Placental growth factor as a marker of fetal growth restriction caused by placental dysfunction

The value of angiogenetic biomarkers in the detection of early onset fetal growth restriction

OBJECTIVE

The identification of fetal growth restriction (FGR) due to uteroplacental insufficiency is important to improve perinatal outcomes. To distinguish FGR from small for gestational age (SGA), FGR consensus definition is currently based on biometry and/or additional biophysical parameters. This study aims to verify if this definition might be modified by including circulating angiogenic factors.

STUDY DESIGN

This historical cohort study included singleton pregnancies with SGA fetuses after 20 weeks. All patients underwent detailed ultrasound and measurements of soluble fms-like tyrosine kinase 1 (sFlt-1) and placental growth factor (PlGF) at first assessment. ISUOG criteria for FGR were applied. Total PlGF was calculated using free PlGF, sFlt-1 and a receptor pharmacology model, and multiple of the median (MoM) values for sFlt-1, free PlGF, total PlGF and sFlt-1/PlGF ratio were calculated to adjust for gestational age.

RESULTS

72 pregnancies with SGA were first evaluated at median (IQR) of 28+5 (26+2 -31+3) weeks' gestation, and 51 fetuses (70.8 %) satisfied the FGR consensus definition. Pregnancies with FGR showed significantly lower levels of free and total PlGF MoM (0.12, 95 % IQR: 0.07-0.36 vs 0.32, 95 % IQR: 0.20-0.53, p = 0.008) and 0.26, 95 % CI: 0.16-0.55 vs 0.43, 95 % IQR: 0.23-0.53, p = 0.028) respectively; and higher sFlt-1 MoM (4.62, 95 % IQR: 1.80-7.30 vs 1.74, 95 % IQR:1.11-3.61, p = 0.014) than pregnancies not classified as FGR. Free and total PlGF MoM correlated significantly with gestational age at delivery (r = 0.776, p < 0.001 and r = 0.707, p < 0.001, respectively). sFlt-1 MoM and sFlt-1/PlGF ratio MoM also correlated with gestational age at delivery (r = -0.681, p < 0.001 and r = -0.823, p < 0.001). Six cases identified as FGR at first ultrasound were not confirmed at birth showing significantly higher levels of free PlGF MoM (0.77, 95 % IQR: 0.27-3.07 vs 0.17, 95 % IQR: 0.08-0.43, p = 0.022).

CONCLUSION

These findings show that total as well as free PlGF levels are lower in pregnancies affected with placental growth restriction. Angiogenic biomarkers might improve the differentiation between placental growth restriction and constitutional smallness. Further studies are needed to determine how to integrate them into the current definitions of FGR.

Does the use of angiogenic biomarkers for the management of preeclampsia and fetal growth restriction improve outcomes?: Challenging the current status quo

Monitoring and timing of delivery in preterm preeclampsia and fetal growth restriction is one of the biggest challenges in Obstetrics. Finding the optimal time of delivery of these fetuses usually involves a trade-off between the severity of the disease and prematurity. So far, most clinical guidelines recommend the use of a combination between clinical, laboratory and ultrasound markers to guide the time of delivery. Angiogenic biomarkers, especially placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1), have gained significant attention in recent years for their potential role in the prediction and diagnosis of placenta-related disorders including preeclampsia and fetal growth restriction. Another potential clinical application of the angiogenic biomarkers is for the differential diagnosis of patients with chronic kidney disease, as this condition shares similar clinical features with preeclampsia. Consequently, angiogenic biomarkers have been advocated as tools for monitoring and deciding the optimal time of the delivery of fetuses affected by placental dysfunction. In this clinical opinion, we critically review the available literature on PlGF and sFlt-1 for the surveillance and time of the delivery in fetuses affected by preterm preeclampsia and fetal growth restriction. Moreover, we explore the use of angiogenic biomarkers for the differentiation between chronic kidney disease and superimposed preeclampsia.

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.

Maternal Blood Angiogenic Factors and the Prediction of Critical Adverse Perinatal Outcomes Among Small-for-Gestational-Age Pregnancies

OBJECTIVE

Our objective was to determine whether maternal blood angiogenic factors in suspected-small-for-gestational-age (sSGA) fetuses can predict critical adverse perinatal outcomes (CAPO) and improve risk assessment.

METHODS

Women with singleton pregnancies diagnosed with sSGA, between 24 and 356/7 weeks' gestation, were included. Clinical and sonographic comprehensive evaluations were performed at enrolment. Plasma angiogenic factors, soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF), were obtained at diagnosis. In parallel, three attending maternal-fetal-medicine specialists predicted the risk (1-5 scale) of these pregnancies to develop CAPO, based on the clinical presentation. CAPOs were defined as prolonged neonatal intensive care unit hospitalization, fetal or neonatal death, and major neonatal morbidity. Statistical analysis included sensitivity, specificity, positive and negative predictive values, and receiver-operating characteristic (ROC) curve analyses.

RESULTS

Of the 79 cases included, 32 were complicated by CAPO (40.5%). In SGA fetuses with CAPO, the sFlt-1/PlGF ratio was higher (p < 0.001) and PlGF was lower (p < 0.001) as compared with uncomplicated pregnancies. The areas under the ROC curves for specialists were 0.913, 0.824, and 0.811 and for PlGF and sFlt-1/PlGF ratio 0.926 and 0.900, respectively. CAPO was more common in pregnancies with absent end-diastolic flow or reversed end-diastolic flow (AEDF or REDF) in the umbilical artery upon enrolment (91.6%). Yet, 65.6% of cases involving CAPO occurred in patients without AEDF or REDF, and 66.6% of these cases were not identified by one or more of the experts. The sFlt-1/PlGF ratio identified 92.9% of the experts' errors in this group and 100% of the errors in cases with AEDF or REDF.

CONCLUSION

Among sSGA pregnancies prior to 36 weeks' gestation, angiogenic factors testing can identify most cases later complicated with CAPO. Our data demonstrate for the first time that these markers can reduce clinician judgment errors. Incorporation of these measures into decision-making algorithms could potentially improve management, outcomes, and even health care costs.

KEY POINTS

· Angiogenic factors at diagnosis of sSGA can be used to predict CAPO.. · The sFlt-1/PlGF ratio can flag sSGA pregnancies at increased risk.. · The sFlt-1/PlGF ratio at admission of sSGA adds to clinical assessment..

Prediction of preterm birth in women with fetal growth restriction - Is the weekly change in sFlt-1/PlGF ratio or PlGF levels useful?

INTRODUCTION

To assess the rate of change in soluble fms-like tyrosine kinase-1/placental growth factor (sFlt-1/PlGF) ratio and PlGF levels per week compared to a single sFlt-1/PlGF ratio or PlGF level to predict preterm birth for pregnancies complicated by fetal growth restriction.

MATERIAL AND METHODS

A prospective cohort study of pregnancies complicated by isolated fetal growth restriction. Maternal serum PlGF levels and the sFlt-1/PlGF ratio were measured at 4-weekly intervals from recruitment to delivery. We investigated the utility of PlGF levels, sFlt-1/PlGF ratio, change in PlGF levels per week or sFlt-1/PlGF ratio per week. Cox-proportional hazard models and Harrell's C concordance statistic were used to evaluate the effect of biomarkers on time to preterm birth.

RESULTS

The total study cohort was 158 pregnancies comprising 91 (57.6%) with fetal growth restriction and 67 (42.4%) with appropriate for gestational age controls. In the fetal growth restriction cohort, sFlt-1/PlGF ratio and PlGF levels significantly affected time to preterm birth (Harrell's C: 0.85-0.76). The rate of increase per week of the sFlt-1/PlGF ratio (hazard ratio [HR] 3.91, 95% confidence interval [CI]: 1.39-10.99, p = 0.01, Harrell's C: 0.74) was positively associated with preterm birth but change in PlGF levels per week was not (HR 0.65, 95% CI: 0.25-1.67, p = 0.37, Harrell's C: 0.68).

CONCLUSIONS

Both a high sFlt-1/PlGF ratio and low PlGF levels are predictive of preterm birth in women with fetal growth restriction. Although the rate of increase of the sFlt-1/PlGF ratio predicts preterm birth, it is not superior to either a single elevated sFlt-1/PlGF ratio or low PlGF level.

Distinct properties of putative trophoblast stem cells established from somatic cell nuclear-transferred pig blastocysts

BACKGROUND

Genetically modified pigs are considered ideal models for studying human diseases and potential sources for xenotransplantation research. However, the somatic cell nuclear transfer (SCNT) technique utilized to generate these cloned pig models has low efficiency, and fetal development is limited due to placental abnormalities.

RESULTS

In this study, we unprecedentedly established putative porcine trophoblast stem cells (TSCs) using SCNT and in vitro-fertilized (IVF) blastocysts through the activation of Wing-less/Integrated (Wnt) and epidermal growth factor (EGF) pathways, inhibition of transforming growth factor-β (TGFβ) and Rho-associated protein kinase (ROCK) pathways, and supplementation with ascorbic acid. We also compared the transcripts of putative TSCs originating from SCNT and IVF embryos and their differentiated lineages. A total of 19 porcine TSCs exhibiting typical characteristics were established from SCNT and IVF blastocysts (TSCsNT and TSCsIVF). Compared with the TSCsIVF, TSCsNT showed distinct expression patterns suggesting unique TSCsNT characteristics, including decreased mRNA expression of genes related to apposition, steroid hormone biosynthesis, angiopoiesis, and RNA stability.

CONCLUSION

This study provides valuable information and a powerful model for studying the abnormal development and dysfunction of trophoblasts and placentas in cloned pigs.

Placental growth factor and fetoplacental Doppler indices in combination predict preterm birth reliably in pregnancies complicated by fetal growth restriction

OBJECTIVE

To assess the association between placental biomarkers (placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1)/PlGF ratio) and fetoplacental Doppler indices (umbilical artery (UA) pulsatility index (PI) and uterine artery (UtA) PI) in various combinations for predicting preterm birth (PTB) in pregnancies complicated by fetal growth restriction (FGR).

