Angiogenic growth factor levels in maternal and fetal blood: correlation with Doppler ultrasound parameters in pregnancies complicated by pre-eclampsia and intrauterine growth restriction

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..

Angiogenic and vasoactive proteins in the maternal-fetal interface in healthy pregnancies and preeclampsia

BACKGROUND

Preeclampsia is characterized by maternal endothelial activation and placental dysfunction. Imbalance in maternal angiogenic and vasoactive factors has been linked to the pathophysiology. The contribution of the placenta as a source of these factors remains unclear. Furthermore, little is known about fetal angiogenic and vasoactive proteins and the relation between maternal and fetal levels.

OBJECTIVE

We describe placental growth factor, soluble Fms-like tyrosine kinase 1, soluble endoglin, and endothelin 1-3 in 5 vessels in healthy pregnancies, early- and late-onset preeclampsia. Specifically, we aimed to (1) compare protein abundance in vessels at the maternal-fetal interface between early- and late-onset preeclampsia, and healthy pregnancies, (2) describe placental uptake and release of proteins, and (3) describe protein abundance in the maternal vs fetal circulations.

STUDY DESIGN

Samples were collected from the maternal radial artery, uterine vein and antecubital vein, and fetal umbilical vein and artery in 75 healthy and 37 preeclamptic mother-fetus pairs (including 19 early-onset preeclampsia and 18 late-onset preeclampsia), during scheduled cesarean delivery. This method allows estimation of placental release and uptake of proteins by calculation of venoarterial differences on each side of the placenta. The microarray-based SomaScan assay quantified the proteins.

RESULTS

The abundance of soluble Fms-like tyrosine kinase 1 and endothelin 1 was higher in the maternal vessels in preeclampsia than in healthy pregnancies, with the highest abundance in early-onset preeclampsia. Placental growth factor was lower in the maternal vessels in early-onset preeclampsia than in both healthy and late-onset preeclampsia. Maternal endothelin 2 was higher in preeclampsia, with late-onset preeclampsia having the highest abundance. Our model confirmed placental release of placental growth factor and soluble Fms-like tyrosine kinase 1 to the maternal circulation in all groups. The placenta released soluble Fms-like tyrosine kinase 1 into the fetal circulation in healthy and late-onset preeclampsia pregnancies. Fetal endothelin 1 and soluble Fms-like tyrosine kinase 1 were higher in early-onset preeclampsia, whereas soluble endoglin and endothelin 3 were lower in both preeclampsia groups than healthy controls. Across groups, abundances of placental growth factor, soluble Fms-like tyrosine kinase 1, and endothelin 3 were higher in the maternal artery than the fetal umbilical vein, whereas endothelin 2 was lower.

CONCLUSION

An increasing abundance of maternal soluble Fms-like tyrosine kinase 1 and endothelin 1 across the groups healthy, late-onset preeclampsia and early-onset combined with a positive correlation may suggest that these proteins are associated with the pathophysiology and severity of the disease. Elevated endothelin 1 in the fetal circulation in early-onset preeclampsia represents a novel finding. The long-term effects of altered protein abundance in preeclampsia on fetal development and health remain unknown. Further investigation of these proteins' involvement in the pathophysiology and as treatment targets is warranted.

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.

Similar Pro- and Antiangiogenic Profiles Close to Delivery in Different Clinical Presentations of Two Pregnancy Syndromes: Preeclampsia and Fetal Growth Restriction

The purpose of this study was to evaluate serum levels of anti- and pro-angiogenic substances measured using enzyme-linked immunosorbent assays and their ratios in pregnancies complicated by different clinical subsets of placental ischemic syndrome: preeclampsia and/or fetal growth restriction. A prospective case-control study was performed consisting of 77 singleton pregnancies complicated by preeclampsia, preeclampsia with concurrent fetal growth restriction (FGR), and isolated normotensive FGR pairwise matched by gestational age with healthy pregnancies. The entire study cohort was analyzed with respect to adverse pregnancy outcomes that occurred. In all investigated subgroups, placental growth factor (PlGF) was lower and soluble endoglin (sEng), the soluble fms-like tyrosine kinase-1-sFlt-1/PlGF and sFlt-1*sEng/PlGF ratios were higher than in the control group. The differences were most strongly pronounced in the PE with concurrent FGR group and in the sFlt-1/PlGF ratio. The highest sFlt-1 values in preeclamptic patients suggest that this substance may be responsible for reaching the threshold needed for PE to develop as a maternal manifestation of ischemic placental disease. The FGR is characterized by an elevated maternal sFlt-1/PlGF ratio, which boosts at the moment of indicated delivery due to fetal risk. We concluded that angiogenic imbalance is reflective of placental disease regardless of its clinical manifestation in the mother, and may be used as support for the diagnosis and prognosis of FGR.

Toward a new taxonomy of obstetrical disease: improved performance of maternal blood biomarkers for the great obstetrical syndromes when classified according to placental pathology

BACKGROUND

The major challenge for obstetrics is the prediction and prevention of the great obstetrical syndromes. We propose that defining obstetrical diseases by the combination of clinical presentation and disease mechanisms as inferred by placental pathology will aid in the discovery of biomarkers and add specificity to those already known.

OBJECTIVE

To describe the longitudinal profile of placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1), and the PlGF/sFlt-1 ratio throughout gestation, and to determine whether the association between abnormal biomarker profiles and obstetrical syndromes is strengthened by information derived from placental examination, eg, the presence or absence of placental lesions of maternal vascular malperfusion.

STUDY DESIGN

This retrospective case cohort study was based on a parent cohort of 4006 pregnant women enrolled prospectively. The case cohort of 1499 pregnant women included 1000 randomly selected patients from the parent cohort and all additional patients with obstetrical syndromes from the parent cohort. Pregnant women were classified into six groups: 1) term delivery without pregnancy complications (n=540; control); 2) preterm labor and delivery (n=203); 3) preterm premature rupture of the membranes (n=112); 4) preeclampsia (n=230); 5) small-for-gestational-age neonate (n=334); and 6) other pregnancy complications (n=182). Maternal plasma concentrations of PlGF and sFlt-1 were determined by enzyme-linked immunosorbent assays in 7560 longitudinal samples. Placental pathologists, masked to clinical outcomes, diagnosed the presence or absence of placental lesions of maternal vascular malperfusion. Comparisons between mean biomarker concentrations in cases and controls were performed by utilizing longitudinal generalized additive models. Comparisons were made between controls and each obstetrical syndrome with and without subclassifying cases according to the presence or absence of placental lesions of maternal vascular malperfusion.

RESULTS

1) When obstetrical syndromes are classified based on the presence or absence of placental lesions of maternal vascular malperfusion, significant differences in the mean plasma concentrations of PlGF, sFlt-1, and the PlGF/sFlt-1 ratio between cases and controls emerge earlier in gestation; 2) the strength of association between an abnormal PlGF/sFlt-1 ratio and the occurrence of obstetrical syndromes increases when placental lesions of maternal vascular malperfusion are present (adjusted odds ratio [aOR], 13.6 vs 6.7 for preeclampsia; aOR, 8.1 vs 4.4 for small-for-gestational-age neonates; aOR, 5.5 vs 2.1 for preterm premature rupture of the membranes; and aOR, 3.3 vs 2.1 for preterm labor (all P<0.05); and 3) the PlGF/sFlt-1 ratio at 28 to 32 weeks of gestation is abnormal in patients who subsequently delivered due to preterm labor with intact membranes and in those with preterm premature rupture of the membranes if both groups have placental lesions of maternal vascular malperfusion. Such association is not significant in patients with these obstetrical syndromes who do not have placental lesions.

CONCLUSION

Classification of obstetrical syndromes according to the presence or absence of placental lesions of maternal vascular malperfusion allows biomarkers to be informative earlier in gestation and enhances the strength of association between biomarkers and clinical outcomes. We propose that a new taxonomy of obstetrical disorders informed by placental pathology will facilitate the discovery and implementation of biomarkers as well as the prediction and prevention of such disorders.

Angiogenic factors for planning fetal surveillance in fetal growth restriction and small-for-gestational-age fetuses: A prospective observational study

OBJECTIVE

The aim of this study was to assess the added value of the soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) ratio for adjusting the periodicity of ultrasound examinations in early-onset fetal growth restriction (FGR) and small for gestational age (SGA).

DESIGN

A prospective, observational study.

SETTING

Tertiary referral hospital.

POPULATION

One hundred and thirty-four single pregnancies with ultrasonographic estimated fetal weight (EFW) below the 10th centile between 20+0 and 31+6  weeks of gestation with antegrade umbilical artery flow.

METHODS

The time from Doppler and sFlt-1/PlGF assessment to delivery was recorded and classified into four ranges: <1, <2, <3 and <4 weeks.

MAIN OUTCOME MEASURES

Sensitivity (Sn), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) of sFlt-1/PlGF values to predict the time to delivery.

RESULTS

In the SGA cohort, the NPV calculated for an sFlt-1/PlGF cut-off value of 38 was 100% for delivery before 3 weeks, and 98% for delivery before 4 weeks after diagnosis (95% CI 0.89-1.00). In the FGR cohort, the NPV calculated for an sFlt-1/PlGF cut-off value of 38 was 100% for delivery before 2 weeks after diagnosis (95% CI 0.92-1.00). By contrast, more than 50% of cases with an sFlt-1/PlGF value of >85 required an elective delivery before 1 week.

