Vascular changes in fetal growth restriction: clinical relevance and future therapeutics

Expression and significance of CEMIP and CYP11B2 in serum in women with foetal growth restriction

BACKGROUND

Foetal growth restriction (FGR) occurs when a foetus fails to reach its growth potential. This observational study assessed the expression and significance of cell migration-including protein (CEMIP) and aldosterone synthase (CYP11B2) in the serum of pregnant women with FGR.

METHODS

40 singleton FGR-suffered pregnant women, as well as 40 normal singleton pregnant women, were enrolled. The expression of CEMIP and CYP11B2 in serum was detected in early pregnancy. The correlations between parameters were evaluated. The predictive variables for FGR were determined. The diagnostic value of CEMIP and CYP11B2 for FGR was analysed.

RESULTS

CEMIP and CYP11B2 mRNA expression in the serum of pregnant women with FGR decreased (both P < 0.001). CEMIP (95%CI: 0.802-0.921, P < 0.001) and CYP11B2 (95%CI: 0.795-0.907, P < 0.001) mRNA expression in serum and soluble fms like tyrosine kinase-1 (sFLT1)/placental growth factor (PlGF) ratio (95%CI: 0.866-0.974, P < 0.001) were independent predictors of FGR, and CEMIP (r = -0.578, P = 0.001) and CYP11B2 (r = -0.602, P < 0.001) mRNA expression in serum were negatively correlated with sFLT1/PlGF ratio. CEMIP (AUC = 0.741) and CYP11B2 (AUC = 0.764) mRNA expression in serum had good diagnostic value for FGR.

CONCLUSION

The expression of CEMIP and CYP11B2 is reduced in the serum of pregnant women with FGR and may become new diagnostic markers for FGR.

Impact of Ionizing Radiation Exposure on Placental Function and Implications for Fetal Programming

Accidental exposure to high-dose radiation while pregnant has shown significant negative effects on the developing fetus. One fetal organ which has been studied is the placenta. The placenta performs all essential functions for fetal development, including nutrition, respiration, waste excretion, endocrine communication, and immunological functions. Improper placental development can lead to complications during pregnancy, as well as the occurrence of intrauterine growth-restricted (IUGR) offspring. IUGR is one of the leading indicators of fetal programming, classified as an improper uterine environment leading to the predisposition of diseases within the offspring. With numerous studies examining fetal programming, there remains a significant gap in understanding the placenta's role in irradiation-induced fetal programming. This review aims to synthesize current knowledge on how irradiation affects placental function to guide future research directions. This review provides a comprehensive overview of placental biology, including its development, structure, and function, and summarizes the placenta's role in fetal programming, with a focus on the impact of radiation on placental biology. Taken together, this review demonstrates that fetal radiation exposure causes placental degradation and immune function dysregulation. Given the placenta's crucial role in fetal development, understanding its impact on irradiation-induced IUGR is essential.

The impact of maternal intrahepatic cholestasis during pregnancy on the growth trajectory of offspring: a population-based nested case‒control cohort study

BACKGROUND

Intrahepatic cholestasis of pregnancy (ICP) is associated with an increased risk of adverse fetal outcomes, yet its influence on offspring growth remains unclear. Our study dynamically tracks growth rates in children from ICP and healthy mothers and investigates the link between maternal liver function and developmental abnormalities in offspring.

METHOD

Our case‒control study involved 97 women with ICP and 152 with uncomplicated pregnancies nested in a cohort of their offspring, including 50 from the ICP group and 87 from the uncomplicated pregnancy group. We collected pediatric growth and development data, with a maximum follow-up duration of 36 months. Stratified analyses of children's height, weight, and head circumference were conducted, and Spearman's rank correlation was applied to examine the relationships between maternal serological markers and pediatric growth metrics.