METHODS

This was a prospective observational cohort study, performed at Mater Mother's Hospital in Brisbane, Queensland, Australia, from May 2022 to June 2023, of pregnancies complicated by FGR and appropriate-for-gestational-age (AGA) pregnancies. Maternal serum PlGF levels, sFlt-1/PlGF ratio, UA-PI and UtA-PI were measured at 2-4-weekly intervals from recruitment until delivery. Harrell's concordance statistic (Harrell's C) was used to evaluate multivariable Cox proportional hazards regression models featuring various combinations of placental biomarkers and fetoplacental Doppler indices to ascertain the best combination to predict PTB (< 37 weeks). Multivariable Cox regression models were used with biomarkers as time-varying covariates.

RESULTS

The study cohort included 320 singleton pregnancies, comprising 179 (55.9%) affected by FGR, defined according to a Delphi consensus, and 141 (44.1%) with an AGA fetus. In the FGR cohort, both low PlGF levels and elevated sFlt-1/PlGF ratio were associated with significantly shorter time to PTB. Low PlGF was a better predictor of PTB than was either sFlt-1/PlGF ratio or a combination of PlGF and sFlt-1/PlGF ratio (Harrell's C, 0.81, 0.78 and 0.79, respectively). Although both Doppler indices were significantly associated with time to PTB, in combination they were better predictors of PTB than was either UA-PI > 95th centile or UtA-PI > 95th centile alone (Harrell's C, 0.82, 0.75 and 0.76, respectively). Predictive utility for PTB was best when PlGF < 100 ng/L, UA-PI > 95th centile and UtA-PI > 95th centile were combined (Harrell's C, 0.88) (hazard ratio, 32.99; 95% CI, 10.74-101.32).

CONCLUSIONS

Low maternal serum PlGF level (< 100 ng/L) and abnormal fetoplacental Doppler indices (UA-PI > 95th centile and UtA-PI > 95th centile) in combination have the greatest predictive utility for PTB in pregnancies complicated by FGR. Their assessment may help guide clinical management of these complex pregnancies. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Intrauterine growth restriction in piglets modulates postnatal immune function and hepatic transcriptional responses independently of energy intake

Introduction: Insufficient prenatal nutrition can affect fetal development and lead to intrauterine growth restriction (IUGR). The aim of this study was to investigate hepatic transcriptional responses and innate immune function in piglets suffering from IUGR compared to normal-sized piglets at 3 days of age and explore whether the provision of an energy-rich supplement at birth could modulate these parameters. Methods: A total of 68 piglets were included in the study. Peripheral blood mononuclear cells were harvested for LPS stimulation, and organs were harvested post-mortem to quantify relative weights. Liver tissue was utilized for RNA sequencing coupled with gene-set enrichment analysis. Results: IUGR resulted in increased expression of genes such as PDK4 and substantial alterations in transcriptional pathways related to metabolic activity (e.g., citric acid and Krebs cycles), but these changes were equivalent in piglets given an energy-rich supplement or not. Transcriptomic analysis and serum biochemistry suggested altered glucose metabolism and a shift toward oxidation of fatty acids. IUGR piglets also exhibited suppression of genes related to innate immune function (e.g., CXCL12) and pathways related to cell proliferation (e.g., WNT and PDGF signaling). Moreover, they produced less IL-1β in response to LPS stimulation and had lower levels of blood eosinophils than normal-sized piglets. Discussion: Taken together, our results indicate that IUGR results in early-life alterations in metabolism and immunity that may not be easily restored by the provision of exogenous energy supplementation.

Directive clinique no 442 : Retard de croissance intra-utérin : Dépistage, diagnostic et prise en charge en contexte de grossesse monofœtale

OBJECTIF

Le retard de croissance intra-utérin est une complication obstétricale fréquente qui touche jusqu'à 10 % des grossesses dans la population générale et qui est le plus souvent due à une pathologie placentaire sous-jacente. L'objectif de la présente directive clinique est de fournir des déclarations sommaires et des recommandations pour appuyer un protocole clinique de dépistage, diagnostic et prise en charge du retard de croissance intra-utérin pour les grossesses à risque ou atteintes.

POPULATION CIBLE

Toutes les patientes enceintes menant une grossesse monofœtale. BéNéFICES, RISQUES ET COûTS: La mise en application des recommandations de la présente directive devrait améliorer la compétence des cliniciens quant à la détection du retard de croissance intra-utérin et à la réalisation des interventions indiquées. DONNéES PROBANTES: La littérature publiée a été colligée par des recherches effectuées jusqu'en septembre 2022 dans les bases de données PubMed, Medline, CINAHL et Cochrane Library en utilisant un vocabulaire contrôlé au moyen de termes MeSH pertinents (fetal growth retardation and small for gestational age) et de mots-clés (fetal growth, restriction, growth retardation, IUGR, FGR, low birth weight, small for gestational age, Doppler, placenta, pathology). Seuls les résultats de revues systématiques, d'essais cliniques randomisés ou comparatifs et d'études observationnelles ont été retenus. La littérature grise a été obtenue par des recherches menées dans des sites Web d'organismes s'intéressant à l'évaluation des technologies dans le domaine de la santé et d'organismes connexes, dans des collections de directives cliniques, des registres d'essais cliniques et des sites Web de sociétés de spécialité médicale nationales et internationales. MéTHODES DE VALIDATION: Les auteurs ont évalué la qualité des données probantes et la force des recommandations en utilisant le cadre méthodologique GRADE (Grading of Recommendations Assessment, Development and Evaluation). Voir l'annexe A en ligne (tableau A1 pour les définitions et tableau A2 pour l'interprétation des recommandations fortes et conditionnelles [faibles]). PROFESSIONNELS CONCERNéS: Obstétriciens, médecins de famille, infirmières, sages-femmes, spécialistes en médecine fœto-maternelle, radiologistes et autres professionnels de la santé qui prodiguent des soins aux patientes enceintes. RéSUMé POUR TWITTER: Mise à jour de la directive sur le dépistage, le diagnostic et la prise en charge du retard de croissance intra-utérin pour les grossesses à risque ou atteintes. DÉCLARATIONS SOMMAIRES: RECOMMANDATIONS: Prédiction du retard de croissance intra-utérin Prévention du retard de croissance intra-utérin Détection du retard de croissance intra-utérin Examens en cas de retard de croissance intra-utérin soupçonné Prise en charge du retard de croissance intra-utérin précoce Prise en charge du retard de croissance intra-utérin tardif Prise en charge du post-partum et consultations préconception.

Guideline No. 442: Fetal Growth Restriction: Screening, Diagnosis, and Management in Singleton Pregnancies

OBJECTIVE

Fetal growth restriction is a common obstetrical complication that affects up to 10% of pregnancies in the general population and is most commonly due to underlying placental diseases. The purpose of this guideline is to provide summary statements and recommendations to support a clinical framework for effective screening, diagnosis, and management of pregnancies that are either at risk of or affected by fetal growth restriction.

TARGET POPULATION

All pregnant patients with a singleton pregnancy.

BENEFITS, HARMS, AND COSTS

Implementation of the recommendations in this guideline should increase clinician competency to detect fetal growth restriction and provide appropriate interventions.

EVIDENCE

Published literature in English was retrieved through searches of PubMed or MEDLINE, CINAHL, and The Cochrane Library through to September 2022 using appropriate controlled vocabulary via MeSH terms (fetal growth retardation and small for gestational age) and key words (fetal growth, restriction, growth retardation, IUGR, FGR, low birth weight, small for gestational age, Doppler, placenta, pathology). Results were restricted to systematic reviews, randomized controlled trials/controlled clinical trials, and observational studies. Grey literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

VALIDATION METHODS

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Table A1 for definitions and Table A2 for interpretations of strong and conditional [weak] recommendations).

INTENDED AUDIENCE

Obstetricians, family physicians, nurses, midwives, maternal-fetal medicine specialists, radiologists, and other health care providers who care for pregnant patients.

TWEETABLE ABSTRACT

Updated guidelines on screening, diagnosis, and management of pregnancies at risk of or affected by FGR.

SUMMARY STATEMENTS

RECOMMENDATIONS: Prediction of FGR Prevention of FGR Detection of FGR Investigations in Pregnancies with Suspected Fetal Growth Restriction Management of Early-Onset Fetal Growth Restriction Management of Late-Onset FGR Postpartum management and preconception counselling.

Scaling the EVERREST of severe, early-onset fetal growth restriction

Severe, early-onset fetal growth restriction is a leading cause of medically indicated preterm birth and substantially increases the risk for perinatal death or disability. No treatments exist to improve fetal growth or safely prolong pregnancy. Furthermore, wide-ranging phenotypes limit the accurate prediction of pregnancy outcome. In this issue of the JCI, Spencer and colleagues combine a discovery-science approach with ultrasound parameters to identify the most discriminative models for predicting either the primary outcome of fetal or neonatal death, or a secondary outcome of death or delivery at 28 weeks of gestation or earlier. Their findings can better individualize patient counseling but, just as compellingly, provide the capacity to identify those pregnancies that are at such considerable risk as to justify enrollment in paradigm-shifting interventional trials that are in the pipeline.