CONCLUSIONS

sFlt-1/PlGF values in early-onset SGA and FGR are predictive of the time to delivery and could be used for planning fetal surveillance, by reducing the frequency of ultrasound in cases with sFlt-1/PlGF < 38 and by providing closer follow-up in cases with sFlt-1/PlGF >85.

TWEETABLE ABSTRACT

sFlt-1/PlGF values in early-onset SGA/FGR could be used in addition to Doppler for planning fetal surveillance.

Biophysical Markers of Suspected Preeclampsia, Fetal Growth Restriction and the Two Combined—How Accurate They Are?

Objectives—To conduct a secondary analysis of prediction accuracy of biophysical markers for suspected Preeclampsia (PE), Fetal Growth Restriction (FGR) and the two combined near delivery in a Slovenian cohort. Methods—This was a secondary analysis of a database of a total 125 Slovenian pregnant women attending a high-risk pregnancy clinic due to suspected PE (n = 31), FGR (n = 16) and PE + FGR (n = 42) from 28–39 weeks gestation and their corresponding term (n = 21) and preterm (PTD, n = 15) controls. Data for Mean Arterial blood Pressure (MAP) and Uterine artery pulsatility index (UtA PI) estimated by Doppler sonography were extracted from the database of patients who were tested at admission to the high-risk clinic with the suspected complications. The reactive hyperemia index (RHI), and the Augmentation Index (AIX%) were extracted from the patient database using measured values obtained with the assistance of the Endo PAT, a device set to measure the signal of the peripheral arterial tone (PAT) from the blood vessels endothelium. Linear regression coefficients, Box and Whisker plots, Area under the Curve (AUC) of receiver Operation Characteristic (ROC) curves, and multiple regression were used to assess the marker accuracy using detection rate (DR) and false-positive rate (FPR) and previously reported cut-offs for estimating the positive and negative predictive value (NPV and PPV). The SPSS non-parametric statistics (Kruskal Wallis and Mann–Whitney) and Spearman’s regression coefficient were used to assess marker accuracy; p < 0.05 was considered significant. Results—MAP values reached diagnostic accuracy (AUC = 1.00, DR = 100%) for early PE cases delivered < 34, whereas UtA Doppler PI values yielded such results for early FGR < 34 weeks and the two combined reached such accuracy for PE + FGR. To reach diagnostic accuracy for all cases of the complications, the Endo PAT markers with values for MAP and UtA Doppler PI were required for cases near delivery. Multiple regression analyses showed added value for advanced maternal age and gestational week in risk assessment for all cases of PE, FGR, and PE + FGR. Spearman’s regression coefficient yielded r > 0.6 for UtA Doppler PI over GA for PE and FGR, whereas for RHI over BMI, the regression coefficient was r > 0.5 (p < 0.001 for each). Very high correlations were also found between UtA Doppler PI and sFlt-1/PlGF or PlGF (r = −0.495, p < 0.001), especially in cases of FGR. Conclusion—The classical biophysical markers MAP and UtA Doppler PI provided diagnostic accuracy for PE and FGR < 34 wks gestation. A multiple biophysical marker analysis was required to reach diagnostic accuracy for all cases of these complications. The UtA Doppler PI and maternal serum sFlt-1/PlGF or PlGF were equally accurate for early cases to enable the choice of the markers for the clinical use according to the more accessible method.

Endothelial dysfunction in preterm infants: The hidden legacy of uteroplacental pathologies

Millions of infants are born prematurely every year worldwide. Prematurity, particularly at lower gestational ages, is associated with high mortality and morbidity and is a significant global health burden. Pregnancy complications and preterm birth syndrome strongly impact neonatal clinical phenotypes and outcomes. The vascular endothelium is a pivotal regulator of fetal growth and development. In recent years, the key role of uteroplacental pathologies impairing endothelial homeostasis is emerging. Conditions leading to very and extremely preterm birth can be classified into two main pathophysiological patterns or endotypes: infection/inflammation and dysfunctional placentation. The first is frequently related to chorioamnionitis, whereas the second is commonly associated with hypertensive disorders of pregnancy and fetal growth restriction. The nature, timing, and extent of prenatal noxa may alter fetal and neonatal endothelial phenotype and functions. Changes in the luminal surface, oxidative stress, growth factors imbalance, and dysregulation of permeability and vascular tone are the leading causes of endothelial dysfunction in preterm infants. However, the available evidence regarding endothelial physiology and damage is limited in neonates compared to adults. Herein, we discuss the current knowledge on endothelial dysfunction in the infectious/inflammatory and dysfunctional placentation endotypes of prematurity, summarizing their molecular features, available biomarkers, and clinical impact. Furthermore, knowledge gaps, shadows, and future research perspectives are highlighted.

Maternal plasma soluble neuropilin-1 is downregulated in fetal growth restriction complicated by abnormal umbilical artery Doppler: a pilot study

OBJECTIVES

Placental expression of neuropilin-1 (NRP1), a proangiogenic member of the vascular endothelial growth factor receptor family involved in sprouting angiogenesis, was recently discovered to be downregulated in pregnancies with fetal growth restriction (FGR) and abnormal umbilical artery (UA) Doppler. Soluble NRP1 (sNRP1) is an antagonist to NRP1; however, little is known about its role in normal and FGR pregnancies. This study tested the hypotheses that, first, sNRP1 would be detectable in maternal circulation and, second, its concentration would be upregulated in FGR pregnancies compared to those with normal fetal growth and this would correlate with the severity of the disease as assessed by UA Doppler.

METHODS

This was a prospective case-control pilot study of 40 singleton pregnancies (20 FGR cases and 20 uncomplicated controls) between 24 + 0 and 40 + 0 weeks' gestation followed in an academic perinatal center from January 2015 to May 2017. FGR was defined as an ultrasound-estimated fetal weight < 10^th percentile for gestational age. The control group was matched to the FGR group for maternal age and gestational age at assessment. Fetal ultrasound biometry and UA Doppler were performed using standard protocols. Maternal plasma sNRP1 measurements were performed using a commercially available ELISA.

RESULTS

Contrary to the study hypothesis, maternal plasma sNRP1 levels were significantly decreased in FGR pregnancies as compared to those with normal fetal growth (137.4 ± 44.8 pg/mL vs 166.7 ± 36.9 pg/mL; P = 0.03). However, there was no significant difference in sNRP1 concentration between the control group and FGR pregnancies that had normal UA Doppler. Plasma sNRP1 was downregulated in FGR pregnancies with elevated UA systolic/diastolic ratio (P = 0.023) and those with UA absent or reversed end-diastolic flow (P = 0.005) in comparison to FGR pregnancies with normal UA Doppler. This suggests that biometrically small fetuses without hemodynamic compromise are small-for-gestational age rather than FGR.

CONCLUSIONS

This study demonstrated a significant decrease in maternal plasma sNRP1 concentration in growth-restricted pregnancies with fetoplacental circulatory compromise. These findings suggest a possible role of sNRP1 in modulating fetal growth and its potential as a biomarker for FGR. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Serum levels of soluble FMS-like tyrosine kinase 1 and endothelial glycocalyx components in early- and late-onset preeclampsia

INTRODUCTION

The most popular model of preeclampsia (PE) is a two-stage one in which the first stage involves a decreased perfusion of the placenta and the second stage is characterized by maternal endothelial injury and dysfunction. This model seems to be more appropriate for early-onset PE, than for the late-onset disease, as in the case of the latter the event of reduced placental perfusion seems is less obvious.The aim of the study was to assess the possible correlations between the serum levels of soluble FMS-like tyrosine kinase 1 (sFlt-1) and the components of endothelial glycocalyx (EG), namely syndecan -1 (SDC-1) and hyaluronan (HA), as the markers of endothelial damage, in patients with early- and late-onset PE.

MATERIALS AND METHODS

The study was conducted among 60 women in their late second and third trimester of the singleton pregnancy, including 20 patients with early-onset PE, 20 with late-onset PE, and 20 women with normal pregnancy, who served as the control group. All patients were hospitalized between 2015 and 2018 at the Division of Reproduction of Poznan University of Medical Sciences. The women in the control group were matched by gestational age with the patients in the study groups.

RESULTS

The median serum level of sFlt-1 was the highest in the patients with early-onset PE (3.53 (2.73-4.5) pg/ml) but it was not statistically different from the level in the patients with late-onset PE (3.14 (2.2-3.4) pg/ml). The mean serum level of SDC-1 also did not differ significantly between the two groups of patients with PE (6.17 ± 2.2 ng/ml in early-onset PE; 6.42 ± 2.2 ng/ml in late-onset PE). Both values of SDC-1 were significantly lower than that in the healthy pregnant women (11 ± 2.62 ng/ml, p < .001). The median concentrations of HA did not differ between patients with early- (236.6 (101.1-351.9) ng/ml) and late-onset PE (234.7 (46.8-324.2) ng/ml). However, the levels in these study groups were significantly higher than in the control group (113.9 (30.9-379.8) ng/ml, p < .001). There was no significant correlation found between the serum concentrations of sFlt-1 and both HA and SDC-1; however, such trend was noticed between the serum concentrations of sFlt-1 and HA in patients with early-onset PE, but not in those with the late-onset disease.

