. Those that we spoke with valued shared decision-making and identified potential gaps in patient education, specifically as it relates to symptom management for suspected pre-eclampsia. Overall, the participants viewed PlGF-based biomarker testing positively for its perceived medical benefits and minimal invasiveness. They felt that access to PlGF-based biomarker testing may also improve health outcomes through improved patient education, care coordination, and patient-centred care (e.g., prompting more frequent prenatal monitoring, when needed). In addition, PlGF-based biomarker testing was perceived to be equally beneficial for family members who may act as the health care proxy in an emergency. Lastly, participants emphasized that there should be equitable access to PlGF-based biomarker testing and support from a care provider should be offered when trying to interpret the results, particularly if the results are accessible through an online patient portal.

Conclusions

Compared with standard clinical assessment alone in people with suspected pre-eclampsia (gestational age between 20 and 36 weeks + 6 days), PlGF-based biomarker testing as an adjunct to standard clinical assessment likely improves prediction of pre-eclampsia. It may also reduce time to pre-eclampsia diagnosis, severe adverse maternal outcomes, and length of stay in the neonatal intensive care unit, although the evidence is uncertain. PlGF-based biomarker testing may result in little to no difference in other clinical outcomes such as maternal admission to hospital and perinatal adverse outcomes.The economic literature review showed that PlGF-based biomarker testing was cost-effective for use in people with suspected pre-eclampsia, but with some uncertainties. A primary economic evaluation was not done for this health technology assessment because the impact of the test on maternal and neonatal outcomes is uncertain. Publicly funding PlGF-based biomarker testing for people with suspected pre-eclampsia would lead to an additional cost of $1.83 million over 5 years.Publicly funding PlGF-based biomarker testing was viewed favourably by people directly impacted by pre-eclampsia as well as their family members. Those with whom we spoke valued testing to help diagnose suspected pre-eclampsia and valued the potential medical benefits. Participants emphasized that patient education, and equitable access to PlGF-based biomarker testing should be requirements for implementation in Ontario.

Novel therapeutic and diagnostic approaches for preeclampsia

PURPOSE OF REVIEW

This review will summarize recent findings relating to the diagnostic approach to preeclampsia and current avenues of research aimed at modifying the underlying disease process.

RECENT FINDINGS

Growing international consensus supports a broad preeclampsia definition that incorporates maternal end-organ and uteroplacental dysfunction. Recent evidence demonstrates that this definition better identifies women and babies at risk of adverse outcomes compared to the traditional definition of hypertension and proteinuria. Multiple studies have demonstrated the usefulness and cost-effectiveness of angiogenic biomarkers such as soluble fms-like tyrosine kinase-1 and placental growth factor as a clinical adjunct to diagnose and predict severity of preeclampsia associated outcomes. Current novel therapeutic approaches to preeclampsia target pathogenic pathways (e.g. antiangiogenesis) or downstream effects such as oxidative stress and nitric oxide. Recent findings relating to these promising candidates are discussed. Multicenter clinical trials are needed to evaluate their effectiveness and ability to improve fetal and maternal outcomes.

SUMMARY

We provide an updated framework of the current approaches to define and diagnose preeclampsia. Disease modifying therapies (in particular, targeting the angiogenic pathway) are being developed for the first time and promise to revolutionize the way we manage preeclampsia.

Prediction of perinatal survival in early-onset fetal growth restriction: role of placental growth factor

OBJECTIVE

To analyze the ability to predict perinatal survival and severe neonatal morbidity of cases with early-onset fetal growth restriction (eoFGR) using maternal variables, ultrasound parameters and angiogenic markers at the time of diagnosis.

METHODS

This was a prospective observational study in a cohort of singleton pregnancies with a diagnosis of eoFGR (< 32 weeks of gestation). At diagnosis of eoFGR, complete assessment was performed, including ultrasound examination (anatomy, biometry and Doppler assessment) and maternal serum measurement of the angiogenic biomarkers, soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF). Logistic regression models for the prediction of perinatal survival (in cases diagnosed at < 28 weeks) and severe neonatal morbidity (in all liveborn cases) were calculated.