Maternal PlGF and umbilical Dopplers predict pregnancy outcomes at diagnosis of early-onset fetal growth restriction

BACKGROUNDSevere, early-onset fetal growth restriction (FGR) causes significant fetal and neonatal mortality and morbidity. Predicting the outcome of affected pregnancies at the time of diagnosis is difficult, thus preventing accurate patient counseling. We investigated the use of maternal serum protein and ultrasound measurements at diagnosis to predict fetal or neonatal death and 3 secondary outcomes: fetal death or delivery at or before 28+0 weeks, development of abnormal umbilical artery (UmA) Doppler velocimetry, and slow fetal growth.METHODSWomen with singleton pregnancies (n = 142, estimated fetal weights [EFWs] below the third centile, less than 600 g, 20+0 to 26+6 weeks of gestation, no known chromosomal, genetic, or major structural abnormalities) were recruited from 4 European centers. Maternal serum from the discovery set (n = 63) was analyzed for 7 proteins linked to angiogenesis, 90 additional proteins associated with cardiovascular disease, and 5 proteins identified through pooled liquid chromatography and tandem mass spectrometry. Patient and clinician stakeholder priorities were used to select models tested in the validation set (n = 60), with final models calculated from combined data.RESULTSThe most discriminative model for fetal or neonatal death included the EFW z score (Hadlock 3 formula/Marsal chart), gestational age, and UmA Doppler category (AUC, 0.91; 95% CI, 0.86-0.97) but was less well calibrated than the model containing only the EFW z score (Hadlock 3/Marsal). The most discriminative model for fetal death or delivery at or before 28+0 weeks included maternal serum placental growth factor (PlGF) concentration and UmA Doppler category (AUC, 0.89; 95% CI, 0.83-0.94).CONCLUSIONUltrasound measurements and maternal serum PlGF concentration at diagnosis of severe, early-onset FGR predicted pregnancy outcomes of importance to patients and clinicians.TRIAL REGISTRATIONClinicalTrials.gov NCT02097667.FUNDINGThe European Union, Rosetrees Trust, Mitchell Charitable Trust.

From Molecules to Imaging: Assessment of Placental Hypoxia Biomarkers in Placental Insufficiency Syndromes

Placental hypoxia poses significant risks to both the developing fetus and the mother during pregnancy, underscoring the importance of early detection and monitoring. Effectively identifying placental hypoxia and evaluating the deterioration in placental function requires reliable biomarkers. Molecular biomarkers in placental tissue can only be determined post-delivery and while maternal blood biomarkers can be measured over time, they can merely serve as proxies for placental function. Therefore, there is an increasing demand for non-invasive imaging techniques capable of directly assessing the placental condition over time. Recent advancements in imaging technologies, including photoacoustic and magnetic resonance imaging, offer promising tools for detecting and monitoring placental hypoxia. Integrating molecular and imaging biomarkers may revolutionize the detection and monitoring of placental hypoxia, improving pregnancy outcomes and reducing long-term health complications. This review describes current research on molecular and imaging biomarkers of placental hypoxia both in human and animal studies and aims to explore the benefits of an integrated approach throughout gestation.

Developments in functional imaging of the placenta

The placenta is both the literal and metaphorical black box of pregnancy. Measurement of the function of the placenta has the potential to enhance our understanding of this enigmatic organ and serve to support obstetric decision making. Advanced imaging techniques are key to support these measurements. This review summarises emerging imaging technology being used to measure the function of the placenta and new developments in the computational analysis of these data. We address three important examples where functional imaging is supporting our understanding of these conditions: fetal growth restriction, placenta accreta, and twin-twin transfusion syndrome.

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.

Circulating biomarkers associated with placental dysfunction and their utility for predicting fetal growth restriction

Fetal growth restriction (FGR) leading to low birth weight (LBW) is a major cause of neonatal morbidity and mortality worldwide. Normal placental development involves a series of highly regulated processes involving a multitude of hormones, transcription factors, and cell lineages. Failure to achieve this leads to placental dysfunction and related placental diseases such as pre-clampsia and FGR. Early recognition of at-risk pregnancies is important because careful maternal and fetal surveillance can potentially prevent adverse maternal and perinatal outcomes by judicious pregnancy surveillance and careful timing of birth. Given the association between a variety of circulating maternal biomarkers, adverse pregnancy, and perinatal outcomes, screening tests based on these biomarkers, incorporating maternal characteristics, fetal biophysical or circulatory variables have been developed. However, their clinical utility has yet to be proven. Of the current biomarkers, placental growth factor and soluble fms-like tyrosine kinase 1 appear to have the most promise for placental dysfunction and predictive utility for FGR.

Angiogenic imbalance in pre-eclampsia and fetal growth restriction: enhanced soluble fms-like tyrosine kinase-1 binding or diminished production of placental growth factor?

OBJECTIVES

To assess levels of total placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1) and free PlGF in women with pre-eclampsia (PE) with or without a small-for-gestational-age (SGA) neonate in order to establish whether low free PlGF levels associated with PE and SGA are due to enhanced sFlt-1 binding or decreased PlGF production.

METHODS

This was a secondary analysis of a prospective multicenter cohort study involving 407 pregnancies with suspected or confirmed PE, in which total PlGF levels were calculated from measured sFlt-1 and free PlGF levels. The control group included women who were suspected to have PE at a certain point in pregnancy but did not develop PE. The analysis was stratified according to whether PE was early- or late-onset (gestational age < 34 weeks vs ≥ 34 weeks) and according to the presence of SGA at birth, which was used as a proxy of fetal growth restriction in the absence of Doppler ultrasound and biometric data.

RESULTS

In early-onset PE, both women with and those without SGA had lower free (19 and 45 pg/mL) and total (44 and 100 pg/mL) PlGF levels compared with women without PE (free and total PlGF, 300 and 381 pg/mL, respectively). SGA alone did not affect free and total PlGF in this condition (free and total PlGF, 264 and 352 pg/mL, respectively). Observations in women with late-onset PE were similar, although the changes were more modest. Both SGA (gestational age < 34 weeks) and PE were individually associated with increased sFlt-1 and, in women with both PE and SGA, the upregulation of sFlt-1 occurred in a synergistic manner, thus resulting in the highest sFlt-1/free PlGF ratio in this group. This occurred in both early- and late-onset PE.

CONCLUSIONS

Particularly in pregnancies with early-onset PE and SGA, diminished PlGF production is an important cause of low free PlGF levels. Under such conditions, sFlt-1 lowering is unlikely to restore the angiogenic balance. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Early Mid-pregnancy Blood-Based Proteins as Possible Biomarkers of Increased Infant Birth Size in Sex-Stratified Analyses

The objective of this study was to evaluate the associations of 92 maternal blood-based proteins with increased infant birth size. The study was performed at the Uppsala University Hospital, Sweden, and included 857 mother and child dyads. The mean age of the women was 30.3 years, and 53.2% were nulliparous. Blood samples were collected at mean 18 + 2 weeks' gestation, and the Olink cardiovascular II panel was used to measure 92 proteins, either known to be or suspected to be markers of cardiovascular and inflammatory disease in humans. Multiple linear regression models adjusted for maternal age, parity, pre-conception BMI, height, and smoking were performed to evaluate the association of each individual protein with infant birth size. We also performed sex-stratified analyses. Eight proteins (Matrix metalloproteinase-12 (MMP-12), Prostasin (PRSS8), Adrenomedullin (ADM), Pappalysin-1 (PAPP-A), Angiotensin-converting enzyme 2 (ACE2), Sortilin (SORT1), Lectin-like oxidized LDL receptor 1 (LOX-1), and Thrombomodulin (TM)) were associated with infant birth size after false discovery rate adjustment. In the analyses including only female infants, ten proteins (MMP-12, Growth/differentiation factor 2 (GDF-2), PRSS8, SORT1, ADM, Interleukin-1 receptor antagonist protein (IL-1ra), Leptin (LEP), ACE2, TM, and Tumor necrosis factor receptor superfamily member 11A (TNFRSF11A)) were associated with infant birth size. Two proteins (PAPP-A and PRSS8) were associated with infant birth size among male infants. Our study suggests several proteins as potential biomarkers for increased birth weight, and our findings could act as a base for future research to identify new potential markers that could be added to improve screening for large infants.

Expression profile of genes related to pregnancy maintenance in Dromedary Camel during the first trimester

So far, few signals involved in embryo-maternal dialogue have been identified in pregnant she-camel. Our objective was to investigate expression profiles of genes relevant to uterine extracellular matrix remodeling (ITGB4, SLCO2A1, FOS, and JUN), uterine tissue vascularization, and placental formation (VEGFA, PGF, and PDGFA), embryonic growth and development (IGF1 and PTEN), plus cell death of uterine tissue (BCL2) in early pregnant versus non-pregnant she-camels. Forty genital tracts (20 pregnant and 20 non-pregnant) and blood samples were collected from abattoirs. Total RNA was extracted from uterine tissues and qRT-PCR was conducted for candidate genes. Serum concentrations of progesterone (P4) and estradiol17-β (E2) were measured. Expression of ITGB4, FOS, and PGF genes increased (P < 0.001) in the right uterine horn of pregnant versus non-pregnant she-camels. Moreover, JUN, SLCO2A1, VEGFA, and PTEN mRNAs were up-regulated (P < 0.001) in various segments of uterine tissues in pregnant groups. The PDGFA transcript was over-expressed (P < 0.001) in both uterine horns of pregnant groups. Additionally, IGF1 was higher (P < 0.001) in the right horn and the uterine body of pregnant groups, and expression of BCL2 was increased (P < 0.001) in the pregnant uterine body. Moreover, serum concentrations of P4 were higher (P < 0.001) and E2 lower (P < 0.05) in pregnant she-camels. Taken together, the fine-tuning of genes related to implantation, matrix formation, vascularization, and placental formation is highly required for successful pregnancy in she-camels.

Perspectives on the Use of Placental Growth Factor (PlGF) in the Prediction and Diagnosis of Pre-Eclampsia: Recent Insights and Future Steps

Pre-eclampsia (PE) is a complex multisystem disease of pregnancy that is becoming increasingly recognized as a state of angiogenic imbalance characterized by low concentrations of placental growth factor (PlGF) and elevated soluble fms-like tyrosine kinase (sFlt-1). PlGF is a protein highly expressed by the placenta with vasculogenic and angiogenic properties, which has a central role in spiral artery remodeling and the development of a low-resistance placental capillary network. PlGF concentrations are significantly lower in women with preterm PE, and these reduced levels have been shown to precede the clinical onset of disease. Subsequently, the clinical utility of maternal serum PlGF has been extensively studied in singleton gestations from as early as 11 to 13 weeks' gestation, utilizing a validated multimarker prediction model, which performs superiorly to the National Institute for Health and Care Excellence (NICE) and American College of Obstetricians and Gynecologists (ACOG) guidelines in the detection of preterm PE. There is extensive research highlighting the role of PlGF-based testing utilizing commercially available assays in accelerating the diagnosis of PE in symptomatic women over 20 weeks' gestation and predicting time-to-delivery, allowing individualized risk stratification and appropriate antenatal surveillance to be determined. "Real-world" data has shown that interpretation of PlGF-based test results can aid clinicians in improving maternal outcomes and a growing body of evidence has implied a role for sFlt-1/PlGF in the prognostication of adverse pregnancy and perinatal events. Subsequently, PlGF-based testing is increasingly being implemented into obstetric practice and is advocated by NICE. This literature review aims to provide healthcare professionals with an understanding of the role of angiogenic biomarkers in PE and discuss the evidence for PlGF-based screening and triage. Prospective studies are warranted to explore if its implementation significantly improves perinatal outcomes, explore the value of repeat PlGF testing, and its use in multiple pregnancies.