CONCLUSIONS

Evaluation of serum concentrations of HA in patients with PE was found to be more useful in the assessment of endothelial injury, compared to the assessment of SDC-1.The degree of EG damage was comparable in patients with early- and late-onset PE. The pathomechanism of the damage seems to be more sFlt-1 dependent in patients withearly- onset PE than in the case of late-onset disease. The two-stage model of PE is more appropriate for early - onset PE, whereas the pathophysiology of the late-onset disease is rather more complex and heterogenous.

Association of Preeclampsia in Term Births With Neurodevelopmental Disorders in Offspring

IMPORTANCE

Preeclampsia during pregnancy has been linked to an increased risk of cerebral palsy in offspring. Less is known about the role of preeclampsia in other neurodevelopmental disorders.

OBJECTIVE

To determine the association between preeclampsia and a range of adverse neurodevelopmental outcomes in offspring after excluding preterm births.

DESIGN, SETTING, AND PARTICIPANTS

This prospective, population-based cohort study included singleton children born at term from January 1, 1991, through December 31, 2009, and followed up through December 31, 2014 (to 5 years of age), using Norway's Medical Birth Registry and linked to other demographic, social, and health information by Statistics Norway. Data were analyzed from May 30, 2018, to November 17, 2019.

EXPOSURES

Maternal preeclampsia.

MAIN OUTCOMES AND MEASURES

Associations between preeclampsia in term pregnancies and cerebral palsy, attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), epilepsy, intellectual disability, and vision or hearing loss using multivariable logistic regression.

RESULTS

The cohort consisted of 980 560 children born at term (48.8% female and 51.2% male; mean [SD] gestational age, 39.8 [1.4] weeks) with a mean (SD) follow-up of 14.0 (5.6) years. Among these children, 28 068 (2.9%) were exposed to preeclampsia. Exposed children were at increased risk of ADHD (adjusted odds ratio [OR], 1.18; 95% CI, 1.05-1.33), ASD (adjusted OR, 1.29; 95% CI, 1.08-1.54), epilepsy (adjusted OR, 1.50; 95% CI, 1.16-1.93), and intellectual disability (adjusted OR, 1.50; 95% CI, 1.13-1.97); there was also an apparent association between preeclampsia exposure and cerebral palsy (adjusted OR, 1.30; 95% CI, 0.94-1.80).

CONCLUSIONS AND RELEVANCE

Preeclampsia is a well-established threat to the mother. Other than the hazards associated with preterm delivery, the risks to offspring from preeclampsia are usually regarded as less important. This study's findings suggest that preeclampsia at term may have lasting effects on neurodevelopment of the child.

Use of Placental Growth Factor for Trisomy 21 Screening in Pregnancy: A Systematic Review

Background  Prenatal serum screening is an important modality to screen for aneuploidy in pregnancy. The addition of placental growth factor (PLGF) to screen for trisomy 21 remains controversial. Objective  To determine whether the addition of PLGF to combined serum aneuploidy screening improves detection rates (DRs) for trisomy 21. Study Design  We performed a systematic review of the literature until October 2019 to determine the benefits of adding PLGF to prenatal screening. We performed a goodness-of-fit test and retrieved the coefficient of determinations ( R ² ) as a function of false positive rates (FPRs), providing mean-weighted improvements in the DRs after accounting for PLGF levels. Results  We identified 51 studies, of which 8 met inclusion criteria (834 aneuploidy cases and 105,904 euploid controls). DRs were proportional to FPR across all studies, ranging from 59.0 to 95.3% without PLGF and 61.0 to 96.3% with PLGF (FPR 1-5%). Goodness-of-fit regression analysis revealed a logarithmic distribution of DRs as a function of the FPR, with R ²  = 0.109 (no PLGF) and R ²  = 0.06 (PLGF). Two-sample Kolmogorov-Smirnov's test reveals a p -value of 0.44. Overall, addition of PLGF improves DRs of 3.3% for 1% FPR, 1.7% for 3% FPR, and 1.4% for 5% FPR, respectively. Conclusion  Addition of PLGF to prenatal screening using serum analytes mildly improves trisomy 21 DRs as a function of FPRs.

A bibliometric analysis of Intrauterine Growth Restriction research

Intrauterine growth restriction (IUGR) is not a new subject in pregnancy. Nevertheless, this concept has newly begun to be integrated into pregnancy studies. We recognized articles that were published in English from 1977 to 2019 through electronic searches of the Web of Science™ database. The WoS database was searched for all published articles that compared preeclampsia from 1977 to January 2020. About 1469 documents in obstetrics and gynecology areas were analyzed in WoS database. VOSviewer software was employed to visualize the networks. The survey resulted in a 1469 published documents from 1977 to 2020. 'Gratacos' from Spain and 'Cetin' from Italy contributed the most publications. The greatest contribution came from the 'USA' (n = 498), 'Italy' (n = 155), and 'England' (n = 147). Furthermore, our results found that among these journals, the 'AJOG' (n = 318) and the 'Reproductive Sciences' (n = 209) published the largest number of papers. The top 100 most cited papers showed that 30% were reported in the 'AJOG'. About half the articles were published in the last decade and the most common studies were research paper (77%). The co-occurrence and co-citation analysis showed that the study formed four clusters. Finally, the strategic map was designed. We found that there existed an increasing trend in the large amount of publication on IUGR from 1977 to 2020. The number of studies in IUGR has substantially improved in the last decade. Authors from the 'USA' appeared the most proactive in addressing the IUGR area. By studying these articles, we propose important to support not only for grinding the IUGR challenges field but also for designing a new trend in this area.

Influence of Estrogens on Uterine Vascular Adaptation in Normal and Preeclamptic Pregnancies

During pregnancy, the maternal cardiovascular system undergoes significant changes, including increased heart rate, cardiac output, plasma volume, and uteroplacental blood flow (UPBF) that are required for a successful pregnancy outcome. The increased UPBF is secondary to profound circumferential growth that extends from the downstream small spiral arteries to the upstream conduit main uterine artery. Although some of the mechanisms underlying uterine vascular remodeling are, in part, known, the factors that drive the remodeling are less clear. That higher circulating levels of estrogens are positively correlated with gestational uterine vascular remodeling suggests their involvement in this process. Estrogens binding to the estrogen receptors expressed in cytotrophoblast cells and in the uterine artery wall stimulate an outward hypertrophic remodeling of uterine vasculature. In preeclampsia, generally lower concentrations of estrogens limit the proper uterine remodeling, thereby reducing UPBF increases and restricting the growth of the fetus. This review aims to report estrogenic regulation of the maternal uterine circulatory adaptation in physiological and pathological pregnancy that favors vasodilation, and to consider the underlying molecular mechanisms by which estrogens regulate uteroplacental hemodynamics.

Why Do Intrauterine Exposure to Air Pollution and Cigarette Smoke Increase the Risk of Asthma?

The prevalence of childhood asthma is increasing worldwide and increased in utero exposure to environmental toxicants may play a major role. As current asthma treatments are not curative, understanding the mechanisms underlying the etiology of asthma will allow better preventative strategies to be developed. This review focuses on the current understanding of how in utero exposure to environmental factors increases the risk of developing asthma in children. Epidemiological studies show that maternal smoking and particulate matter exposure during pregnancy are prominent risk factors for the development of childhood asthma. We discuss the changes in the developing fetus due to reduced oxygen and nutrient delivery affected by intrauterine environmental change. This leads to fetal underdevelopment and abnormal lung structure. Concurrently an altered immune response and aberrant epithelial and mesenchymal cellular function occur possibly due to epigenetic reprograming. The sequelae of these early life events are airway remodeling, airway hyperresponsiveness, and inflammation, the hallmark features of asthma. In summary, exposure to inhaled oxidants such as cigarette smoking or particulate matter increases the risk of childhood asthma and involves multiple mechanisms including impaired fetal lung development (structural changes), endocrine disorders, abnormal immune responses, and epigenetic modifications. These make it challenging to reduce the risk of asthma, but knowledge of the mechanisms can still help to develop personalized medicines.

Relationships of serum placental growth factor and soluble fms-like tyrosine kinase-1 with fetal and uterine artery Doppler indices in pre-eclampsia

OBJECTIVE

To compare serum placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) concentrations among women with pre-eclampsia and healthy control women and to evaluate the associations of serum PlGF and sFlt-1 with fetal and uterine artery Doppler indices in pre-eclampsia.

METHODS

A prospective cross-sectional study of 33 women with pre-eclampsia and 33 normotensive pregnant women attending a university hospital in China between January and November 2014. Serum PlGF and sFlt-1 were assayed by enzyme linked immunosorbent assays. Doppler indices of the uterine artery, umbilical artery, fetal middle cerebral artery, and ductus venosus were measured.

RESULTS

The pulsatility index of the uterine artery was negatively correlated with PlGF (r, -0.487; P=0.004) and positively correlated with sFlt-1 (r, 0.420; P=0.015). Gestational age at birth was positively correlated with PlGF (r, 0.601, P<0.001) and negatively correlated with sFlt-1 (r, -0.568; P=0.001). Birth weight was positively correlated with PlGF (r, 0.555; P=0.001) and negatively correlated with sFlt-1 (r, -0.552; P=0.001). Apgar score was negatively correlated with sFlt-1 (r, -0.427; P=0.017).