RESULT

Maternal liver and renal functions, along with serum lipid profiles, significantly differed between the ICP and normal groups. In the ICP group, the offspring showed elevated alanine aminotransferase (ALT), direct bilirubin (DBIT), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and apolipoprotein B (APOB) levels. Notably, the length-for-age z score (LAZ), weight-for-age z score (WAZ), and head circumference-for-age z score (HCZ) were lower in ICP offspring compared with those from normal pregnancies within the 1- to 12-month age range (P < 0.05). However, no significant differences in LAZ, weight-for-length z score (WLZ), BMI-for-age z score (BAZ), or HCZ were observed between groups in the 13- to 36-month age range. Maternal maximum lactate dehydrogenase (LDH) and total bile acids (TBA) levels during pregnancy were inversely correlated with LAZ and WAZ in the first year. Furthermore, offspring of mothers with ICP exhibited a greater incidence of stunting (24% vs. 6.9%, P = 0.004) and abnormal HCZ (14% vs. 3.7%, P = 0.034).

CONCLUSIONS

Growth disparities in offspring of ICP-affected pregnancies were most significant within the 1- to 12-month age range. During this period, maximum maternal LDH and TBA levels were negatively correlated with LAZ and WAZ values of offspring. The observation of similar growth rates between ICP and control group offspring from 13 to 36 months suggested catch-up growth in the ICP group.

Cardiovascular decline in offspring during the perinatal period in an ovine model of fetal growth restriction

Fetal growth restriction (FGR) increases the risk cardiovascular disease (CVD) in adulthood. Placental insufficiency and subsequent chronic fetal hypoxemia are causal factors for FGR, leading to a redistribution of blood flow that prioritizes vital organs. Subclinical signs of cardiovascular dysfunction are evident in growth-restricted neonates; however, the mechanisms programming for CVD in adulthood remain unknown. This study aimed to determine the potential mechanisms underlying structural and functional changes within the heart and essential (carotid) and nonessential (femoral) vascular beds in growth-restricted lambs. Placental insufficiency was surgically induced in ewes at 89 days gestational age (dGA, term = 148dGA). Three age groups were investigated: fetal (126dGA), newborn (24 h after preterm birth), and 4-wk-old lambs. In vivo and histological assessments of cardiovascular indices were undertaken. Resistance femoral artery function was assessed via in vitro wire myography and blockade of key vasoactive pathways including nitric oxide, prostanoids, and endothelium-dependent hyperpolarization. All lambs were normotensive throughout the first 4 wk of life. Overall, the FGR cohort had more globular hearts compared with controls (P = 0.0374). A progressive decline in endothelium-dependent vasodilation was demonstrated in FGR lambs compared with controls. Further investigation revealed that impairment of the prostanoid pathway may drive this reduction in vasodilatory capacity. Clinical indicators of CVD were not observed in our FGR lambs. However, subclinical signs of cardiovascular dysfunction were present in our FGR offspring. This study provides insight into potential mechanisms, such as the prostanoid pathway, that may warrant therapeutic interventions to improve cardiovascular development in growth-restricted newborns.NEW & NOTEWORTHY Our findings provide novel insight into the potential mechanisms that program for cardiovascular dysfunction in growth-restricted neonates as our growth-restricted lambs exhibited a progressive decline in endothelium-dependent vasodilation in the femoral artery between birth and 4 wk of age. Subsequent analyses indicated that this reduction in vasodilatory capacity is likely to be mediated by the prostanoid pathway and prostanoids could be a potential target for therapeutic interventions for fetal growth restriction (FGR).

Cardiac morphology in neonates with fetal growth restriction

OBJECTIVE

Assess effects of fetal growth restriction (FGR) on cardiac modelling in premature and term neonates.

STUDY DESIGN

Prospective echocardiographic study of a cohort of FGR neonates (n = 21) and controls (n = 41) with normal prenatal growth and circulation.

RESULTS

Unadjusted for gestational age, birth weight, sex, and twin/singleton, Late-FGR neonates had smaller hearts than controls, with globular left ventricles and symmetrical right ventricles. Adjusted estimates showed smaller left ventricles and similarly sized right ventricles, with symmetrical left and right ventricles. Early-FGR (compared with Late-FGR) had smaller hearts and globular left ventricles in unadjusted estimates, but after adjustment, sizes and shapes were similar.