Contribution of Second Trimester Sonographic Placental Morphology to Uterine Artery Doppler in the Prediction of Placenta-Mediated Pregnancy Complications

Background: Second-trimester uterine artery Doppler is a well-established tool for the prediction of preeclampsia and fetal growth restriction. At delivery, placentas from affected pregnancies may have gross pathologic findings. Some of these features are detectable by ultrasound, but the relative importance of placental morphologic assessment and uterine artery Doppler in mid-pregnancy is presently unclear. Objective: To characterize the association of second-trimester sonographic placental morphology markers with placenta-mediated complications and determine whether these markers are predictive of placental dysfunction independent of uterine artery Doppler. Methods: This was a retrospective cohort study of patients with a singleton pregnancy at high risk of placental complications who underwent a sonographic placental study at mid-gestation (160/7−246/7 weeks’ gestation) in a single tertiary referral center between 2016−2019. The sonographic placental study included assessment of placental dimensions (length, width, and thickness), placental texture appearance, umbilical cord anatomy, and uterine artery Doppler (mean pulsatility index and early diastolic notching). Placental area and volume were calculated based on placental length, width, and thickness. Continuous placental markers were converted to multiples on medians (MoM). The primary outcome was a composite of early-onset preeclampsia and birthweight < 3rd centile. Results: A total of 429 eligible patients were identified during the study period, of whom 45 (10.5%) experienced the primary outcome. The rate of the primary outcome increased progressively with decreasing placental length, width, and area, and increased progressively with increasing mean uterine artery pulsatility index (PI). By contrast, placental thickness followed a U-shaped relationship with the primary outcome. Placental length, width, and area, mean uterine artery PI and bilateral uterine artery notching were all associated with the primary outcome. However, in the adjusted analysis, the association persisted only for placenta area (adjusted odds ratio [aOR] 0.21, 95%-confidence interval [CI] 0.06−0.73) and mean uterine artery PI (aOR 11.71, 95%-CI 3.84−35.72). The area under the ROC curve was highest for mean uterine artery PI (0.80, 95%-CI 0.71−0.89) and was significantly higher than that of placental area (0.67, 95%-CI 0.57−0.76, p = 0.44). A model that included both mean uterine artery PI and placental area did not significantly increase the area under the curve (0.82, 95%-CI 0.74−0.90, p = 0.255), and was associated with a relatively minor increase in specificity for the primary outcome compared with mean uterine artery PI alone (63% [95%-CI 58−68%] vs. 52% [95%-CI 47−57%]). Conclusion: Placental area is independently associated with the risk of placenta-mediated complications yet, when combined with uterine artery Doppler, did not further improve the prediction of such complications compared with uterine artery Doppler alone.

Reduced Birth Weight and Exposure to Per- and Polyfluoroalkyl Substances: A Review of Possible Underlying Mechanisms Using the AOP-HelpFinder

Prenatal exposure to per- and polyfluorinated substances (PFAS) may impair fetal growth. Our knowledge of the underlying mechanisms is incomplete. We used the Adverse Outcome Pathway (AOP)-helpFinder tool to search PubMed for studies published until March 2021 that examined PFAS exposure in relation to birth weight, oxidative stress, hormones/hormone receptors, or growth signaling pathways. Of these 1880 articles, 106 experimental studies remained after abstract screening. One clear finding is that PFAS are associated with oxidative stress in in vivo animal studies and in vitro studies. It appears that PFAS-induced reactive-oxygen species (ROS) generation triggers increased peroxisome proliferator-activated receptor (PPAR)γ expression and activation of growth signaling pathways, leading to hyperdifferentiation of pre-adipocytes. Fewer proliferating pre-adipocytes result in lower adipose tissue weight and in this way may reduce birth weight. PFAS may also impair fetal growth through endocrine effects. Estrogenic effects have been noted in in vivo and in vitro studies. Overall, data suggest thyroid-damaging effects of PFAS affecting thyroid hormones, thyroid hormone gene expression, and histology that are associated in animal studies with decreased body and organ weight. The effects of PFAS on the complex relationships between oxidative stress, endocrine system function, adipogenesis, and fetal growth should be further explored.

Placental Growth Factor in First Trimester of Pregnancy for Prediction of Maternal and Perinatal Adverse Outcomes

Purpose of the study

Placental growth factor (PLGF) is an angiogenic factor in pregnancy. To find out correlation of plasma levels of placental growth factor in first trimester of pregnancy in Indian women who develop maternal and perinatal adverse outcomes was the aim of the study.

Methods

A prospective longitudinal noninterventional study was done in the department of Obstetrics and Gynecology after obtaining ethics approval. After enrolling patients in the first trimester (11 weeks to 13 weeks 6 days), a questionnaire was filled for demographic characteristics. Uterine artery doppler was done for every patient and blood sample (5 ml) was taken by venu puncture of median cubital vein. Serum levels of PLGF were measured by enzyme linked immunosorbent assay using Thermo Scientific Pierce Human PLGF kit (Thermo Fisher Scientific, Inc., Waltham, MA, USA). Patients were followed for their whole antenatal period and delivery outcomes.

Results

Incidence of preeclampsia in our study was 9.3% (15/161) and fetal growth restriction (FGR) was 19.8% (32/161). Neither BMI nor nulliparity was found to have statistically significant correlation with development of preeclampsia. However, history of preeclampsia was found to be significant risk factor for prediction of preeclampsia (p value < 0.04). Plasma levels of PLGF were significantly lower in preeclampsia and FGR group and this difference was statistically significant (p value < 0.04). 7.5% still born occurred in complicated group and 10% needed NNU/NICU admission in this group.

Conclusion

Measuring PLGF levels in first trimester of pregnancy can help in prediction of preeclampsia and FGR.

Clinical Assessment of Fetal Well-Being and Fetal Safety Indicators

Delivering safe clinical trials of novel therapeutics is central to enable pregnant women and their babies to access medicines for better outcomes. This review describes clinical monitoring of fetal well‐being and safety. Current pregnancy surveillance includes regular antenatal checks of blood pressure and urine for signs of gestational hypertension. Fetal and placental development is assessed routinely using the first‐trimester “dating” and mid‐trimester “anomaly” ultrasound scans, but the detection of fetal anomalies can continue throughout pregnancy using targeted sonography or magnetic resonance imaging (MRI). Serial sonography can be used to assess fetal size, well‐being, and placental function. Carefully defined reproducible imaging parameters, such as the head circumference (HC), abdominal circumference (AC), and femur length (FL), are combined to calculate an estimate of the fetal weight. Doppler analysis of maternal uterine blood flow predicts placental insufficiency, which is associated with poor fetal growth. Fetal doppler analysis can indicate circulatory decompensation and fetal hypoxia, requiring delivery to be expedited. Novel ways to assess fetal well‐being and placental function using MRI, computerized cardiotocography (CTG), serum circulating fetoplacental proteins, and mRNA may improve the assessment of the safety and efficacy of maternal and fetal interventions. Progress has been made in how to define and grade clinical trial safety in pregnant women, the fetus, and neonate. A new system for improved safety monitoring for clinical trials in pregnancy, Maternal and Fetal Adverse Event Terminology (MFAET), describes 12 maternal and 18 fetal adverse event (AE) definitions and severity grading criteria developed through an international modified Delphi consensus process. This fills a vital gap in maternal and fetal translational medicine research.

Prediction of spontaneous preterm birth and preterm prelabor rupture of membranes using maternal factors, obstetric history and biomarkers of placental function at 11-13 weeks

OBJECTIVES

To determine whether first-trimester biomarkers of placental function can be used to screen for spontaneous preterm birth (sPTB), and to develop prediction models using maternal factors, obstetric history and biomarkers of placental function at 11-13 weeks for the calculation of patient-specific risk for sPTB.

METHODS

This was a retrospective secondary analysis of data derived from a prospective cohort study on first-trimester screening for pre-eclampsia in singleton pregnancies attending for routine Down syndrome screening at 11 + 0 to 13 + 6 weeks' gestation at a tertiary obstetric unit between December 2016 and September 2019. A split-sample internal validation method was used to explore and develop prediction models for all sPTB at < 37 weeks and for PTB at < 37 weeks after preterm prelabor rupture of membranes (PPROM) using maternal risk factors, uterine artery Doppler indices, serum placental growth factor (PlGF), pregnancy-associated plasma protein-A (PAPP-A) and β-human chorionic gonadotropin (β-hCG). Screening performance was assessed using receiver-operating-characteristics (ROC)-curve analysis, with calculation of the areas under the ROC curves (AUCs).

RESULTS

A total of 9298 singleton pregnancies were included in this study. sPTB at < 37 weeks occurred in 362 (3.89%) cases, including 231 (2.48%) cases of PPROM. sPTB at < 34 weeks occurred in 87 (0.94%) cases, including 39 (0.42%) cases of PPROM. Identified maternal risk factors for sPTB at < 37 weeks included chronic hypertension, conception using in-vitro fertilization and history of PTB. Maternal risk factors for PPROM at < 37 weeks included conception using in-vitro fertilization and history of PTB. Median PlGF multiples of the median (MoM) and PAPP-A MoM were significantly reduced in women with sPTB at < 37 weeks, as well as in those who had PPROM, compared to those who delivered at term. Screening by a combination of maternal risk factors, PAPP-A and PlGF achieved better performance in predicting sPTB at < 37 weeks (AUC, 0.630 vs 0.555; detection rate (DR), 24.8% vs 16.6% at a false-positive rate (FPR) of 10%; P ≤ 0.0001) and PPROM at < 37 weeks (AUC, 0.643 vs 0.558; DR, 28.1% vs 17.0% at a FPR of 10%; P ≤ 0.0001) than using maternal risk factors alone. Both models were successfully applied to the internal validation dataset, with AUCs of 0.628 and 0.650, respectively.

