Increased Apoptosis, Altered Oxygen Signaling, and Antioxidant Defenses in First-Trimester Pregnancies with High-Resistance Uterine Artery Blood Flow

Association between abnormal uterine artery pulsatility index and the risk of fetal congenital heart defects: a hospital-based cohort study

To explore the associations between high uterine artery pulsatility index (UtA-PI) values and congenital heart disease (CHD) risk and whether they differed between singleton and multiple pregnancies. This hospital-based cohort study involving 52,047 pregnant women who underwent prenatal examinations from 2012 to 2016. Infants born to the included pregnant women were followed until 42 days after birth to identify those with CHDs. Generalized estimating equations were used to estimate the associations of high right UtA-PI (> 95th percentile) values with maternal preeclampsia and fetal CHDs. Logistic regression analyses were conducted using path analysis models to quantify the effect of high right UtA-PI values on fetal CHD risk. A total of 42,552 women and 43,470 infants (147 with CHDs) were included. Preeclampsia risk was associated with a high right UtA-PI in singleton-pregnant women (adjusted PR, 3.01; 95% CI 2.57-3.52). CHD risk was marginally associated with a high right UtA-PI in singleton-pregnant women (adjusted PR, 2.26, 95% CI 1.03-4.95). Considering only two factors, 96.0% of the fetal CHD risk was mediated by preeclampsia in singleton-pregnant women, while 93.8% of the risk was related to a high right UtA-PI in multiple-pregnant women. A high right UtA-PI was marginally associated with an increased fetal CHD risk in singleton-pregnant women and might play an important role in multiple-pregnant women. Further studies are warranted to confirm these findings given the high loss to follow-up rate.

Status of Oxidative Stress during Low-Risk Labour: Preliminary Data

Pregnancy and childbirth are associated with the forming of reactive oxygen species that generate oxidative stress. Oxidative stress is a factor that may adversely affect the development of the fetus and the course of labour. Monitoring the parameters of oxidative stress can be used to assess the risk of health issues in the course of pregnancy and the condition of the newborn. Therefore, the analysis of oxidative stress in the physiological course of labour is the basis for understanding the role of oxidative stress in the pathogenesis of miscarriages and neonatal health circumstances. The study aimed to assess oxidative stress of mother-child pairs in the venous blood and umbilical cord blood at the time of physiological labour. One hundred and sixty-eight mother-child pairs were recruited to donate the mother’s venous blood in the first stage of labour and the venous umbilical cord blood after the newborn’s birth. Total antioxidant status (TAS), the activity of superoxide dismutase (SOD) with cofactors (Zn, Cu, Mn) and the activity of glutathione peroxidase (GPx) were analysed in venous blood plasma and umbilical cord blood. TAS value (p = 0.034), GPx activity (p < 0.001) and Zn concentration (p = 0.007) were significantly lower in maternal blood plasma as compared to neonatal umbilical cord blood. However, the activity of SOD (p = 0.013) and the concentration of Cu (p < 0.001) were significantly higher in the blood of mothers than of new-borns. The concentration of Mn in the plasma of the mother’s blood and the umbilical cord blood of the newborns was similar. Our research indicates higher levels of antioxidant enzyme (GPx) and total antioxidant potential (TAS) in umbilical cord blood compared to maternal blood, which may suggest depletion of redox reserves in women’s blood during labour.

In utero exposures to mint-flavored JUUL aerosol impair lung development and aggravate house dust mite-induced asthma in adult offspring mice

There are few reports concerning electronic nicotine delivery system (ENDS) use during pregnancy and no studies on asthma in prenatally JUUL-exposed offspring. Here, we tested the hypothesis that in utero JUUL exposure causes unfavorable birth outcomes and lasting pulmonary health effects in adult offspring. BALB/c dams were exposed to either air or mint-flavored JUUL aerosol, 1-hr/d, 20 consecutive days during gestation. Offspring were sacrificed on post-natal day (PND) 0 or at 11-week of age, following house dust mite (HDM) challenge. Gene expression was assessed in the uterine/placental tissue of the dams and lung responses were assessed in offspring at PND0 and at 11 weeks of age. JUUL-exposed offspring exhibited decreased body weights and lengths at PND0. These birth outcomes were accompanied by dysregulation of 54 genes associated with hypoxia and oxidative stress in the uterine/placental tissues of JUUL-exposed dams, as well as 24 genes in the lungs of the offspring related to Wnt signaling, plus 9 genes related to epigenetics, and 7 genes related to inflammation. At 11 weeks of age, JUUL + HDM exposed mice exhibited pulmonary inflammation when compared to their respective air + HDM controls. Additionally, the JUUL + HDM exposure dysregulated several genes associated with allergies and asthma. Further, the JUUL + HDM females showed decreased methylation of the promoter region of the Il10ra gene. Taken together, our mouse model shows that inhalation of JUUL aerosols during pregnancy affects the intrauterine environment, impairs lung development, and heightens the effects of allergic airway responses later in life.