CONCLUSION

FGR had significant impact on cardiac modelling, seen in both statistical models unadjusted and adjusted for gestational age, birth weight, sex, and twin/singleton. The adjustments, however, refined the results and revealed more specific effects of FGR, thus underscoring the importance of statistical adjustments in such studies.

Role of prenatal fetal echocardiography in the assessment of intrauterine growth restriction

Background

Intrauterine growth restriction (IUGR) is a common diagnosis in obstetrics and carries an increased risk of perinatal mortality and morbidity. Identification of IUGR is crucial because proper evaluation and management can result in a favourable outcome. Cardiovascular dysfunction and remodelling is a central feature of IUGR. The aim of the study was to use the left modified myocardial performance index (MPI), assess cardiac function in foetuses with intrauterine growth restriction (IUGR) compared to healthy foetuses, and to connect the relationship between changes in MPI and perinatal outcome. A prospective study was conducted with 60 singleton foetuses between 24 and 40 weeks of gestation without foetal chromosomal abnormalities or major malformations, divided into two groups: 30 women with intrauterine growth restriction (30 women) and another 30 women with normal pregnancies (foetal growth pattern appropriate for gestational age and normal heart findings with normal sinus rhythm) who were matched for gestational age and served as the controls. Trans-abdominal ultrasound examination was done with 3.5–7-MHz curvilinear Probe (GE Medical US equipment). The umbilical arteries, middle cerebral artery, and ductus venosus all had blood flow velocity waveforms recorded. The pulsatility index (PI), cerebroplacental ratio (CPR), and Doppler velocimetry (DV) of the umbilical artery were all measured. All foetuses had their myocardial performance index assessed. Normal and abnormal umbilical artery(UA) Doppler, as well as normal and abnormal MCA Doppler, were used to examine the intrauterine growth restriction group. Foetal growth restrictions (FGR) foetuses' Mod-MPI values were compared to gestation-matched controls. The outcomes of the perinatal period were documented.

Results

Intrauterine growth restriction foetuses with defective umbilical arteries Doppler had a substantially higher mean left myocardial performance index (mean 0.58 SD 0.093) than healthy foetuses (mean 0.45SD 0.070) (P 0.001). When compared to the control group, IUGR foetuses with abnormal left myocardial performance index had a significantly worse perinatal outcome and higher morbidity. When compared to intrauterine growth restriction foetuses with normal MPI, intrauterine growth restriction foetuses with defective left MPI had a significantly worse perinatal outcome (whether the UA Doppler was normal or abnormal). Based on the perinatal result, the foetal myocardial performance index was linked to the severity of foetal impairment in intrauterine growth restriction foetuses.

Conclusion

MPI has the potential to be a useful technique for evaluating IUGR pregnancies and predicting neonatal outcome. Within the IUGR foetuses, MPI foetal echocardiographic characteristics can define a high-risk group.

Fetal growth restriction and neonatal-pediatric lung diseases: Vascular mechanistic links and therapeutic directions

Bronchopulmonary dysplasia (BPD) is the most common respiratory sequela of prematurity, and infants born with fetal growth restriction (FGR) are disproportionately represented in BPD statistics, as factors which affect somatic growth may also affect pulmonary growth. Effects of in-utero hypoxia underlying FGR on lung parenchymal architecture predisposing to BPD are well documented, but the pulmonary vascular constructs are not well appreciated. Disruption of angiogenesis during critical periods of lung growth impairs alveolarization, contributing to BPD pathogenesis. Pulmonary artery thickness/stiffness has been noted in FGR in the initial postnatal weeks, and also in well-grown infants with established BPD. The lack of waveform cushioning by the major arteries exposes the pulmonary resistance vessels to higher pulsatile stress, thereby accelerating microvascular disease. Reactive oxygen species, increased sympathetic activity and endothelial dysfunction are common mediators in FGR and BPD; each putative targets for prevention and/or therapeutics using interleukin (IL)-1 receptor antagonist (IL-1Ra), melatonin or inhibition of renin-angiotensin-aldosterone system. While BPD is the archetypal respiratory disease of infancy, effects of FGR on pulmonary function are long-term, extending well into childhood. This narrative links FGR in very/extremely preterm infants with BPD through the vascular affliction as a mechanistic and potentially, therapeutic pathway. Our objectives were to depict the burden of disease for FGR and BPD amongst preterm infants, portray vascular involvement in the placenta in FGR and BPD cohorts, provide high resolution vascular ultrasound information in both cohorts with a view to address therapeutic relevance, and lastly, link this information with paediatric age-group lung diseases.