CONCLUSIONS

We demonstrated that low levels of maternal serum PAPP-A and PlGF in the first trimester are associated with increased risks of sPTB and PPROM at < 37 weeks. However, further research is needed to identify additional biomarkers to improve the screening performance of the combined model that includes maternal risk factors, PAPP-A and PlGF before clinical application. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Halting the Canadian STRIDER randomised controlled trial of sildenafil for severe, early-onset fetal growth restriction: ethical, methodological, and pragmatic considerations

Objectives

To determine the efficacy and safety of sildenafil citrate to improve outcomes in pregnancies complicated by early-onset, dismal prognosis, fetal growth restriction (FGR). Eligibility: women ≥ 18 years, singleton, 18 + 0–27 + 6 weeks’ gestation, estimated fetal weight < 700 g, low PLFG, and ≥ 1 of (i) abdominal circumference < 10th percentile for gestational age (GA); or (ii) reduced growth velocity and either abnormal uterine artery Doppler or prior early-onset FGR with adverse outcome. Ineligibility criteria included: planned termination or reversed umbilical artery end-diastolic flow. Eligibility confirmed by placental growth factor (PlGF) < 5 th percentile for GA measured post randomization. Women randomly received (1:1) either sildenafil 25 mg three times daily or matched placebo until either delivery or 31 + 6 weeks. Primary outcome: delivery GA. The trial stopped early when Dutch STRIDER signalled potential harm; despite distinct eligibility criteria and IRB and DSMB support to continue, because of futility. NCT02442492 [registered 13/05/2015].

Results

Between May 2017 and June 2018, 21 (90 planned) women were randomised [10 sildenafil; 11 placebo (1 withdrawal)]. Baseline characteristics, PlGF levels, maternal and perinatal outcomes, and adverse events did not differ. Delivery GA: 26 + 6 weeks (sildenafil) vs 29 + 2 weeks (placebo); p = 0.200. Data will contribute to an individual participant data meta-analysis.

Uterine activity in labour and the risk of neonatal encephalopathy: a case control study

OBJECTIVE

To determine the relationship between intrapartum contraction frequency, rest interval duration, and cervical dilation speed and the risk of neonatal hypoxic-ischemic encephalopathy (HIE).

STUDY DESIGN

This was a retrospective case-control study conducted in a maternity hospital in Dublin, Ireland. Babies born without major congenital anomalies between September 2006 and November 2017 at ≥ 35 + 0 weeks' gestational age were eligible. Cases were diagnosed with moderate-severe HIE. The controls were the first eligible baby born before and after each case with normal Apgar scores and not admitted to the neonatal unit. Intrapartum uterine activity was assessed by automated analysis of external tocography recordings. Cervical dilation was assessed by linear interpolation between vaginal examination measurements. The speed of cervical dilation was expressed as the times from 4 to 6 cm, >6 cm to the start of pushing, and from pushing to delivery.

RESULTS

Intrapartum tocographs results were available in 49 of 88 cases and 121 of 176 controls. The median contraction rate in cases was 7.7 (Interquartile range [IQR]: 6.6-9.0) compared to 7.0 in controls (IQR: 6.2-7.9) (p = 0.021). The median rest interval duration was 56 s (IQR: 38-76) in cases and 62 s (IQR: 50-79) in controls (p = 0.058). Cases took longer to progress from > 6 cm to the start of pushing (cases: 02:58 [01:14-04:49], controls: 01:48 [00:51-03:34], p = 0.020) and from pushing to delivery (cases: 00:34 [00:24-01:10], controls: 00:27 [00:13-00:56], p = 0.036).

CONCLUSIONS

Higher contraction frequencies and slower progress towards the end of labour are both independently associated with the risk of moderate-severe HIE. Inter-contraction rest interval duration as measured by external tocography does not provide additional accuracy.

Diagnostic utility of serial circulating placental growth factor levels and uterine artery Doppler waveforms in diagnosing underlying placental diseases in pregnancies at high risk of placental dysfunction

BACKGROUND

Placental pathology assessment following delivery in pregnancies complicated by preeclampsia, fetal growth restriction, abruption, and stillbirth reveals a range of underlying diseases. The most common pathology is maternal vascular malperfusion, characterized by high-resistance uterine artery Doppler waveforms and abnormal expression of circulating maternal angiogenic growth factors. Rare placental diseases (massive perivillous fibrinoid deposition and chronic histiocytic intervillositis) are reported to have high recurrence risks, but their associations with uterine artery Doppler waveforms and angiogenic growth factors are presently ill-defined.

OBJECTIVE

To characterize the patterns of serial placental growth factor measurements and uterine artery Doppler waveform assessments in pregnancies that develop specific types of placental pathology to gain insight into their relationships with the timing of disease onset and pregnancy outcomes.

STUDY DESIGN

A retrospective cohort study conducted between January 2017 and November 2021 included all singleton pregnancies with at least 1 measurement of maternal circulating placental growth factor between 16 and 36 weeks' gestation, delivery at our institution, and placental pathology analysis demonstrating diagnostic features of maternal vascular malperfusion, fetal vascular malperfusion, villitis of unknown etiology, chronic histiocytic intervillositis, or massive perivillous fibrinoid deposition. Profiles of circulating placental growth factor as gestational age advanced were compared between these placental pathologies. Maternal and perinatal outcomes were recorded.

RESULTS

A total of 337 pregnancies from 329 individuals met our inclusion criteria. These comprised placental pathology diagnoses of maternal vascular malperfusion (n=109), fetal vascular malperfusion (n=87), villitis of unknown etiology (n=96), chronic histiocytic intervillositis (n=16), and massive perivillous fibrinoid deposition (n=29). Among patients who developed maternal vascular malperfusion, placental growth factor levels gradually declined as pregnancy progressed (placental growth factor <10th percentile at 16-20 weeks' gestation in 42.9%; 20-24 weeks in 61.9%; 24-28 weeks in 77%; and 28-32 weeks in 81.4%) accompanied by mean uterine artery Doppler pulsatility index >95th percentile in 71.6% cases. Patients who developed either fetal vascular malperfusion or villitis of unknown etiology mostly exhibited normal circulating placental growth factor values in association with normal uterine artery Doppler waveforms (mean [standard deviation] pulsatility index values: fetal vascular malperfusion, 1.14 [0.49]; villitis of unknown etiology, 1.13 [0.45]). Patients who developed either chronic histiocytic intervillositis or massive perivillous fibrinoid deposition exhibited persistently low placental growth factor levels from the early second trimester (placental growth factor <10th centile at 16-20 weeks' gestation in 80% and 77.8%, respectively; 20-24 weeks in 88.9% and 63.6%; 24-28 weeks in 85.7% and 75%), all in combination with normal uterine artery Doppler waveforms (mean pulsatility index >95th centile: chronic histiocytic intervillositis, 25%; massive perivillous fibrinoid deposition, 37.9%). Preeclampsia developed in 83 of 337 (24.6%) patients and was most common in those developing maternal vascular malperfusion (54/109, 49.5%) followed by chronic histiocytic intervillositis (7/16, 43.8%). There were 29 stillbirths in the cohort (maternal vascular malperfusion, n=10 [9.2%]; fetal vascular malperfusion, n=5 [5.7%]; villitis of unknown etiology, n=1 [1.0%]; chronic histiocytic intervillositis, n=7 [43.8%]; massive perivillous fibrinoid deposition, n=6 [20.7%]). Most patients experiencing stillbirth exhibited normal uterine artery Doppler waveforms (21/29, 72.4%) and had nonmaternal vascular malperfusion pathologies (19/29, 65.5%). By contrast, 28 of 29 (96.5%) patients experiencing stillbirth had ≥1 low placental growth factor values before fetal death.

CONCLUSION

Serial circulating maternal placental growth factor tests, in combination with uterine artery Doppler waveform assessments in the second trimester, may indicate the likely underlying type of placental pathology mediating severe adverse perinatal events. This approach has the potential to test disease-specific therapeutic strategies to improve clinical outcomes. Serial placental growth factor testing, compared with uterine artery Doppler studies, identifies a greater proportion of patients destined to have a poor perinatal outcome because diseases other than maternal vascular malperfusion are characterized by normal uteroplacental circulation.

High early pregnancy body mass index is associated with alterations in first- and second-trimester angiogenic biomarkers

BACKGROUND

Obesity is associated with various placenta-mediated adverse pregnancy outcomes, including preeclampsia, preterm birth, and stillbirth. Mechanisms linking obesity with placental dysfunction are not completely understood.

OBJECTIVE

This study aimed to examine the relationship between early pregnancy body mass index and placental angiogenic biomarkers soluble fms-like tyrosine kinase-1, placental growth factor, and the soluble fms-like tyrosine kinase-1-to-placental growth factor ratio.

STUDY DESIGN

We conducted secondary analyses of an existing substudy within a multisite, prospective observational cohort study of nulliparous pregnant women in the United States. First- and second-trimester maternal blood samples, first-trimester body mass index, and demographic, lifestyle, and pregnancy outcomes data were collected. Soluble fms-like tyrosine kinase-1 and placental growth factor concentrations were measured at 6 to 13 and 16 to 22 weeks of gestation for women (cases) who experienced one of several adverse pregnancy outcomes (delivery at <37 weeks of gestation, preeclampsia or eclampsia, birthweight for gestational age <5th percentile, or stillbirth) and for those who had none of those outcomes (controls). We used multivariable mixed-effects linear regression models to estimate the association of body mass index with angiogenic biomarkers at both time points. We evaluated mean change between first- and second-trimester biomarker concentrations using multivariable linear regression models. Lastly, we used logistic regression models to estimate the risk of a high second-trimester soluble fms-like tyrosine kinase-1-to-placental growth factor ratio, using clinically established cutoffs for risk prediction.