CONCLUSION

Lower PlGF and higher sFlt-1 levels in maternal serum were significantly associated with increased uterine arterial impedance in pre-eclampsia.

Correlation between uterine artery Doppler and the sFlt-1/PlGF ratio in different phenotypes of placental dysfunction

OBJECTIVE

To explore correlations between the sFlt-1/PlGF ratio and uterine arteries (UtA) Doppler indexes in placental dysfunction-related disorders (PDD).

METHODS

We prospectively included women with a singleton pregnancy with preeclampsia (PE) only (n = 22), preeclampsia with fetal growth restriction (FGR) (n = 32), FGR only (n = 12), or normal pregnancy (n = 29).

RESULTS

In PDDs, significantly positive correlations between the sFlt-1/PlGF ratio and the mean UtA pulsatility (mPI-UtA), as well as the resistance index (mRI-UtA) were found (p = 0.015, p = 0.019, respectively), but not in normal pregnancies. PDD with signs of impaired placentation, evidenced by the increased sFlt-1/PlGF ratio and mPI-UtA, was found in 50.0%, and, by the increased sFlt-1/PlGF ratio and mRI-UtA, in 65.2%. PDD without signs of impaired placentation, evidenced by the increased sFlt-1/PlGF ratio but normal mPI-UtA, was found in 24.2%, and, by the increased sFlt-1/PlGF ratio but normal mRI-UtA, in 7.6%. A substantial proportion of women with signs of impaired placentation were diagnosed with FGR with or without PE.

CONCLUSION

In PDD, the sFlt-1/PlGF ratio and UtA Doppler indexes increase proportionally. Correlations between the sFlt-1/PlGF ratio and UtA Doppler indexes might help to distinguish between PDDs with and without impaired placentation. However, further studies are needed to explore the correlations in different phenotypes of PDD.

Are the Cognitive Alterations Present in Children Born From Preeclamptic Pregnancies the Result of Impaired Angiogenesis? Focus on the Potential Role of the VEGF Family

Evidence from clinical studies has proposed that children born from preeclamptic women have a higher risk of suffering neurological, psychological, or behavioral alterations. However, to date, the mechanisms behind these outcomes are poorly understood. Here, we speculate that the neurodevelopmental alterations in the children of preeclamptic pregnancies result from impaired angiogenesis. The pro-angiogenic factors vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) are key regulators of both vascular and neurological development, and it has been widely demonstrated that umbilical blood of preeclamptic pregnancies contains high levels of soluble VEGF receptor type 1 (sFlt-1), a decoy receptor of VEGF. As a consequence, this anti-angiogenic state could lead to long-lasting neurological outcomes. In this non-systematic review, we propose that alterations in the circulating concentrations of VEGF, PlGF, and sFlt-1 in preeclamptic pregnancies will affect both fetal cerebrovascular function and neurodevelopment, which in turn may cause cognitive alterations in post-natal life.

Assessing the sensitivity of placental growth factor and soluble fms-like tyrosine kinase 1 at 36 weeks' gestation to predict small-for-gestational-age infants or late-onset preeclampsia: a prospective nested case-control study

Background

Fetal growth restriction is a disorder of placental dysfunction with three to four-fold increased risk of stillbirth. Fetal growth restriction has pathophysiological features in common with preeclampsia. We hypothesised that angiogenesis-related factors in maternal plasma, known to predict preeclampsia, may also detect fetal growth restriction at 36 weeks’ gestation. We therefore set out to determine the diagnostic performance of soluble fms-like tyrosine kinase 1 (sFlt-1), placental growth factor (PlGF), and the sFlt-1:PlGF ratio, measured at 36 weeks’ gestation, in identifying women who subsequently give birth to small-for-gestational-age (SGA; birthweight <10th centile) infants. We also aimed to validate the predictive performance of the analytes for late-onset preeclampsia in a large independent, prospective cohort.

Methods

A nested 1:2 case-control study was performed including 102 cases of SGA infants and a matched group of 207 controls; and 39 cases of preeclampsia. We determined the diagnostic performance of each angiogenesis-related factor, and of their ratio, to detect SGA infants or preeclampsia, for a predetermined 10% false positive rate.

Results

Median plasma levels of PlGF at 36 weeks’ gestation were significantly lower in women who subsequently had SGA newborns (178.5 pg/ml) compared to normal birthweight controls (326.7 pg/ml, p < 0.0001). sFlt-1 was also higher among SGA cases, but this was not significant after women with concurrent preeclampsia were excluded. The sensitivity of PlGF to predict SGA infants was 28.8% for a 10% false positive rate. The sFlt-1:PlGF ratio demonstrated better sensitivity for preeclampsia than either analyte alone, detecting 69.2% of cases for a 10% false positive rate.

Conclusions

Plasma PlGF at 36 weeks’ gestation is significantly lower in women who subsequently deliver a SGA infant. While the sensitivity and specificity of PlGF currently limit clinical translation, our findings support a blood-based biomarker approach to detect late-onset fetal growth restriction. Thirty-six week sFlt-1:PlGF ratio predicts 69.2% of preeclampsia cases, and could be a useful screening test to triage antenatal surveillance.

Electronic supplementary material

The online version of this article (10.1186/s12884-018-1992-x) contains supplementary material, which is available to authorized users.

Adverse pregnancy outcomes and imbalance in angiogenic growth mediators and oxidative stress biomarkers is associated with advanced maternal age births: A prospective cohort study in Ghana

Background

Advanced maternal age (AMA) has been associated with negative pregnancy outcomes. Oxidative stress (OS) and defective placental dysfunction are contributing factors. This study determined the association between AMA and adverse pregnancy outcomes, OS biomarkers and angiogenic growth mediators (AGMs) in normal pregnancies.

Methods

This prospective cohort study conducted at the Obstetrics and Gynaecology (O&G) Department of the Komfo Anokye Teaching Hospital (KATH) finally included 175 normal pregnant women comprising, 58 AMA (35–45 years), 55 (30–34 years) and 62 optimal childbearing age (20–29 years). Venous blood samples were collected at 28–32 weeks for soluble fms-like tyrosine kinase-1 (sFlt-1), placental growth factor (PIGF), 8-epiprostaglandinF2-α (8-epi-PGF2α) and total antioxidant capacity (TAC) assays.

Results

Pregnancies of AMA had a significantly higher levels of sFlt-1, 8-epi-PGF2α and 8-epi-PGF2α: PIGF ratio but a reduced level of PIGF, TAC and PIGF: sFlt-1 ratio compared to 20–29 years (p<0.0001). A significant negative correlation between AMA and PIGF (r = -0.294; p = 0.038); TAC (r = -0.215; p = 0.001) and PIGF: sFlt-1 ratio (r = -0.457; p<0.0001) and a positive correlation with sFlt-1 (r = 0.269; p = 0.017), 8-epiPGF2α (r = 0.277; p = 0.029) and 8-epi-PGF2: PIGF ratio (r = 0.461; p<0.0001) levels were observed. The adjusted odds ratio (aOR), and 95% confidence interval, and p value for the significant independent adverse outcomes associated with AMA were emergency caesarean section [21.7 (5.9–121.3), p<00001], elective caesarean section [2.7(0.9–5.8), p = 0.0105], stillbirth [12.6(1.4–82.1), p<0.0001], post-partum haemorrhage [4.3(1.1–18.5), p = 0.0094], preterm delivery [8.2(3.5–28.4), p<0.0001], low birth weight babies [9.7(2.8–29.3), p<0.0001], birth asphyxia [3.8(1.6–12.7), p = 0.0054], Apgar score ≤ 7 after 5 min for babies [10.1(4.7–23.2), p<0.0001], placental abruption [3.5(1.3–8.4), p = 0.0117] and intrauterine growth restriction (IUGR) [4.6(2.3–12.9), p = 0.0001].

Conclusion

AMA pregnancies correlate with adverse pregnancy outcomes and imbalance in OS biomarkers and AGMs. It is incumbent on health care givers to provide effective antenatal care among AMA mothers as early identification of these imbalance and treatment can prevent adverse pregnancy outcomes.

The profiles of soluble adhesion molecules in the "great obstetrical syndromes". J Matern Fetal Neonatal Med 2018;32:2113-2136. [PMID: 29320948 DOI: 10.1080/14767058.2018.1427058]

OBJECTIVE

The objective of this study was to determine the profiles of maternal plasma soluble adhesion molecules in patients with preeclampsia, small-for-gestational-age (SGA) fetuses, acute pyelonephritis, preterm labor with intact membranes (PTL), preterm prelabor rupture of the membranes (preterm PROM), and fetal death.

MATERIALS AND METHODS

A cross-sectional study was conducted to determine maternal plasma concentrations of sE-selectin, sL-selectin, and sP-selectin as well as sICAM-1, sVCAM-1, and sPECAM-1 in patients with (1) an uncomplicated pregnancy (control, n = 100); (2) preeclampsia (n = 94); (3) SGA fetuses (in women without preeclampsia/hypertension, n = 45); (4) acute pyelonephritis (n = 25); (5) PTL (n = 53); (6) preterm PROM (n = 24); and (7) fetal death (n = 34). Concentrations of soluble adhesion molecules and inflammatory cytokines (tumor necrosis factor (TNF)-α and interleukin (IL)-8) were determined with sensitive and specific enzyme-linked immunoassays.