Preeclampsia and Fetal Congenital Heart Defects

Endothelial dysfunction, impaired implantation and placental insufficiency have been identified as mechanisms behind the development of pre-eclampsia, resulting in angiogenic factors' alteration. Angiogenic imbalance is also associated with congenital heart defects, and this common physiologic pathway may explain the association between them and pre-eclampsia. This review aims to understand the physiology shared by these two entities and whether women with pre-eclampsia have an increased risk of fetal congenital heart defects (or the opposite). The present research has highlighted multiple vasculogenic pathways associated with heart defects and preeclampsia, but also epigenetic and environmental factors, contributing both. It is also known that fetuses with a prenatal diagnosis of congenital heart disease have an increased risk of several comorbidities, including intrauterine growth restriction. Moreover, the impact of pre-eclampsia goes beyond pregnancy as it increases the risk for following pregnancies and for diseases later in life in both offspring and mothers. Given the morbidity and mortality associated with these conditions, it is of foremost importance to understand how they are related and its causative mechanisms. This knowledge may allow earlier diagnosis, an adequate surveillance or even the implementation of preventive strategies.

Evaluation and Management of Suspected Fetal Growth Restriction

Impaired fetal growth owing to placental insufficiency is a major contributor to adverse perinatal outcomes. No intervention is available that improves outcomes by changing the pathophysiologic process. Monitoring in early-onset fetal growth restriction (FGR) focuses on optimizing the timing of iatrogenic preterm delivery using cardiotocography and Doppler ultrasound. In late-onset FGR, identifying the fetus at risk for immediate hypoxia and who benefits from expedited delivery is challenging. It is likely that studies in the next decade will provide evidence how to best integrate different monitoring variables and other prognosticators in risk models that are aimed to optimize individual treatment strategies.

The Immediate and Long-Term Impact of Preeclampsia on Offspring Vascular and Cardiac Physiology in the Preterm Infant

Hypertensive disorders of pregnancy, including preeclampsia, affect nearly 10% of all pregnancies and are associated with significant long-term detrimental effects on both maternal and offspring cardiovascular health. Current management of preeclampsia involves timely delivery with the more severe form of disease requiring iatrogenic preterm birth. The effects on the maternal cardiovascular system have been studied extensively; however, less is known about the short- and long-term impacts on offspring cardiovascular health. There is a growing body of evidence suggesting that the offspring of pre-eclamptic pregnancies have an altered cardiac structure and function, along with a unique vascular physiology driven by lower endothelial function. Many of these changes can also be seen in those born preterm even in the absence of pregnancy hypertension. It is difficult to determine the relative contribution of pre-maturity and preeclampsia to the cardiovascular phenotype of those exposed to these pregnancy complications as they are, in many cases, inextricably linked. This review, therefore, focuses specifically on the evidence from clinical studies showing a negative cardiovascular impact of preeclampsia in preterm-born offspring, investigating phenotypic similarities and differences between offspring born preterm to normotensive vs. pre-eclamptic pregnancies. We explore the unique cardiac and vascular alterations in pre-eclamptic offspring born preterm, highlighting knowledge gaps, and potential areas of further research in the field.

Current approaches and developments in transcript profiling of the human placenta

BACKGROUND

The placenta is the active interface between mother and foetus, bearing the molecular marks of rapid development and exposures in utero. The placenta is routinely discarded at delivery, providing a valuable resource to explore maternal-offspring health and disease in pregnancy. Genome-wide profiling of the human placental transcriptome provides an unbiased approach to study normal maternal–placental–foetal physiology and pathologies.