RESULTS

Angiogenic biomarker and early pregnancy body mass index data were available for 2363 women (1467 with adverse pregnancy outcomes and 896 controls). High early pregnancy body mass index was associated with consistently lower soluble fms-like tyrosine kinase-1 concentrations across the first and second trimesters of pregnancy. We found lower first-trimester placental growth factor concentrations in the group with class II or III obesity (P<.001) and lower second-trimester placental growth factor concentrations among groups who were overweight, with class I obesity, and class II or III obesity (P<.001). For every unit increase in early pregnancy body mass index, there was a -4.4 pg/mL (95% confidence interval, -3.6 to -5.2) smaller mean increase in placental growth factor concentrations between the first and second trimesters of pregnancy. These differences resulted in significantly lower mean first-trimester soluble fms-like tyrosine kinase-1-to-placental growth factor ratios among groups who were overweight, with class I obesity, and class II or III obesity (P<.05) and in a significantly higher second-trimester soluble fms-like tyrosine kinase-1-to-placental growth factor ratio among the group with class II or III obesity (P<.001), compared with the group with normal body mass index. Each unit of increase in body mass index was associated with a 0.5 (95% confidence interval, 0.3-0.7) greater mean increase in the soluble fms-like tyrosine kinase-1-to-placental growth factor ratio between the first and second trimesters of pregnancy. In stratified analyses, associations between body mass index and angiogenic biomarkers soluble fms-like tyrosine kinase-1 and placental growth factor were similar in nonadverse pregnancy outcome and adverse pregnancy outcome subgroups, whereas associations between body mass index and the soluble fms-like tyrosine kinase-1-to-placental growth factor ratio were attenuated in the subgroups. Participants in the group with class II or III obesity were 3.13 (95% confidence interval, 1.15-8.49) times more likely than participants with normal weight to have a second-trimester ratio of ≥38 in univariate analysis.

CONCLUSION

High early pregnancy body mass index was associated with lower soluble fms-like tyrosine kinase-1 and placental growth factor concentrations across early pregnancy. Maternal body mass was inversely associated with first-trimester soluble fms-like tyrosine kinase-1-to-placental growth factor ratios and positively associated with second-trimester soluble fms-like tyrosine kinase-1-to-placental growth factor ratios, driven by a diminished rise in placental growth factor between the first and second trimesters of pregnancy. Women with class II or III obesity have an increased risk of a high second-trimester soluble fms-like tyrosine kinase-1-to-placental growth factor ratio associated with placental dysfunction.

Associations of maternal angiogenic factors during pregnancy with alterations in cardiac development in childhood at 10 years of age

AIM

To examine whether maternal angiogenic factors in the first half of pregnancy are associated with offspring left and right cardiac development.

METHODS

In a population-based prospective cohort among 2,415 women and their offspring, maternal first and second trimester plasma PlGF and sFlt-1 concentrations were measured. Cardiac MRI was performed in their offspring at 10 years.

RESULTS

Maternal angiogenic factors were not associated with childhood cardiac outcomes in the total population. In children born small-for-their-gestational-age, higher maternal first trimester PlGF concentrations were associated with a lower childhood left ventricular mass  (-0.24 SDS  [95%CI -0.42, -0.05 per SDS increase in maternal PlGF]), whereas higher sFlt-1 concentrations were associated with higher childhood left ventricular mass  (0.22 SDS  [95%CI 0.09, 0.34 per SDS increase in maternal sFlt-1]). Higher second trimester maternal sFlt-1 concentrations were also associated with higher childhood left ventricular mass  (P-value <.05). In preterm born children, higher maternal first and second trimester sFlt-1/PlGF ratio were associated with higher childhood left ventricular mass  (0.30 SDS  [95%CI 0.01, 0.60], 0.22 SDS  [95%CI -0.03, 0.40]) per SDS increase in maternal sFlt-1/PlGF ratio in first and second trimester respectively). No effects on other childhood cardiac outcomes were present within these higher-risk children.

CONCLUSIONS

In a low-risk population, maternal angiogenic factors are not associated with childhood cardiac ventricular structure, and function within the normal range. In children born small for their gestational age or preterm, an imbalance in maternal angiogenic factors in the first half of pregnancy was associated with higher childhood left ventricular mass only.

Adapting obstetric and neonatal services during the COVID-19 pandemic: a scoping review

Background

The provision of care to pregnant persons and neonates must continue through pandemics. To maintain quality of care, while minimizing physical contact during the Severe Acute Respiratory Syndrome-related Coronavirus-2 (SARS-CoV2) pandemic, hospitals and international organizations issued recommendations on maternity and neonatal care delivery and restructuring of clinical and academic services. Early in the pandemic, recommendations relied on expert opinion, and offered a one-size-fits-all set of guidelines. Our aim was to examine these recommendations and provide the rationale and context to guide clinicians, administrators, educators, and researchers, on how to adapt maternity and neonatal services during the pandemic, regardless of jurisdiction.

Method

Our initial database search used Medical subject headings and free-text search terms related to coronavirus infections, pregnancy and neonatology, and summarized relevant recommendations from international society guidelines. Subsequent targeted searches to December 30, 2020, included relevant publications in general medical and obstetric journals, and updated society recommendations.

Results

We identified 846 titles and abstracts, of which 105 English-language publications fulfilled eligibility criteria and were included in our study. A multidisciplinary team representing clinicians from various disciplines, academics, administrators and training program directors critically appraised the literature to collate recommendations by multiple jurisdictions, including a quaternary care Canadian hospital, to provide context and rationale for viable options.

Interpretation

There are different schools of thought regarding effective practices in obstetric and neonatal services. Our critical review presents the rationale to effectively modify services, based on the phase of the pandemic, the prevalence of infection in the population, and resource availability.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04409-4.

Circulating maternal placental growth factor responses to low-molecular-weight heparin in pregnant patients at risk of placental dysfunction

BACKGROUND

Patients at high risk of severe preeclampsia and fetal growth restriction have low circulating levels of placental growth factor and features of maternal vascular malperfusion placental pathology at delivery. Multimodal screening and commencement of aspirin prophylaxis at 11 to 13 weeks' gestation markedly reduces the risk of preterm delivery with preeclampsia. However, the additional role of low-molecular-weight heparin and mechanisms of action remain uncertain. Because low-molecular-weight heparin augments the production and release of placental growth factor in vitro by both placental villi and vascular endothelium, it may be effective to suppress the risk of severe preeclampsia in a niche group of high-risk patients with low circulating placental growth factor in the early second trimester.

OBJECTIVE

This study aimed to define a gestational age-specific reference range for placental growth factor and to test the hypothesis that prophylactic low-molecular-weight heparin administered in the early second trimester may restore deficient circulating placental growth factor levels and thereby prolong pregnancy.

STUDY DESIGN

Centile curves for circulating placental growth factor levels from 12 to 36 weeks' gestation were derived using quantile regression of combined data from a published cohort of 4207 unselected nulliparous patients in Cambridge, United Kingdom, at 4 sampling time points (12, 20, 28, and 36 weeks' gestation) and the White majority (n=531) of a healthy nulliparous cohort in Toronto, Canada, at 16 weeks' gestation using the same test platform. Within a specialty high-risk clinic in Toronto, a niche group of 7 patients with a circulating placental growth factor at the <10th centile in the early second trimester received daily prophylactic low-molecular-weight heparin (enoxaparin; 40 mg subcutaneously) and were followed up until delivery (group 1). Their baseline characteristics, delivery details, and placental pathologies were compared with 5 similar patients who did not receive low-molecular-weight heparin during the observation period (group 2) and further with 21 patients who delivered with severe preeclampsia (group 3) in the same institution.

RESULTS

A gestational age-specific reference range for placental growth factor levels at weekly intervals between 12 and 36 weeks was established for White women with singleton pregnancies. Within group 1, 5 of 7 patients demonstrated a sustained increase in circulating placental growth factor levels, whereas placental growth factor levels did not increase in group 2 or group 3 patients who did not receive low-molecular-weight heparin. Group 1 patients receiving low-molecular-weight heparin therapy exhibited a later gestation at delivery, relative to groups 2 and 3 (36 weeks [33-37] vs 23 weeks [22-26] and 28 weeks [27-31], respectively), and consequently had higher birthweights (1.93 kg [1.1-2.7] vs 0.32 kg [0.19-0.39] and 0.73 kg [0.52-1.03], respectively). The incidence of stillbirth was lowest in group 1 (14% [1 of 7]), relative to groups 2 and 3 (80% [4 of 5] and 29% [6 of 21], respectively). Maternal vascular malperfusion was the most common placental pathology found in association with abnormal uterine artery Doppler.

CONCLUSION

In patients at high risk of a serious adverse pregnancy outcome owing to placental disease, the addition of low-molecular-weight heparin to aspirin prophylaxis in the early second trimester may restore deficient circulating placental growth factor to mediate an improved perinatal outcome. These data support the implementation of a multicenter pilot randomized control trial where patients are recruited primarily based on the assessment of placental function in the early second trimester.