Preeclampsia and Fetal Growth Restriction as Risk Factors of Future Maternal Cardiovascular Disease-A Review

Cardiovascular diseases (CVDs) remain the leading cause of death in women worldwide. Although traditional risk factors increase later-life CVD, pregnancy-associated complications additionally influence future CVD risk in women. Adverse pregnancy outcomes, including preeclampsia and fetal growth restriction (FGR), are interrelated disorders caused by placental dysfunction, maternal cardiovascular maladaptation to pregnancy, and maternal abnormalities such as endothelial dysfunction, inflammation, hypercoagulability, and vasospasm. The pathophysiologic pathways of some pregnancy complications and CVDs might be linked. This review aimed to highlight the associations between specific adverse pregnancy outcomes and future CVD and emphasize the importance of considering pregnancy history in assessing a woman's CVD risk. Moreover, we wanted to underline the role of maternal cardiovascular maladaptation in the development of specific pregnancy complications such as FGR.

Human placental gene sets improve analysis of placental pathologies and link trophoblast and cancer invasion genes

INTRODUCTION

Interpretation of gene expression uses set enrichment or overrepresentation methods that depend on sets of annotated genes, such as the popular Gene Ontology. The placenta is understudied relative to other major organs creating a deficit of molecular and functional knowledge about this organ. The lack of placental and trophoblast research significantly impacts our ability to interpret the results of high throughput experiments.

METHODS

Gene sets were generated by a semi-automated re-analysis of 330 microarray and 91 RNA sequencing experiments involving placental and trophoblast samples, excluding those related to pathology. Microarray data was obtained from the Gene Expression Omnibus and processed using the R package limma. RNA-sequencing data was extracted from the short read archive and processed using Kallisto and limma. The workflow consisted of quality control for experimental design and data. Sets were generated by pairwise differential expression with a maximum of 200 genes per set.

RESULTS

We created 235 human placenta and trophoblast specific gene sets and found unique subnetworks relative to Gene Ontology. We applied these new placental gene sets to the investigation of preeclampsia and fetal growth restriction as well as invasive tumors and cell models finding matching terms related to cell types and oxygen tension (hypoxia).

DISCUSSION

The human placental gene sets provide an improved context for interpretation of high throughput gene expression studies on placental pathologies beyond the Gene Ontology. Significant enrichment of placental gene sets to cancer samples and cell models indicates a utility beyond applications to placental and trophoblast cells.

Impact of Acute and Chronic Hypoxia-Ischemia on the Transitional Circulation

The transition from intrauterine life to extrauterine existence encompasses significant cardiorespiratory adaptations. These include rapid lung aeration and increase in pulmonary blood flow (PBF). Perinatal asphyxia and fetal growth restriction can severely hamper this transition. Hypoxia is the common denominator in these 2 disease states, with the former characterized by acute insult and the latter by utero-placental insufficiency and a chronic hypoxemic state. Both may manifest as hemodynamic instability. In this review, we emphasize the role of physiologic-based cord clamping in supplementing PBF during transition. The critical role of lung aeration in initiating pulmonary gas exchange and increasing PBF is discussed. Physiologic studies in animal models have enabled greater understanding of the mechanisms and effects of various therapies on transitional circulation. With data from sheep models, we elaborate instrumentation for monitoring of cardiovascular and pulmonary physiology and discuss the combined effect of chest compressions and adrenaline in improving transition at birth. Lastly, physiologic adaptation influencing management in human neonatal cohorts with respect to cardiac and vascular impairments in hypoxic-ischemic encephalopathy and growth restriction is discussed. Impairments in right ventricular function and vascular mechanics hold the key to prognostication and understanding of therapeutic rationale in these critically ill cohorts. The right ventricle and pulmonary circulation seem to be especially affected and may be explored as therapeutic targets. The role of comprehensive assessments using targeted neonatal echocardiography as a longitudinal, reliable, and easily accessible tool, enabling precision medicine facilitating physiologically appropriate treatment choices, is discussed.