OBJECTIVE AND RATIONALE

To date, many studies have examined the human placental transcriptome, but often within a narrow focus. This review aims to provide a comprehensive overview of human placental transcriptome studies, encompassing those from the cellular to tissue levels and contextualize current findings from a broader perspective. We have consolidated studies into overarching themes, summarized key research findings and addressed important considerations in study design, as a means to promote wider data sharing and support larger meta-analysis of already available data and greater collaboration between researchers in order to fully capitalize on the potential of transcript profiling in future studies.

SEARCH METHODS

The PubMed database, National Center for Biotechnology Information and European Bioinformatics Institute dataset repositories were searched, to identify all relevant human studies using ‘placenta’, ‘decidua’, ‘trophoblast’, ‘transcriptome’, ‘microarray’ and ‘RNA sequencing’ as search terms until May 2019. Additional studies were found from bibliographies of identified studies.

OUTCOMES

The 179 identified studies were classifiable into four broad themes: healthy placental development, pregnancy complications, exposures during pregnancy and in vitro placental cultures. The median sample size was 13 (interquartile range 8–29). Transcriptome studies prior to 2015 were predominantly performed using microarrays, while RNA sequencing became the preferred choice in more recent studies. Development of fluidics technology, combined with RNA sequencing, has enabled transcript profiles to be generated of single cells throughout pregnancy, in contrast to previous studies relying on isolated cells. There are several key study aspects, such as sample selection criteria, sample processing and data analysis methods that may represent pitfalls and limitations, which need to be carefully considered as they influence interpretation of findings and conclusions. Furthermore, several areas of growing importance, such as maternal mental health and maternal obesity are understudied and the profiling of placentas from these conditions should be prioritized.

WIDER IMPLICATIONS

Integrative analysis of placental transcriptomics with other ‘omics’ (methylome, proteome and metabolome) and linkage with future outcomes from longitudinal studies is crucial in enhancing knowledge of healthy placental development and function, and in enabling the underlying causal mechanisms of pregnancy complications to be identified. Such understanding could help in predicting risk of future adversity and in designing interventions that can improve the health outcomes of both mothers and their offspring. Wider collaboration and sharing of placental transcriptome data, overcoming the challenges in obtaining sufficient numbers of quality samples with well-defined clinical characteristics, and dedication of resources to understudied areas of pregnancy will undoubtedly help drive the field forward.

Maternal Angiotensin Increases Placental Leptin in Early Gestation via an Alternative Renin-Angiotensin System Pathway: Suggesting a Link to Preeclampsia

[Figure: see text].

The association of maternal hypertensive disorders with neonatal congenital heart disease: analysis of a United States cohort

OBJECTIVE

To examine the association of any type of maternal hypertensive disorders of pregnancy (HDP) and neonatal congenital heart diseases (CHD).

STUDY DESIGN

We compared the prevalence of CHD between neonates born to mothers with HDP to those delivered to mothers without HDP among 24,525,889 hospital records of living infants, from a national database. We controlled for multiple confounding factors by using multiple logistic regression analysis.

RESULTS

Infants delivered to mothers with HDP had higher prevalence of CHD compared to infants born to mothers without HDP [5.20% vs. 1.47%; aOR: 2.51(2.38-2.64), p < 0.001]. Maternal diabetes was more frequent among infants born to mothers with HDP and was independently associated with CHD [aOR 5.14 (5.04-5.23), p < 0.001].

CONCLUSION

Infants born to mothers with hypertension had almost a threefold increase in CHD compared with those born to mothers without hypertension. Further studies are needed to investigate the underlying mechanism and direction of this association.

Differential gene expression and limited epigenetic dysregulation at the materno-fetal interface in preeclampsia

Despite the many advances made in the diagnosis and management of preeclampsia, this syndrome remains a leading cause of maternal mortality and life-long morbidity, as well as adverse fetal outcomes. Successful prediction and therapeutic intervention require an improved understanding of the molecular mechanisms, which underlie preeclampsia pathophysiology. We have used an integrated approach to discover placental genetic and epigenetic markers of preeclampsia and validated our findings in an independent cohort of women. We observed the microRNA, MIR138, to be upregulated in singleton preeclamptic placentas; however, this appears to be a female infant sex-specific effect. We did not identify any significant differentially methylated positions (DMPs) in singleton pregnancies, indicating that DNA methylation changes in mild forms of the disease are likely limited. However, we identified infant sex-specific preeclampsia-associated differentially methylated regions among singletons. Disease-associated DMPs were more obvious in a limited sampling of twin pregnancies. Interestingly, 2 out of the 10 most significant changes in methylation over larger regions overlap between singletons and twins and correspond to NAPRT1 and ZNF417.