Toward personalized management of chronic hypertension in pregnancy

Chronic hypertension complicates 1% to 2% of pregnancies, and it is increasingly common. Women with chronic hypertension are an easily recognized group who are in touch with a wide variety of healthcare providers before, during, and after pregnancy, mandating that chronic hypertension in pregnancy be within the scope of many practitioners. We reviewed recent data on management to inform current care and future research. This study is a narrative review of published literature. Compared with normotensive women, women with chronic hypertension are at an increased risk of maternal and perinatal complications. Women with chronic hypertension who wish to be involved in their care can do by measuring blood pressure at home. Accurate devices for home blood pressure monitoring are now readily available. The diagnostic criteria for superimposed preeclampsia remain problematic because most guidelines continue to include deteriorating blood pressure control in the definition. It has not been established how angiogenic markers may aid in confirmation of the diagnosis of superimposed preeclampsia when suspected, over and above information provided by routinely available clinical data and laboratory results. Although chronic hypertension is a strong risk factor for preeclampsia, and aspirin decreases preeclampsia risk, the effectiveness specifically among women with chronic hypertension has been questioned. It is unclear whether calcium has an independent effect in preeclampsia prevention in such women. Treating hypertension with antihypertensive therapy halves the risk of progression to severe hypertension, thrombocytopenia, and elevated liver enzymes, but a reduction in preeclampsia or serious maternal complications has not been observed; however, the lack of evidence for the latter is possibly owing to few events. In addition, treating chronic hypertension neither reduces nor increases fetal or newborn death or morbidity, regardless of the gestational age at which the antihypertensive treatment is started. Antihypertensive agents are not teratogenic, but there may be an increase in malformations associated with chronic hypertension itself. At present, blood pressure treatment targets used in clinics are the same as those used at home, although blood pressure values tend to be inconsistently lower at home among women with hypertension. Although starting all women on the same antihypertensive medication is usually effective in reducing blood pressure, it remains unclear whether there is an optimal agent for such an approach or how best to use combinations of antihypertensive medications. An alternative approach is to individualize care, using maternal characteristics and blood pressure features beyond blood pressure level (eg, variability) that are of prognostic value. Outcomes may be improved by timed birth between 38 0/7 and 39 6/7 weeks' gestation based on observational literature; of note, confirmatory trial evidence is pending. Postnatal care is facilitated by the acceptability of most antihypertensives (including angiotensin-converting enzymes inhibitors) for use in breastfeeding. The evidence base to guide the care of pregnant women with chronic hypertension is growing and aligning with international guidelines. Addressing outstanding research questions would inform personalized care of chronic hypertension in pregnancy.

Identification of key genes in pathogenesis of placental insufficiency intrauterine growth restriction

Background

Intrauterine growth restriction (IUGR) is defined as a fetus that fails to achieve its genetically determined growth potential. The exact molecular mechanisms of placental insufficiency IUGR pathogenesis are a little known. Our goal was to identify key genes and gene co-expression modules related to placental insufficiency IUGR.

Methods

We used weighted gene co-expression network analysis (WGCNA) and protein-protein interaction (PPI) network analysis to examine the IUGR dataset GSE114691 from NCBI Gene Expression Omnibus. Core modules and hub nodes of the protein-protein interaction network were identified. A gene network was constructed and genes were classified by WGCNA into different modules. The validation of potential key genes was carried out using additional datasets (GSE12216 and GSE24129).

Results

We identified in GSE114691 539 down regulated genes and 751 up regulated genes in placental tissues characteristic of placental insufficiency IUGR compared with non-IUGR, and defined 76 genes as hub nodes in the protein-protein interaction network. Genes in the key modules of the WGCNA network were most closely associated with placental insufficiency IUGR and significantly enriched in biological process such as cellular metabolic process and macromolecule metabolic process. We identified as key genes TGFB1, LEP, ENG, ITGA5, STAT5A, LYN, GATA3, FPR1, TGFB2, CEBPB, KLF4, FLT1, and PNPLA2. The RNA expression levels of ENG and LEP, as biomarkers, were validated.

Conclusion

A holistic gene expression profile of placental insufficiency IUGR has been generated and the key genes ENG and LEP has potential to serve as circulating diagnosis biomarkers and therapeutic targets for placental insufficiency IUGR.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04399-3.

Metabolic-endocrine disruption due to preterm birth impacts growth, body composition, and neonatal outcome

Despite optimized nutrition, preterm-born infants grow slowly and tend to over-accrete body fat. We hypothesize that the premature dissociation of the maternal-placental-fetal unit disrupts the maintenance of physiological endocrine function in the fetus, which has severe consequences for postnatal development. This review highlights the endocrine interactions of the maternal-placental-fetal unit and the early perinatal period in both preterm and term infants. We report on hormonal levels (including tissue, thyroid, adrenal, pancreatic, pituitary, and placental hormones) and nutritional supply and their impact on infant body composition. The data suggest that the premature dissociation of the maternal-placental-fetal unit leads to a clinical picture similar to panhypopituitarism. Further, we describe how the premature withdrawal of the maternal-placental unit, neonatal morbidities, and perinatal stress can cause differences in the levels of growth-promoting hormones, particularly insulin-like growth factors (IGF). In combination with the endocrine disruption that occurs following dissociation of the maternal-placental-fetal unit, the premature adaptation to the extrauterine environment leads to early and fast accretion of fat mass in an immature body. In addition, we report on interventional studies that have aimed to compensate for hormonal deficiencies in infants born preterm through IGF therapy, resulting in improved neonatal morbidity and growth. IMPACT: Preterm birth prematurely dissociates the maternal-placental-fetal unit and disrupts the metabolic-endocrine maintenance of the immature fetus with serious consequences for growth, body composition, and neonatal outcomes. The preterm metabolic-endocrine disruption induces symptoms resembling anterior pituitary failure (panhypopituitarism) with low levels of IGF-1, excessive postnatal fat mass accretion, poor longitudinal growth, and failure to thrive. Appropriate gestational age-adapted nutrition alone seems insufficient for the achievement of optimal growth of preterm infants. Preliminary results from interventional studies show promising effects of early IGF-1 supplementation on postnatal development and neonatal outcomes.

Placental adaptations in a nonhuman primate model of gestational protein restriction

We previously demonstrated decreased placental perfusion, reduced amniotic fluid protein content, and increased pregnancy loss in a nonhuman primate model of gestational protein restriction. Here, our objective was to link these detrimental findings with a functional placental assessment. As blood flow is critical to maternal-fetal exchange, we hypothesized that a protein-restricted diet would impair placental taurine uptake. Pregnant rhesus macaques were maintained on either control chow (CON, n = 5), a 33% protein-restricted diet (PR33, n = 5), or a 50% PR diet (PR50, n = 5) prior to and throughout pregnancy. Animals were delivered on gestational day 135 (G135; term is G168). Taurine activity was determined in fresh placental villous explants. Taurine transporter (TauT) protein expression, placental growth factor (PLGF), and insulin-like growth factor (IGF)-1 and IGF-2 protein concentrations were measured, and histological assessment was performed. Fetal body weights and placental weights were comparable between all three groups at G135. Placental taurine uptake was decreased in PR33- and PR50-fed animals compared to CON, yet TauT expression was unchanged across groups. PLGF was significantly increased in PR50 vs. CON, with no change in IGF-1 or IGF-2 expression in placental homogenate from PR-fed animals. Accelerated villous maturation was observed in all PR50 cases, three of five PR33, and was absent in CON. We demonstrate conserved fetal growth, despite a decrease in placental taurine uptake. Increased expression of PLGF and expansion of the syncytiotrophoblast surface area in the severely protein-restricted animals suggest a compensatory mechanism by the placenta to maintain fetal growth.

Maternal alpha-1-antitrypsin as a noval marker for growth restriction in pre-eclampsia

AIM

To verify the role of maternal serum levels of alpha-1-antitrypsin (AAT), an acute-phase inflammatory protein, as a marker for distinguishing between fetal growth restriction (FGR) and normal birth weight in pre-eclamptic women. We correlate serum AAT levels to the essential feto-maternal parameters for an earlier and cost-benefit diagnostic method, thus distinguishing between FGR and normal birth weight in pre-eclamptic women.

METHODS

An observational study conducted at the University hospital recruited 100 pregnant women in 32/34 weeks of a singleton single tone pregnancy; all were pre-eclampsia cases. All were tested by laboratory and ultrasound examination. Two sets of data were collected; one is maternal parameters such as blood pressure (BP), maternal serum AAT mean platelet volume (MPV), platelet distribution width (PDW), and serum uric acid levels, and the other is fetal parameters such as amniotic fluid index (AFI), fetal weight centile and estimated fetal weight.

RESULTS

A strong negative correlation proved between serum levels of AAT and all study variables except fetal weight (systolic BP, diastolic BP, MPV, PDW, serum uric acid, fetal weight percentile, and AFI) with a correlation coefficient of; -0.95, -0.95, -0.85, -0.93, -0.91, -0.94, and -0.93 respectively. The cut-off value for AAT 0.013 mg/ml showed the highest sensitivity and specificity as a diagnostic marker for FGR. Area under the curve was 0.99.

CONCLUSIONS

Negative correlations between maternal serum AAT and fetal parameters used to assess FGR were confirmed, suggesting that AAT is closely related to the pathophysiology of FGR among pre-eclamptic patients and may serve as a helpful tool in distinguishing between FGR and normal birth weight babies, pending further validation in feto-maternal outcomes.

S100B in maternal circulation of pregnancies complicated by FGR and brain sparing

OBJECTIVE

To determine whether the presence of brain sparing in fetal growth restricted (FGR) fetuses involves elevation of the cerebral injury biomarker S100B in maternal circulation.

METHODS

We included 63 women with suspected small for gestational age (SGA) fetuses between 24 and 35 +6/7 weeks of gestation. Maternal plasma angiogenic factors measurements and sonographic evaluation were performed at recruitment. Next, we subdivided our SGA cohort into three groups: SGA fetuses, FGR fetuses without brain-sparing, and FGR fetuses with brain-sparing (FGR-BS). Serum S100B concentration was calculated as S100B µg/L, S100B MoM, and the ratio S100B/ estimated fetal weight (EFW). We also report one case of S100B concentration surge in maternal serum following the diagnosis of fetal intraventricular hemorrhage (IVH).

RESULTS

The FGR-BS group had higher maternal S100B µg/L (p < 0.01, p < 0.05, respectively), S100B MoM (p < 0.001, p < 0.001, respectively), and S100B/EFW (p < 0.001, p < 0.01, respectively), compared to the SGA and FGR groups. In the case report, maternal serum S100B concentrations were 0.0346 µg/L before, and 0.0874 µg/L after IVH occurrence.

CONCLUSIONS

S100B concentration in maternal serum increased in pregnancies complicated by FGR and brain sparing. These results may substantiate in-utero cerebral injury and may explain the adverse neurocognitive outcomes reported for this group.