RESULTS

In comparison to women with a normal pregnancy, (1) women with preeclampsia had higher median concentrations of sE-selectin, sP-selectin, and sVCAM-1, and a lower concentration of sL-selectin (all p values < .001); (2) patients with SGA fetuses had higher median concentrations of sE-selectin, sP-selectin, and sVCAM-1 (all p values < .05); (3) patients with a fetal death had higher median concentrations of sE-selectin and sP-selectin (all p values < .05); (4) patients with acute pyelonephritis had higher median plasma concentrations of sE-selectin, sICAM-1, and sVCAM-1 (all p values < .001); (5) patients with preeclampsia and acute pyelonephritis, plasma concentrations of sVCAM-1, sE-selectin, and sP-selectin correlated with those of the proinflammatory cytokines TNF-α and interleukin (IL)-8 (all p values < .05); (6) patients with PTL had a higher median concentration of sP-selectin and a lower median concentration of VCAM-1 (all p values < .05); and (7) women with preterm PROM had lower median concentrations of sL-selectin and sVCAM-1 (all p values < .05).

CONCLUSIONS

The results of this study show that endothelial cell activation/dysfunction reflected by the plasma concentration of sE-selectin is not specific to preeclampsia but is present in pregnancies complicated by SGA fetuses, acute pyelonephritis, and fetal death. Collectively, we report that each obstetrical syndrome appears to have a stereotypical profile of soluble adhesion molecules in the peripheral circulation.

Adaptation of the Cutaneous Microcirculation in Preterm Neonates

OBJECTIVE

Transition from fetal to neonatal circulation is characterized by multiple hemodynamic changes. The role of the microcirculation in this process is underexposed. Visualizing the cutaneous microcirculation can help us understand peripheral perfusion in a noninvasive manner.

METHODS

Cutaneous microcirculation of term and preterm infants born below 32 weeks of GA was measured in the first month of life using IDF imaging. Linear mixed modeling was used to identify clinical variables which influence the cutaneous microcirculation.

RESULTS

Sixty preterm and 33 term infants were included. TVD of preterm infants significantly decreased in the first month of life (31.7 mm/mm(2)  day 1 vs 27.9 mm/mm(2)  day 28), but remained significantly higher compared to TVD of term infants on day 1 (25.8 mm/mm(2) ). Besides postnatal age, no clinical variables were associated with TVD. Infants born SGA had significantly higher TVD values directly after birth than those born appropriate for GA (35.4 mm/mm(2) vs 31.6 mm/mm(2) ; p = 0.015).

CONCLUSIONS

TVD decreases in the first month after birth and is higher in preterm infants compared to those born term. Differences in antenatal oxygen exposure might explain the adaptation of the microcirculation.

Maternal Circulating Placental Growth Factor and Neonatal Metabolic Health Biomarkers in Small for Gestational Age Infants

Small for gestational age (SGA) infants are at increased risk of type 2 diabetes in adulthood. It is unknown whether any prenatal biomarkers are helpful for identifying SGA infants with altered metabolic health profile at birth or later life. In a nested study of 162 SGA (birth weight < 10th percentile) and 161 optimal birth weight (25th-75th percentiles) control infants in the 3D (design, develop and discover) birth cohort in Canada, we assessed whether maternal circulating placental growth factor (PlGF), a biomarker of placental function, is associated with metabolic health biomarkers in SGA infants. Main outcomes were cord plasma insulin, proinsulin, insulin-like growth factor-I (IGF-I), leptin, and high-molecular weight (HMW) adiponectin concentrations. Maternal PlGF concentrations at 32-35 weeks of gestation were substantially lower in SGA versus control infants (P < 0.001), so as were cord plasma proinsulin (P = 0.005), IGF-I (P < 0.001), leptin (P < 0.001), and HMW adiponectin (P = 0.002) concentrations. In SGA infants with both low (<25th percentile) and normal maternal PlGF concentrations, cord plasma IGF-I and leptin concentrations were lower than control infants, but the decreases were to a greater extent in SGA infants with low maternal PlGF. Cord blood leptin levels were lower comparing SGA infants with low vs. normal maternal PlGF levels (P = 0.01). SGA infants with low maternal circulating PlGF levels at late gestation were characterized by greater decreases in cord blood IGF-I and leptin concentrations. Maternal circulating PlGF appears to be associated with neonatal metabolic health profile in SGA infants.

Omega-3 Long-Chain Polyunsaturated Fatty Acids and Preeclampsia: Trials Say "No," but Is It the Final Word?

Preeclampsia is a dangerous disorder of pregnancy, defined as hypertension with proteinuria. Its nature remains elusive, and measures of prevention and treatment are limited. Observational studies have suggested that preeclampsia is associated with low intake of omega-3 long-chain polyunsaturated fatty acids (LCPUFA). In recent decades, researchers studied LCPUFA supplementation as a measure to prevent preeclampsia. Most of these trials and later systematic reviews yielded negative results. However, these trials had several important limitations associated with heterogeneity and other issues. Recent research suggests that preeclampsia trials should take into consideration the gender of the fetus (and thus sexual dimorphism of placenta), the positive effect of smoking on preeclampsia prevalence, and the possibility that high doses of LCPUFA mid-term or later may promote the disorder instead of keeping it at bay. In this review, we discuss these issues and future prospects for LCPUFA in preeclampsia research.

Angiogenic factors for prediction of preeclampsia and intrauterine growth restriction onset in high-risk women: AngioPred study

OBJECTIVE

The study aimed to compare the level of two angiogenic factors, soluble fms-like tyrosine kinase-1 (sFlt1) and soluble endoglin (sEng), for the prediction of preeclampsia and intrauterine growth restriction in high-risk pregnant women.

METHODS

A prospective multicenter cohort study of 200 pregnant patients was conducted between June 2008 and October 2010. sFlt1 and sEng were measured by enzyme-linked immunosorbent assay.

RESULTS

Forty-five patients developed a placenta-mediated adverse pregnancy outcome. Plasma levels of sFlt1 and sEng were higher in patients who will experience a preeclampsia at 28, 32, and 36 weeks compared with patients with no complication. The same results were observed for intrauterine growth restriction. Plasma levels of sFlt1 and sEng were not significantly different for patients with preeclampsia compare to patients with intrauterine growth restriction. Patients with early pre-eclampsia (PE) had very high rates of angiogenic factors at 20, 24, and 28 weeks. Patients with late PE and early and late intrauterine growth retardation (IUGR) had high rates at 32 and 36 weeks.

CONCLUSION

In high-risk women, angiogenic factors are disturbed before the onset of preeclampsia and this is true for intrauterine growth restriction.

The prediction of late-onset preeclampsia: Results from a longitudinal proteomics study

BACKGROUND

Late-onset preeclampsia is the most prevalent phenotype of this syndrome; nevertheless, only a few biomarkers for its early diagnosis have been reported. We sought to correct this deficiency using a high through-put proteomic platform.

METHODS

A case-control longitudinal study was conducted, including 90 patients with normal pregnancies and 76 patients with late-onset preeclampsia (diagnosed at ≥34 weeks of gestation). Maternal plasma samples were collected throughout gestation (normal pregnancy: 2-6 samples per patient, median of 2; late-onset preeclampsia: 2-6, median of 5). The abundance of 1,125 proteins was measured using an aptamers-based proteomics technique. Protein abundance in normal pregnancies was modeled using linear mixed-effects models to estimate mean abundance as a function of gestational age. Data was then expressed as multiples of-the-mean (MoM) values in normal pregnancies. Multi-marker prediction models were built using data from one of five gestational age intervals (8-16, 16.1-22, 22.1-28, 28.1-32, 32.1-36 weeks of gestation). The predictive performance of the best combination of proteins was compared to placental growth factor (PIGF) using bootstrap.

RESULTS

1) At 8-16 weeks of gestation, the best prediction model included only one protein, matrix metalloproteinase 7 (MMP-7), that had a sensitivity of 69% at a false positive rate (FPR) of 20% (AUC = 0.76); 2) at 16.1-22 weeks of gestation, MMP-7 was the single best predictor of late-onset preeclampsia with a sensitivity of 70% at a FPR of 20% (AUC = 0.82); 3) after 22 weeks of gestation, PlGF was the best predictor of late-onset preeclampsia, identifying 1/3 to 1/2 of the patients destined to develop this syndrome (FPR = 20%); 4) 36 proteins were associated with late-onset preeclampsia in at least one interval of gestation (after adjustment for covariates); 5) several biological processes, such as positive regulation of vascular endothelial growth factor receptor signaling pathway, were perturbed; and 6) from 22.1 weeks of gestation onward, the set of proteins most predictive of severe preeclampsia was different from the set most predictive of the mild form of this syndrome.

CONCLUSIONS

Elevated MMP-7 early in gestation (8-22 weeks) and low PlGF later in gestation (after 22 weeks) are the strongest predictors for the subsequent development of late-onset preeclampsia, suggesting that the optimal identification of patients at risk may involve a two-step diagnostic process.