Expression and DNA Methylation Status of the Imprinted Genes PEG10 and L3MBTL1 in the Umbilical Cord Blood and Placenta of the Offspring of Assisted Reproductive Technology

The aim of this study is to investigate the expression and DNA methylation status of the imprinted genes PEG10 and L3MBTL1 in the offspring of assisted reproductive technology (ART). The ART group consists of 30 cases of placenta and umbilical cord blood from ART full-term, uncomplicated singleton pregnancy progeny, and the normal control group consists of 30 cases of placenta and umbilical cord blood from natural full-term, uncomplicated singleton pregnancy progeny. The imprinted genes PEG10 and L3MBTL1 are analyzed, and the expression and methylation status of the two genes are detected using real-time quantitative polymerase chain reaction (QRT-PCR), immunohistochemistry (IHC), Western blotting (WB), and methylation-specific polymerase chain reaction (MSP). Compared with the normal control group, the PEG10 mRNA relative quantity (RQ) value in the placenta is 0.994 ± 0.458, with its RQ value up-regulated (P = 0.015). The PEG10 mRNA RQ value in the umbilical cord blood is 0.875 ± 0.452, with its RQ value up-regulated (P = 0.002). However, the L3MBTL1 mRNA RQ value in the placenta is 0.404 ± 0.234, with its RQ value down-regulated (P = 0.024). The L3MBTL1 mRNA RQ value in the umbilical cord blood is 0.337 ± 0.213, and there is no difference in the umbilical cord blood (P = 0.081). Compared with the normal control group, the expression of PEGl0 protein in the placenta of the ART progeny is up-regulated (P = 0.000), while the expression of L3MBTLl protein is down-regulated (P = 0.000). The methylation status of the PEGl0 promoter region in the placenta in the ART group is lower than that in the normal control group (P = 0.037), and that of the promoter region of the umbilical cord blood is lower than that of the natural pregnancy group (P = 0.032). The methylation status of the L3MBTLl promoter region is higher in the placenta than in the normal control group (P = 0.038), and there is no difference between the two groups in the umbilical cord blood (P = 0.301). In the ART group, the values of PEGl0 and L3MBTLl RQ in the placenta and the umbilical cord blood of the hypermethylated group are lower than in those of the hypomethylated group. ART may increase the risk of the abnormal expression of PEG10 and L3MBTL1 in offspring imprinted genes. The methylation of the promoter region may be the mechanism that regulates the expression of PEGl0 and L3MBTL1.

Formulating a Meaningful and Comprehensive Placental Phenotypic Classification

INTRODUCTION

While many placental lesions have been identified and defined, the significance of multiple overlapping lesions has not been addressed. The purpose of our analysis was to evaluate overlapping patterns of placental pathology and determine meaningful phenotypes associated with adverse birth outcomes.

METHODS

Placental pathology reports were obtained from a single hospital between 2009 and 2018. Placental lesions were grouped into four major categories: acute inflammation (AI), chronic inflammation (CI), maternal vascular malperfusion (MVM), and fetal vascular malperfusion (FVM). Within each category, lesions were classified as not present, low grade or high grade. Combinations of pathologies were evaluated in relation to preterm birth (<37 weeks) and small for gestational age (SGA) infant (birthweight <10th percentile).

RESULTS

During the study period, 19,027 placentas were reviewed by pathologists. Results from interaction models indicate that MVM and MVM in combination with CI and/or FVM are associated with the greatest odds of SGA infant and PTB. When incorporating grade, we identified 21 phenotype groups, each with characteristic associations with the SGA infant and patterns of PTB.

DISCUSSION

We have developed a comprehensive and meaningful placental phenotype that incorporates severity and multiplicity of placental lesions. We have also developed a web application to facilitate phenotype determination (https://placentaexpression.shinyapps.io/phenotype).