First trimester placental growth factor in maternal blood and placenta related disorders

OBJECTIVE

To describe and compare the placental growth factor levels at first trimester in patients that developed preeclampsia, gestational hypertension, IUGR and in those patients without impaired placentation diseases.

METHODS

Observational study based on a prospective cohort of 422 pregnant women. PlGF values were compared between the different groups (preeclampsia, intrauterine growth restriction (IUGR), gestational hypertension or normal group-patients without impaired placentation diseases).

RESULTS

The 85.3% (n = 360, 95% CI = 81.9-88.7) had a normal pregnancy, 7.6% (n = 32, 95% CI = 5.1-10.1) had preeclampsia, 3.8% (n = 16, 95% CI = 2.0-5.6) had IUGR and 3.3% (n = 14, 95% CI = 1.6-5.0) had gestational hypertension. The median level of PlGF for preeclampsia (0.76) and IUGR (0.75) were lower than gestational hypertension (0.82) and normal group (1.02). The groups of preeclampsia >34 weeks (0.76), preeclampsia <37 weeks (0.73), and preeclampsia ≥37 weeks (0.77), were significantly lower than the normal group. The sensitivity and specificity of PlGF for impaired placentation diseases is 65% and 64.9%, respectively.

CONCLUSION

It was found in this study that PlGF has significantly lower levels in gestational hypertension than normal pregnancies, in concordance with the other impaired placentation diseases. Additionally, a better comparison of the PlGF values was obtained when separating early onset of preeclampsia <37 weeks and late-onset of preeclampsia 37≥ weeks of gestations.

Fetal Growth Restriction: Does an Integrated Maternal Hemodynamic-Placental Model Fit Better?

In recent years, a growing interest has arisen regarding the possible relationship between adverse pregnancy outcomes (APOs) and inadequate maternal hemodynamic adaptations to the pregnancy. A possible association between "placental syndromes," such as preeclampsia (PE) and fetal growth restriction (FGR), and subsequent maternal cardiovascular diseases (CVD) later in life has been reported. The two subtypes of FGR show different pathogenetic and clinical features. Defective placentation, due to a poor trophoblastic invasion of the maternal spiral arteries, is believed to play a central role in the pathogenesis of early-onset PE and FGR. Since placental functioning is dependent on the maternal cardiovascular system, a pre-existent or subsequent cardiovascular impairment may play a key role in the pathogenesis of early-onset FGR. Late FGR does not seem to be determined by a primary abnormal placentation in the first trimester. The pathological pathway of late-onset FGR may be due to a primary maternal cardiovascular maladaptation: CV system shows a flat profile and remains similar to those of non-pregnant women. Since the second trimester, when the placenta is already developed and increases its functional request, a hypovolemic state could lead to placental hypoperfusion and to an altered maturation of the placental villous tree and therefore to an altered fetal growth. Thus, this review focalizes on the possible relationship between maternal cardiac function and placentation in the development of both early and late-onset FGR. A better understanding of maternal hemodynamics in pregnancies complicated by FGR could bring various benefits in clinical practice, improving screening and therapeutic tools.

Circulating syndecan-1 is reduced in pregnancies with poor fetal growth and its secretion regulated by matrix metalloproteinases and the mitochondria

Fetal growth restriction is a leading cause of stillbirth that often remains undetected during pregnancy. Identifying novel biomarkers may improve detection of pregnancies at risk. This study aimed to assess syndecan-1 as a biomarker for small for gestational age (SGA) or fetal growth restricted (FGR) pregnancies and determine its molecular regulation. Circulating maternal syndecan-1 was measured in several cohorts; a large prospective cohort collected around 36 weeks’ gestation (n = 1206), a case control study from the Manchester Antenatal Vascular service (285 women sampled at 24–34 weeks’ gestation); two prospective cohorts collected on the day of delivery (36 + 3–41 + 3 weeks’ gestation, n = 562 and n = 405 respectively) and a cohort who delivered for preterm FGR (< 34 weeks). Circulating syndecan-1 was consistently reduced in women destined to deliver growth restricted infants and those delivering for preterm disease. Syndecan-1 secretion was reduced by hypoxia, and its loss impaired proliferation. Matrix metalloproteinases and mitochondrial electron transport chain inhibitors significantly reduced syndecan-1 secretion, an effect that was rescued by coadministration of succinate, a mitochondrial electron transport chain activator. In conclusion, circulating syndecan-1 is reduced among cases of term and preterm growth restriction and has potential for inclusion in multi-marker algorithms to improve detection of poorly grown fetuses.

The association between placenta-associated circulating biomarkers and composite adverse delivery outcome of a likely placental cause in healthy post-date pregnancies

INTRODUCTION

Post-date pregnancies have an increased risk of adverse delivery outcome. Our aim was to explore the association between placenta-associated circulating biomarkers and composite adverse delivery outcome of a likely placental cause in clinically healthy post-date pregnancies.

MATERIAL AND METHODS

Women with healthy singleton post-date pregnancies between 40⁺² and 42⁺²  weeks of gestation were recruited to this prospective, observational study conducted at Oslo University Hospital, Norway (NCT03100084). Placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) were measured in the maternal serum samples closest to delivery. The composite adverse delivery outcome included fetal acidemia, low Apgar score (<4 at 1 min or <7 at 5 min), asphyxia, fetal death, assisted ventilation for more than 6 h, meconium aspiration, hypoxic-ischemic encephalopathy, therapeutic hypothermia, operative delivery due to fetal distress, or pathological placental histology findings. Two study-independent senior consultant obstetricians blinded to biomarker results concluded, based on clinical expert opinion, whether the adverse delivery outcomes were most likely associated with placental dysfunction ("likely placental cause") or not. Means were compared using one-way analysis of variance and Bonferroni corrected pairwise comparisons between groups. Receiver operating characteristic (ROC) curves assessed the predictive ability of PlGF, sFlt-1/PlGF ratio, and PlGF <10th centile after adjustment for gestational age at blood sampling.

RESULTS

Of 501 pregnancies reviewed for predefined adverse delivery outcomes and for a likely placental cause, 468 were healthy pregnancies and subsequently assigned to either the "uncomplicated" (no adverse outcome, n = 359), "intermediate" (non-placental cause/undetermined, n = 90), or "complicated" (likely placental cause, n = 19) group. There was a significant difference in mean PlGF and sFlt-1/PlGF ratio between the "complicated", "intermediate", and "uncomplicated" groups (108, 185, and 179 pg/mL, p = 0.001; and 48.3, 23.4, and 24.6, p = 0.002, respectively). There was a higher proportion of PlGF concentration <10th centile in the "complicated" group compared with the "intermediate" and "uncomplicated" groups (42.1% vs. 11.1% and 9.5%, p = 0.001). The largest area under the ROC curve for predicting "complicated" outcome was achieved by PlGF concentration and gestational age at blood sampling (0.76; 95% CI 0.65-0.86).

CONCLUSIONS

In clinically healthy post-date pregnancies, an antiangiogenic pre-delivery profile (lower PlGF level and higher sFlt-1/PlGF ratio) was associated with composite adverse delivery outcome of a likely placental cause.

Association of Elevated Maternal Serum Total Bile Acids With Low Birth Weight and Intrauterine Fetal Growth Restriction

IMPORTANCE

Bile acids play essential roles in metabolic modulation. Excessive serum total bile acid (sTBA) levels during pregnancy are associated with adverse perinatal outcomes; however, their association with the risk of intrauterine growth restriction (IUGR) remains unclear.

OBJECTIVE

To investigate the association between maternal sTBA concentration during pregnancy and the risk of IUGR.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study included pregnant individuals who delivered live singleton neonates and had regular antenatal examination records available at a hospital-based center in Shanghai, China, from 2014 to 2018. Data were analyzed from July to November 2020.

EXPOSURES

Maternal sTBA concentration during pregnancy.

MAIN OUTCOMES AND MEASURES

Fetal birth weight and probability of low birth weight (LBW) and IUGR.

RESULTS

This study included 68 245 singleton pregnancies with live births for analysis. The mean (SD) age of the pregnant individuals was 30.5 (3.8) years, 67 168 patients (98.4%) were Han, and 50 155 (73.5%) were nulliparous. Nonlinear regression models suggested that there was an inverted J-shaped association between maternal sTBA level during pregnancy and fetal birth weight, with a steep decrease in birth weight at high sTBA levels (estimated mean [SE] birth weight for sTBA of 40.8 ug/mL, 2879 [39.9] g) and greater birth weights at lower sTBA levels (estimated mean [SE] birth weight for sTBA 0.4 μg/mL, 3290 [3.9] g; and for 4.1 μg/mL, 3334 [1.6] g). Lower birth weight and a higher incidence of IUGR were observed in patients with gestational hypercholanemia (sTBA ≥4.08 μg/mL) compared with those without gestational hypercholanemia (birth weight: estimated adjusted mean [SE], 3309 [3.32] vs 3338 [0.80] g; P = .005; incidence of IUGR: 62 of 4467 [1.4%] vs 312 of 63 778 [0.5%]; P < .001). Moreover, compared with patients with sTBA concentrations of less than 4.08 μg/mL, those with gestational hypercholanemia had an increased risk of LBW (adjusted odds ratio [aOR], 1.29; 95% CI, 1.09-1.53) and IUGR (aOR, 2.18; 95% CI, 1.62-2.91). In addition, there was an additive interaction between hypertensive disorders in pregnancy (HDP) and hypercholanemia on LBW and IUGR risk. The highest risks of LBW and IUGR were found in pregnant individuals with both HDP and hypercholanemia compared with those with normotensive pregnancies with sTBA concentrations less than 4.08 μg/mL (LBW: aOR, 9.13; 95% CI, 6.88-12.12; IUGR: aOR, 19.14; 95% CI, 12.09-30.28).

CONCLUSIONS AND RELEVANCE

This study found that gestational hypercholanemia was associated with an increased risk of LBW and IUGR, especially in pregnant individuals with HDP. Therefore, it would be meaningful to monitor sTBA concentration during the follow-up of pregnancies with potential IUGR.