Short-Term Exposure to Urban Air Pollution and Influences on Placental Vascularization Indexes

BACKGROUND

It has been widely demonstrated that air pollution can affect human health and that certain pollutant gases lead to adverse obstetric outcomes, such as preeclampsia and fetal growth restriction.

OBJECTIVES

We evaluated the influence of individual maternal exposure to air pollution on placental volume and vascularization evaluated in the first trimester of pregnancy.

METHODS

This was a cross-sectional study on low-risk pregnant women living in São Paulo, Brazil. The women carried passive personal NO₂ and O₃ monitors in the week preceding evaluation. We employed the virtual organ computer-aided analysis (VOCAL) technique using three-dimensional power Doppler ultrasound to evaluate placental volume and placental vascular indexes [vascularization index (VI), flow index (FI), and vascularization flow index (VFI)]. We analyzed the influence of pollutant levels on log-transformed placental vascularization and volume using multiple regression models.

RESULTS

We evaluated 229 patients. Increased NO₂ levels had a significant negative association with log of VI (p = 0.020 and beta = -0.153) and VFI (p = 0.024 and beta = -0.151). NO₂ and O₃ had no influence on the log of placental volume or FI.

CONCLUSIONS

NO₂, an estimator of primary air pollutants, was significantly associated with diminished VI and VFI in the first trimester of pregnancy.

Placental expression of sFlt-1 and PlGF in early preeclampsia vs. early IUGR vs. age-matched healthy pregnancies

OBJECTIVE

To investigate whether differences between early preeclampsia and early fetal growth restriction can be explained by differential placental expression patterns of sFlt-1, Flt-1, and PlGF.

METHODS

Placental tissues and maternal blood samples from six cases of preeclampsia, seven IUGR, and six age-matched controls were studied for mRNA and protein levels as well as protein localization and expression intensity.

RESULTS

Neither placental PlGF mRNA and protein expression nor placental villous trophoblast expression intensity of PlGF was altered by placental dysfunction.

CONCLUSION

High sFlt-1 concentrations may account for diminished maternal serum PlGF levels.

Relationship between hypoxia and downstream pathogenic pathways in preeclampsia

Defects in angiogenesis and mitochondrial function in the placenta contribute to the pathogenesis of preeclampsia; however upstream regulators of these pathways are not known. It has been argued that placental hypoxia secondary to abnormal spiral artery remodeling may play a causal role in the angiogenic and mitochondrial abnormalities noted in preeclampsia. The aim of this study was to evaluate the relationship between hypoxia-inducible factor-1α (HIF-1α) ¸ a surrogate of hypoxia, and soluble fms-tyrosine kinase 1 (sFlt1), a circulating anti-angiogenic factor, and microRNA 210 (miR-210), a microRNA that regulates mitochondrial function, in human placentas from preeclamptic and non-hypertensive pregnancies. We first confirmed a 2.5-fold upregulation of HIF-1α protein in placentas from preeclampsia when compared to non-hypertensive controls. Consistent with prior studies, we also observed a 10-fold upregulated sFlt1 mRNA and 2-fold upregulated miR-210 in preeclamptic tissue. Interestingly, while sFlt1 mRNA correlated with miR-210 in preeclampsia (R² = 0.77, p = 0.0004), there were no significant correlations between these molecules and HIF1α expression. We conclude that non-hypoxia pathways may be involved in the abnormal angiogenic and metabolic alterations noted in preeclampsia.

The use of angiogenic biomarkers in maternal blood to identify which SGA fetuses will require a preterm delivery and mothers who will develop pre-eclampsia

OBJECTIVE

To determine (1) whether maternal plasma concentrations of angiogenic and anti-angiogenic factors can predict which mothers diagnosed with "suspected small for gestational age fetuses (sSGA)" will develop pre-eclampsia (PE) or require an indicated early preterm delivery (≤ 34 weeks of gestation); and (2) whether risk assessment performance is improved using these proteins in addition to clinical factors and Doppler parameters.

METHODS

This prospective cohort study included women with singleton pregnancies diagnosed with sSGA (estimated fetal weight <10th percentile) between 24 and 34 weeks of gestation (n = 314). Plasma concentrations of soluble vascular endothelial growth factor receptor-1 (sVEGFR-1), soluble endoglin (sEng) and placental growth factor (PlGF) were determined in maternal blood obtained at the time of diagnosis. Doppler velocimetry of the umbilical (Umb) and uterine (UT) arteries was performed. The outcomes were (1) subsequent development of PE; and (2) indicated preterm delivery at ≤ 34 weeks of gestation (excluding deliveries as a result of spontaneous preterm labor, preterm pre-labor rupture of membranes or chorioamnionitis).

RESULTS

(1) The prevalence of PE and indicated preterm delivery was 9.2% (n = 29/314) and 7.3% (n = 23/314), respectively; (2) the area under the receiver operating characteristic curve (AUC) for the identification of patients who developed PE and/or required indicated preterm delivery was greater than 80% for the UT artery pulsatility index (PI) z-score and each biochemical marker (including their ratios) except sVEGFR-1 MoM; (3) using cutoffs at a false positive rate of 15%, women with abnormal plasma concentrations of angiogenic/anti-angiogenic factors were 7-13 times more likely to develop PE, and 12-22 times more likely to require preterm delivery than those with normal plasma MoM concentrations of these factors; (4) sEng, PlGF, PIGF/sEng and PIGF/sVEGFR-1 ratios MoM, each contributed significant information about the risk of PE beyond that provided by clinical factors and/or Doppler parameters: women who had low MoM values for these biomarkers were at 5-9 times greater risk of developing PE than women who had normal values, adjusting for clinical factors and Doppler parameters (adjusted odds ratio for PlGF: 9.1, PlGF/sEng: 5.6); (5) the concentrations of sVEGFR-1 and PlGF/sVEGFR-1 ratio MoM, each contributed significant information about the risk of indicated preterm delivery beyond that provided by clinical factors and/or Doppler parameters: women who had abnormal values were at 8-9 times greater risk for indicated preterm delivery, adjusting for clinical factors and Doppler parameters; and (6) for a two-stage risk assessment (Umb artery Doppler followed by Ut artery Doppler plus biochemical markers), among women who had normal Umb artery Doppler velocimetry (n = 279), 21 (7.5%) developed PE and 11 (52%) of these women were identified by an abnormal UT artery Doppler mean PI z-score (>2SD): a combination of PlGF/sEng ratio MoM concentration and abnormal UT artery Doppler velocimetry increased the sensitivity of abnormal UT artery Doppler velocimetry to 76% (16/21) at a fixed false-positive rate of 10% (p = 0.06).

CONCLUSION

Angiogenic and anti-angiogenic factors measured in maternal blood between 24 and 34 weeks of gestation can identify the majority of mothers diagnosed with "suspected SGA" who subsequently developed PE or those who later required preterm delivery ≤ 34 weeks of gestation. Moreover, incorporation of these biochemical markers significantly improves risk assessment performance for these outcomes beyond that of clinical factors and uterine and umbilical artery Doppler velocimetry.

Fluid Shear Stress Promotes Placental Growth Factor Upregulation in Human Syncytiotrophoblast Through the cAMP-PKA Signaling Pathway

The effects of fluid shear stress (FSS) on the human syncytiotrophoblast and its biological functions have never been studied. During pregnancy, the syncytiotrophoblast is the main source of placental growth factor (PlGF), a proangiogenic factor involved in the placental angiogenesis and the vascular adaptation to pregnancy. The role of FSS in regulating PlGF expression in syncytiotrophoblasts is unknown. We investigated the impact of FSS on the production and secretion of the PlGF by the human syncytiotrophoblasts in primary cell culture. Laminar and continuous FSS (1 dyn cm^-2) was applied to human syncytiotrophoblasts cultured in a parallel-plate flow chambers. Secreted levels of PlGF, sFlt-1 (soluble fms-like tyrosin kinase-1), and prostaglandin E2 were tested by immunologic assay. PlGF levels of mRNA and intracellular protein were examined by RT-PCR and Western blot, respectively. Intracellular cAMP levels were examined by time-resolved fluorescence resonance energy transfer cAMP accumulation assay. Production of cAMP and PlGF secretion was significantly increased in FSS conditions compared with static conditions. Western blot analysis of cell extracts exposed to FSS showed an increased phosphorylation of protein kinase A substrates and cAMP response element-binding protein on serine 133. FSS-induced phosphorylation of cAMP response element-binding protein and upregulation of PlGF were prevented by inhibition of protein kinase A with H89 (3 μmol/L). FSS also triggers intracellular calcium flux, which increases the synthesis and release of prostaglandin E2. The enhanced intracellular cAMP in FSS conditions was blocked by COX1/COX2 (cyclooxygenase) inhibitors, suggesting that the increase in prostaglandin E2 production could activate the cAMP/protein kinase A pathway in an autocrine/paracrine fashion. FSS activates the cAMP/protein kinase A pathway leading to upregulation of PlGF in human syncytiotrophoblast.