RESULTS

In total, 210 eoFGR cases were included, of which 185 (88.1%) survived perinatally. The median gestational age at diagnosis was 27 + 0 weeks. All cases diagnosed at ≥ 28 weeks survived. In cases diagnosed < 28 weeks, survivors (vs non-survivors) had a higher gestational age (26.1 vs 24.4 weeks), estimated fetal weight (EFW; 626 vs 384 g), cerebroplacental ratio (1.1 vs 0.9), PlGF (41 vs 18 pg/mL) and PlGF multiples of the median (MoM; 0.10 vs 0.06) and lower sFlt-1/PlGF ratio (129 vs 479) at the time of diagnosis (all P < 0.001). The best combination of two variables for predicting perinatal survival was provided by EFW and PlGF MoM (area under the receiver-operating-characteristics curve (AUC), 0.84 (95% CI, 0.75-0.92)). These were also the best variables for predicting severe neonatal morbidity (AUC, 0.73 (95% CI, 0.66-0.80)).

CONCLUSIONS

A model combining EFW and maternal serum PlGF predicts accurately perinatal survival in eoFGR cases diagnosed before 28 weeks of gestation. Prenatal prediction of severe neonatal morbidity in eoFGR cases is modest regardless of the model used. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Practical guide for the management of hypertensive disorders during pregnancy

Hypertensive disorders of pregnancy, including gestational hypertension, preeclampsia, and eclampsia, are a worldwide health problem. Hypertensive disorders of pregnancy affect more than 10% of pregnancies and are associated with increased mortality and morbidity for both mother and fetus. Although patients' outcomes and family's experience will always be the primary concern regarding hypertensive complications during pregnancy, the economic aspect of this disease is also worth noting. Compared with normotensive pregnancies, those related with hypertension resulted in an excess increase in hospitalization and healthcare cost. Hence, the focus of this review is to analyze hypertensive disorders of pregnancy and to present practical tips with clear instructions for the clinical management of hypertensive disorders of pregnancy. This overview offers a detailed approach from the diagnosis to treatment and follow-up of a pregnant women with hypertension, evidence based, to support these instructions.

The evaluation of some serum immunochemical markers in early onset pre-eclamptic women from Algeria

PROBLEM

Progress in understanding the underlying mechanism responsible for the syndrome pre-eclampsia should reconfigure antenatal clinical care and minimize human and financial costs, yet at present there is no accurate theory that permits development of reliable predictive tests and prophylactic intervention to mitigate disease. To contribute to this ongoing effort, we aimed to assess various circulating markers pertaining to different theories.

METHOD OF STUDY

Serum samples from thirty-four women with established early onset preeclampsia (ePE) were assessed in terms of oxidative stress (malondialdehyde- MDA), angiogenic status (PlGF & sFLT-1), complement system (The alternative pathway -AP₅₀ & complement factor H- CFH) and circulating inflammatory markers (Interleukin 6- IL-6 & Procalcitonin- PCT). Control groups of gestational age matched patients included 20 gestational hypertensive (GH) and 6 normotensive pregnant women (NPW).

RESULTS

Our work shows that PlGF is the only serum marker who does exhibit a continued decrease from NPW to GH to ePE (r_pearson = -0.428, p = .002). The ePE group had a profound impairment in circulating PlGF (66.93 ± 20.62 pg/ml) compared to GH (142.67 ± 39.79 pg/ml; p = .069) and NPW (636.83 ± 392.66 pg/ml; p = .002). Then, PlGF >71.29 pg/ml pg/ml is the cut-off that has the highest negative predictive value enabling exclusion of ePE (Sp 78%, Se 70%, p = .000). No such interesting results could be obtained with the other markers.

CONCLUSION

Our data confirm that the angiogenic factor PlGF may be highly relevant in biological mechanisms underlying the development of ePE. This article is protected by copyright. All rights reserved.

Using ultrasound and angiogenic markers from a 19- to 23-week assessment to inform the subsequent diagnosis of preeclampsia

BACKGROUND

A definition of preeclampsia that incorporates the assessment of maternal, fetal, and uteroplacental status would optimize the identification of pregnancies at risk of complications at term gestational age. This definition would include "carrying forward" angiogenic test results from 35 to 36 weeks of gestation to term gestational age. Would this approach still be useful if testing is performed earlier or at a routine midgestation scan and the result is used to inform the diagnosis of preeclampsia that developed thereafter?

OBJECTIVE

This study aimed to evaluate whether fetoplacental assessment at a 19- to 23-week scan could be "carried forward" to contribute to the classification of preeclampsia and improve the detection of women and fetuses at risk of adverse outcomes associated with hypertension.