Role of the fetoplacental endothelium in fetal growth restriction with abnormal umbilical artery Doppler velocimetry

Growth-restricted fetuses with absent or reversed end-diastolic velocities in the umbilical artery are at substantially increased risk for adverse perinatal and long-term outcome, even in comparison to growth-restricted fetuses with preserved end-diastolic velocities. Translational studies show that this Doppler velocimetry correlates with fetoplacental blood flow, with absent or reversed end-diastolic velocities signifying abnormally elevated resistance within the placental vasculature. The fetoplacental vasculature is unique in that it is not subject to autonomic regulation, unlike other vascular beds. Instead, humoral mediators, many of which are synthesized by local endothelial cells, regulate placental vascular resistance. Existing data demonstrate that in growth-restricted pregnancies complicated by absent or reversed umbilical artery end-diastolic velocities, an imbalance in production of these vasoactive substances occurs, favoring vasoconstriction. Morphologically, placentas from these pregnancies also demonstrate impaired angiogenesis, whereby vessels within the terminal villi are sparsely branched, abnormally thin, and elongated. This structural deviation from normal placental angiogenesis restricts blood flow and further contributes to elevated fetoplacental vascular resistance. Although considerable work has been done in the field of fetoplacental vascular development and function, much remains unknown about the mechanisms underlying impaired development and function of the human fetoplacental vasculature, especially in the context of severe fetal growth restriction with absent or reversed umbilical artery end-diastolic velocities. Fetoplacental endothelial cells are key regulators of angiogenesis and vasomotor tone. A thorough understanding of their role in placental vascular biology carries the significant potential of discovering clinically relevant and innovative approaches to prevention and treatment of fetal growth restriction with compromised umbilical artery end-diastolic velocities.

Association between adverse pregnancy outcome and imbalance in angiogenic regulators and oxidative stress biomarkers in gestational hypertension and preeclampsia

Background

Gestational hypertension (GH) and Preeclampsia, (PE) are the most complicated amongst hypertensive disorders of pregnancy. The mechanism that links hypertension in pregnancy to adverse maternal outcomes is not fully understood though some relate this to endothelial dysfunction originating from an imbalanced angiogenic regulators and oxidative stress biomarkers. This study assessed the correlation between angiogenic regulators and oxidative stress biomarker levels with adverse pregnancy outcomes among GH and PE participants.

Methods

A cohort of pregnant women who received antenatal care at the Obstetrics and Gynaecology department of the Komfo Anokye Teaching Hospital (KATH) were followed. During their antenatal visits, 100 developed PE and 70 developed GE, of these, 50 PE and 50 GH gave informed consent. Their blood samples were taken at time of diagnosis and 48 h post-partum. 50 other aged-matched women who did not develop neither GH nor PE were selected as controls. Placental growth factor (PLGF), soluble fms-like tyrosine kinase 1 (sFlt-1) and 8-epi-prostaglandin F2alpha (8-epi-PGF2α) levels were estimated by ELISA and total antioxidant capacity (T-AOC) was measured spectrophotometrically. Graphpad Prism was used for data analysis.

Results

Median levels of sFlt-1, 8-epi-PGF2α and sFlt-1/PLGF were elevated among participants with PE co-existing with intrauterine fetal death (IUFD), placental abruptio, placental previa, HELLP syndrome and intrauterine growth restriction (IUGR) compared to PE without adverse outcomes (p = 0.041, p = 0.005, p = 0.0002). Levels of PLGF, T-AOC and PLGF/sFlt-1 were significantly reduced among participants with PE co-existing with IUFD, placental abruptio, placental previa, HELLP syndrome and IUGR compared to PE without adverse outcomes (p = 0.0013, p = 0.006, p < 0.0001). A significant negative correlation of IUGR (p = 0.0030; p < 0.0001), placental abruptio (p < 0.0001; p < 0.0001), IUFD (p < 0.0001; p < 0.0001), stillbirth (p = 0.0183 and p < 0.000), and postpartum haemorrhage (PPH) (p = 0.0420; p = 0.0044) were associated with both PLGF and T-AOC whilst a significant positive correlation of IUGR, placental abruptio (p < 0.0001; p < 0.0001), IUFD (p < 0.0001; p < 0.0001), stillbirth (p < 0.0001; p < 0.0001), and PPH (p = 0.0043; p = 0.0039) were observed with both sFlt-1 and 8-epi-PGF2α in PE.

Conclusions

Imbalance in the levels of angiogenic regulators and oxidative stress biomarkers correlates with adverse pregnancy outcomes among PE participants. Early identification of these imbalance would alert health care givers in anticipation of adverse pregnancy outcome and thus increased surveillance during pregnancy and parturition and measures to ameliorate the adverse outcome.

Update on the pathophysiological implications and clinical role of angiogenic factors in pregnancy

Angiogenic markers are now being incorporated into clinical practice for the screening, diagnosing, and monitoring of preeclampsia. Pregnancy requires both vasculogenesis and angiogenesis in the fetal compartment and angiogenesis in the maternal compartment. Abnormal angiogenesis in the placenta determines impaired remodeling of the maternal spiral arteries and placental underperfusion that may ultimately lead to fetal growth restriction and maternal preeclampsia. The dysregulation of angiogenesis in the placenta and maternal-fetal circulation has emerged as one of the main pathophysiological features in the development of placental insufficiency and its clinical consequences. Abnormal angiogenesis has also been related to other obstetric and fetal conditions such as peripartum cardiomyopathy and fetal cardiac defects. This opens up new challenges for our understanding of angiogenic involvement in maternal cardiovascular function and fetal cardiac development, and it offers new clinical opportunities. This review summarizes the current knowledge of the pathophysiological implications and the clinical role of angiogenic factors in pregnancy.

Characterization of the soluble fms-like tyrosine kinase-1 to placental growth factor ratio in pregnancies complicated by fetal growth restriction

OBJECTIVE

To characterize the values of the soluble fms-like tyrosine kinase-1 (sFlt-1) to placental growth factor (PlGF) ratio in pregnancies with fetal growth restriction with or without concurrent preeclampsia or hemolysis, elevated liver enzymes and low platelets syndrome (HELLP) and in pregnancies with normally grown fetuses with or without concurrent preeclampsia or HELLP.

METHODS

This is a case-control study performed in two centers (Berlin and Madrid) consisting of 171 singleton pregnancies complicated by fetal growth restriction (n=27), preeclampsia or HELLP (n=105) or preeclampsia or HELLP and fetal growth restriction (n=39) pairwise matched by gestational age with 171 healthy control pregnancies. Automated measurement of sFlt-1 and PlGF in maternal serum samples was performed after diagnosis (cases) and in gestational-age matched healthy control samples. Samples were analyzed for two timeframes: before and at or after 34 weeks of gestation.

RESULTS

Pregnancies with fetal growth restriction, preeclampsia or HELLP, and preeclampsia or HELLP and fetal growth restriction showed higher median values of sFlt-1/PlGF ratio than control pregnancies both before 34 weeks of gestation (90, 231, 514, and 3, respectively, P<.001) and at or after 34 weeks of gestation (117, 66, 165, and 11, respectively, P<.001). The differences among the case subgroups were not statistically different.

CONCLUSION

Fetal growth restriction is characterized by elevated maternal sFlt-1/PlGF ratio, reaching values as high as those observed in preeclampsia or HELLP.

LEVEL OF EVIDENCE

II.

Maternal/newborn VEGF-C936T interaction and its influence on the risk, severity and prognosis of preeclampsia, as well as on the maternal angiogenic profile

OBJECTIVE

To analyze the influence of maternal/newborn vascular endothelial growth factor (VEGF)-CT936 interaction as a modulating factor in preeclampsia as well as its influence on the maternal angiogenic balance.

METHODS

Seventy pairs of preeclamptic women/newborns and 94 pairs of normal pregnant mothers/newborns were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Serum VEGF and soluble VEGF receptor-1 (sVEGFR-1) levels were measured using ELISA.

RESULTS

The risk to develop mild (odds ratio; OR: 3.79, p = 0.008) and severe (OR: 2.94, p = 0.037) preeclampsia being increased in association with the CT936-VEGF genotype and increased in severe preeclampsia to 6.07 (p = 0.03) if the women were carriers of the homozygous TT936-VEGF genotype. The presence of the VEGF-T936 allele in both the mother and the newborn significantly increases the risk of pregnancy-induced hypertension (PIH), mild and severe preeclampsia. If both the mothers and newborns were carriers of the VEGF-T936 allele, significantly lower VEGF and higher sVEGFR-1 levels were observed for all types of preeclampsia. Pregnant women with PIH and severe preeclampsia delivered at a significantly earlier gestational age neonates with a significantly lower birth weight if both the preeclamptic mothers and their newborns were carriers of the VEGF-T936 allele.

CONCLUSIONS

Our study suggests the role of maternal/fetal VEGF-CT936 polymorphism as a modulating factor in preeclampsia, which affects the angiogenic balance in preeclamptic mothers, as well as their pregnancy outcome.

Comparison of placental growth factor and fetal flow Doppler ultrasonography to identify fetal adverse outcomes in women with hypertensive disorders of pregnancy: an observational study

BACKGROUND

Hypertensive disorders of pregnancy and intrauterine growth restriction (IUGR) are leading causes of maternal and perinatal morbidity and mortality. Failure to detect intrauterine growth restriction in women at high risk has been highlighted as a significant avoidable cause of serious fetal outcome. In this observational study we compare fetal flow using Doppler ultrasonography with a new test for placental growth factor (PlGF) to predict fetal adverse events.