STUDY DESIGN

In this prospective cohort study of singleton pregnancies at 2 maternity hospitals in England (October 2011 to March 2020), women attending a routine hospital visit at 19 to 23 weeks of gestation underwent an assessment that included history, ultrasonographic estimated fetal weight, Doppler measurements of the pulsatility index in uterine arteries, and serum placental growth factor. Preeclampsia was defined according to various definitions: (1) traditional, based on new-onset proteinuria at ≥20 weeks of gestation; (2) 2013 American College of Obstetricians and Gynecologists; (3) 2018 International Society for the Study of Hypertension in Pregnancy maternal factor; (4) 2018 International Society for the Study of Hypertension in Pregnancy maternal-fetal factor (death or growth restriction), based on ultrasound scans at the 19 0/7 to 23 6/7 week of gestation (an estimated fetal weight of <3rd percentile or estimated fetal weight between the 3rd and 10th percentiles with a uterine artery pulsatility index of >95th percentile); and (5) 2021 International Society for the Study of Hypertension in Pregnancy maternal-fetal factor plus placental growth factor (with abnormal placental growth factor defined as an estimated fetal weight of <5th percentile for gestational age). The detection rates for outcomes of interest (ie, severe maternal hypertension, major maternal morbidity, perinatal mortality or major neonatal morbidity, neonatal intensive care unit admission ≥48 hours, and birthweight of <3rd percentile) ascertained by health record review were compared using the chi-square test. A P value of <.05 was considered statistically significant.

RESULTS

Among 40,241 singleton pregnancies, preeclampsia incidence varied by definition, from lows of 2.6% (traditional) and 3.0% (American College of Obstetricians and Gynecologists) to a high of 3.8% (International Society for the Study of Hypertension in Pregnancy maternal-fetal factor plus placental growth factor). The International Society for the Study of Hypertension in Pregnancy maternal-fetal factor plus placental growth factor definition (vs the traditional) best identified women who developed adverse outcomes: severe hypertension (detection rate: 70.6% vs 52.8%; P<.001), major maternal morbidity (detection rate: 100% vs 87.5%; P=.027), perinatal mortality or major morbidity (detection rate: 84.6% vs 69.5%; P=.004), neonatal intensive care unit admission ≥48 hours (detection rate: 76.6% vs 63.2%;, P=.0002), and birthweight of <3rd percentile (detection rate: 81.3% vs 61.9%; P<.0001]. The detection rates improved, going from the American College of Obstetricians and Gynecologists definition to the International Society for the Study of Hypertension in Pregnancy maternal-fetal factor plus placental growth factor definition, for severe hypertension (11.4%; P=.003), perinatal mortality or major morbidity (10.6%; P=.03), neonatal intensive care unit admission ≥48 hours (8.6%; P=.01), and birthweight of <3rd percentile (16.2%; P<.001). However, going from the International Society for the Study of Hypertension in Pregnancy maternal-fetal factor definition to the International Society for the Study of Hypertension in Pregnancy maternal-fetal factor plus placental growth factor definition, the detection of fetuses with a birthweight of <3rd percentile improved by 7.0% (P=.01), but no other improvement was seen for severe hypertension (1.7%; P=.33), major maternal morbidity (0%), perinatal mortality or major morbidity (4.0%; P=.20), and neonatal intensive care unit admission ≥48 hours (3.2%; P=.17).

CONCLUSION

The criteria for uteroplacental dysfunction (including placental growth factor) from the 19- to 23-week assessment can be used in the assessment of women who are later suspected of having PE, to best identify pregnancies at risk of adverse outcomes.

Clinical tools and biomarkers to predict preeclampsia

Preeclampsia is pregnancy-specific, and significantly contributes to maternal, and perinatal morbidity and mortality worldwide. An effective predictive test for preeclampsia would facilitate early diagnosis, targeted surveillance and timely delivery; however limited options currently exist. A first-trimester screening algorithm has been developed and validated to predict preterm preeclampsia, with poor utility for term disease, where the greatest burden lies. Biomarkers such as sFlt-1 and placental growth factor are also now being used clinically in cases of suspected preterm preeclampsia; their high negative predictive value enables confident exclusion of disease in women with normal results, but sensitivity is modest. There has been a concerted effort to identify potential novel biomarkers that might improve prediction. These largely originate from organs involved in preeclampsia's pathogenesis, including placental, cardiovascular and urinary biomarkers. This review outlines the clinical imperative for an effective test and those already in use and summarises current preeclampsia biomarker research.