METHODS

Eighty-nine women with hypertensive disorders of pregnancy (24 with chronic hypertension, 17 with gestational hypertension, 12 with HELLP syndrome, 19 with preeclampsia and 17 with superimposed preeclampsia) were enrolled. A single maternal blood sample to measure free PlGF (Alere Triage) taken before 35 weeks of pregnancy was compared to the last Doppler ultrasound measurement of fetal flow before delivery. PlGF was classified as normal (PlGF≥100 pg/ml), low (12<PlGF<100) or very low (PlGF≤12 pg/ml). A positive test for abnormal fetal flow was defined as either signs of centralisation of the fetal circulation or diastolic block or reverse flow in the umbilical artery or descending aorta; this was a criterion for delivery. Fetal outcomes were intrauterine growth restriction and birth before 37 weeks of pregnancy.

RESULTS

In total 61/89 women had a preterm birth and 22 infants had IUGR. Of those who delivered preterm, 20/20 women with abnormal fetal flow and 36/41 (87.8%) women with normal fetal flow had low or very low PlGF. Of those infants with IUGR, 22/22 had low or very low maternal PlGF and 10/22 had abnormal fetal flow.

CONCLUSIONS

PlGF may provide useful information before 35th gestational week to identify fetuses requiring urgent delivery, and those at risk of later adverse outcomes not identified by fetal flow Doppler ultrasonography.

Uterine artery Doppler and sFlt-1/PlGF ratio: usefulness in diagnosis of pre-eclampsia

OBJECTIVE

To evaluate the usefulness of the mean pulsatility index of the uterine arteries (mPI-UtA) and automated measurement of the soluble fms-like tyrosine kinase 1 (sFlt-1)/placental growth factor (PlGF) ratio on suspicion or at diagnosis of pre-eclampsia (PE).

METHODS

Patients with singleton pregnancies with PE (n = 60) diagnosed according to current recommendations, or with suspected PE (n = 32) defined by (1) blood pressure (BP) ≥ 160/100 mmHg, (2) BP ≥ 140/90 mmHg or proteinuria, together with suggestive clinical symptoms or (3) intrauterine growth restriction (IUGR) at < 34 + 0 weeks, were enrolled and mPI-UtA and the sFlt-1/PlGF ratio were measured. Values > 95(th) centile were considered abnormal. All cases were classified according to occurrence of PE and/or IUGR and subclassified, depending on gestational age at delivery, as early (< 34 + 0 weeks) or late (≥ 34 + 0 weeks).

RESULTS

PE was confirmed in 72 cases, in which 32 early deliveries occurred. Isolated IUGR was diagnosed in nine early cases and one late case, while the remaining 10 cases were late deliveries without PE or IUGR. In pregnancies in which PE and IUGR were excluded, mPI-UtA was abnormal in 40% but the sFlt-1/PlGF ratio was normal in 100%. In early PE, mPI-UtA at diagnosis was abnormal in 100% of cases with IUGR and in 91% without IUGR, while sFlt-1/PlGF was abnormal in 100% and 96%, respectively. In late PE, mPI-UtA was abnormal in 50% and 37% of cases with and without IUGR while the sFlt-1/PlGF ratio was abnormal in 50% and 26%, respectively.

CONCLUSION

Abnormal mPI-UtA and sFlt-1/PlGF ratio are common in early PE. In late PE, mPI-UtA is normal in most cases and thus not diagnostically useful. The sFlt-1/PlGF ratio shows high specificity but low sensitivity to confirm PE when suspected.

Evidence of an imbalance of angiogenic/antiangiogenic factors in massive perivillous fibrin deposition (maternal floor infarction): a placental lesion associated with recurrent miscarriage and fetal death

OBJECTIVE

Massive perivillous fibrin deposition (MPFD) is associated with serious complications of pregnancy including recurrent spontaneous abortion, fetal growth restriction, and fetal demise. The aim of this study was to determine whether maternal plasma concentrations of angiogenic/antiangiogenic factors in MPFD differ from those of uncomplicated pregnancies.

STUDY DESIGN

This retrospective longitudinal case-control study included MPFD cases (n = 10) and control patients (n = 175) with uncomplicated pregnancies who were enrolled in a longitudinal study and delivered at term. Serial plasma concentrations of placental growth factor (PlGF), soluble endoglin (sEng), and soluble vascular endothelial growth factor receptor (sVEGFR)-1 and -2 were determined by an enzyme-linked immunosorbent assay (cases, n = 28 samples; controls, n = 723 samples). Individual analyte concentrations were averaged across gestational age at specimen collection intervals. Linear mixed models were used to test for differences in log-transformed mean analyte concentrations both overall and as a function of time.

RESULTS

The following results were found: (1) patients with MPFD had a lower mean plasma PlGF concentration (P = .03) and higher mean plasma concentrations of sVEGFR-1 and sEng (both P < .01) than controls, adjusted for potential confounders; (2) the mean plasma concentration of PlGF differed further among cases and controls as a function of gestational age interval (P < .0001); however, mean sVEGFR-1 and sEng group differences as a function of gestational age interval approached but did not reach significance (P = .09 and P = .11, respectively); (3) patients with MPFD had lower mean plasma concentrations of PlGF/sVEGFR-1 (P < .0001) and PlGF/sEng (P < .001): both of these relationships differed further as a function of gestational age interval (both P < .0001); and (4) differences in mean sVEGFR-1, sEng, and the ratios of PlGF to sVEGFR-1 and PlGF to sEng were observed before 20 weeks of gestation.

CONCLUSION

An imbalance of angiogenic/antiangiogenic factors is present in patients with MPFD prior to the diagnosis. We propose that these changes participate in the mechanisms responsible for adverse pregnancy outcomes in patients with MPFD.

Can maternal serum placental growth factor estimation in early second trimester predict the occurrence of early onset preeclampsia and/or early onset intrauterine growth restriction? A prospective cohort study

AIM

To determine whether maternal serum placental growth factor (PlGF) estimation in early second trimester (20-22 weeks of gestation) can predict the occurrence of early onset preeclampsia and/or early onset intrauterine growth restriction (IUGR).

MATERIAL AND METHODS

A prospective cohort study was conducted on 722 women with singleton pregnancies, screened from the antenatal clinic, and serum PlGF levels were estimated at 20-22 weeks of gestation. A cut-off value of <155 pg/mL for serum PlGF was determined by receiver operating characteristic (ROC) curve analysis for identifying pregnant women at risk of developing early onset preeclampsia and/or early onset IUGR. Preeclampsia and IUGR were classified as early onset when diagnosed by 32 weeks of gestation. Univariate logistic regression analysis was used to analyze the association between serum PlGF level <155 pg/mL and the two outcome measures (i.e. early onset preeclampsia and early onset IUGR) and odds ratio (OR) was computed. P-value < 0.05 was considered statistically significant.

RESULTS

Maternal serum PlGF level <155 pg/mL at 20-22 weeks of gestation had a strong association with early onset preeclampsia (OR 8.35; 95% CI 1.79-18.94; P = 0.007) and with early onset IUGR (OR 10.73; 95% CI 4.08-20.23; P = 0.000). The sensitivity of serum PlGF < 155 pg/mL for predicting early onset preeclampsia and early onset IUGR were 82 and 84, respectively.

CONCLUSION

Maternal serum PlGF level estimation in early second trimester (20-22 weeks of gestation) may be useful in predicting the occurrence of early onset preeclampsia and/or early onset IUGR.

Air pollution exposure and markers of placental growth and function: the generation R study

BACKGROUND

Air pollution exposure during pregnancy might affect placental growth and function, perhaps leading to pregnancy complications.

OBJECTIVE

We prospectively evaluated the associations of maternal air pollution exposure with markers of placental growth and function among 7,801 pregnant women in the Netherlands.

METHODS

We estimated levels of particulate matter ≤ 10 µm in aerodynamic diameter (PM10) and nitrogen dioxide (NO2) at the home address for different periods during pregnancy using dispersion modeling techniques. Pro- and anti-angiogenic factors [placental growth factor (PlGF) and soluble fms-like tyrosine kinase 1 (sFlt-1), respectively] were measured in first- and second-trimester maternal blood and in fetal cord blood samples at delivery. Pulsatility index of the uterine and umbilical arteries was measured by Doppler ultrasound in second and third trimester, and notching was assessed in third trimester. Placenta weight and birth weight were obtained from medical records.

RESULTS

Higher PM10 and NO2 exposure levels were associated with lower second-trimester maternal sFlt-1 and PlGF levels. PM10 and NO2 exposures averaged over total pregnancy were associated with higher sFlt-1 and lower PlGF levels in fetal cord blood, consistent with an anti-angiogenic state. PM10 and NO2 exposures were not consistently associated with second- or third-trimester placental resistance indices. NO2 exposure was associated with third-trimester notching (odds ratio 1.33; 95% CI: 0.99, 1.78 per 10-µg/m3 increase in the prior 2 months). PM10 and NO2 exposures were associated with lower placenta weight (-11.8 g; 95% CI: -20.9, -2.7, and -10.7 g; 95% CI: -19.0, -2.4, respectively, per 10-µg/m3 increase in the prior 2 months), but not with placenta to birth weight ratio.

CONCLUSIONS

Our results suggest that maternal air pollution exposure may influence markers of placental growth and function. Future studies are needed to confirm these findings and explore the maternal and fetal consequences.