Regulation of stanniocalcin-1 secretion by BeWo cells and first trimester human placental tissue from normal pregnancies and those at increased risk of developing preeclampsia

Stanniocalcin-1 (STC-1) is a multi-functional glycosylated peptide present in the plasma of healthy women postpartum and increased further in pregnancies complicated by preeclampsia. Although the STC-1 gene is expressed by the placenta what regulates its secretion and from which cells at the feto-maternal interface is unknown. Here, we demonstrate for the first time that the syncytiotrophoblast and cytotrophoblast are a major site of STC-1 protein expression in first trimester placental tissue. Further, in response to low oxygen, first trimester chorionic villous tissue from pregnancies at increased risk of developing preeclampsia secreted significantly more STC-1 than normal tissue under the same conditions. Using the human trophoblast cell line BeWo we have shown that low oxygen increased the secretion of STC-1 but it required co-stimulation with the Adenosine-3', 5'-cyclic monophosphate (cAMP) analogue, 8-Bromo adenosine-3', 5'-cyclic monophosphate cAMP (8 Br-cAMP) to reach significance. Inhibition of Hypoxia inducible factor 2α (HIF-2α) and the Phosphatidylinositol-3 kinase (PI3 -Kinase)/AKT/Serum and glucocorticoid-induced kinase-1(SGK-1) pathway resulted in significant inhibition of STC-1 secretion. As both low oxygen and cAMP are known to play a central role in placental function, their regulation of STC-1 points to a potentially important role in the maintenance of a normal healthy pregnancy and we would hypothesize that it may act to protect against prolonged placental hypoxia seen in preeclampsia.

In utero exposures to electronic-cigarette aerosols impair the Wnt signaling during mouse lung development

Currently, more than 9 million American adults, including women of childbearing age, use electronic-cigarettes (e-cigs). Further, the prevalence of maternal vaping now approaching 10% is similar to that of maternal smoking. Little, however, is known about the effects of fetal exposures to nicotine-rich e-cig aerosols on lung development. In this study, we assessed whether in utero exposures to e-cig aerosols compromised lung development in mice. A third-generation e-cig device was used to expose pregnant BALB/c mice by inhalation to 36 mg/mL of nicotine cinnamon-flavored e-cig aerosols for 14-31 days. This included exposures for either 12 days before mating plus during gestation (preconception groups) or only during gestation (prenatal groups). Respective control mice were exposed to filtered air. Subgroups of offspring were euthanized at birth or at 4 wk of age. Compared with respective air-exposed controls, both preconception and prenatal exposures to e-cig aerosols significantly decreased the offspring birth weight and body length. In the preconception group, 7 inflammation-related genes were downregulated, including 4 genes common to both dams and fetuses, denoting an e-cig immunosuppressive effect. Lung morphometry assessments of preconception e-cig-exposed offspring showed a significantly increased tissue fraction at birth. This result was supported by the downregulation of 75 lung genes involved in the Wnt signaling, which is essential to lung organogenesis. Thus, our data indicate that maternal vaping impairs pregnancy outcomes, alters fetal lung structure, and dysregulates the Wnt signaling. This study provides experimental evidence for future regulations of e-cig products for pregnant women and developmentally vulnerable populations.

Uterine Natural Killer Cell Heterogeneity: Lessons From Mouse Models

Natural killer (NK) cells are the most abundant lymphocytes at the maternal-fetal interface. Epidemiological data implicate NK cells in human pregnancy outcomes. Discoveries using mouse NK cells have guided subsequent advances in human NK cell biology. However, it remains challenging to identify mouse and human uterine NK (uNK) cell function(s) because of the dynamic changes in the systemic-endocrinological and local uterine structural microenvironments during pregnancy. This review discusses functional similarities and differences between mouse and human NK cells at the maternal-fetal interface.

Differences in DNA methylation of insulin-like growth factor 2 and cadherin 13 in patients with preeclampsia

OBJECTIVES

In a previous mass spectrometry study of our research group, 25 proteins were found to be differentially expressed in cerebrospinal fluid of patients with preeclampsia compared to controls. The objective of the current study was to investigate DNA methylation of the genes encoding for the former mentioned proteins in an independent dataset.

STUDY DESIGN

In a nested case-control study of the Rotterdam Periconceptional Cohort, placental tissue, umbilical cord white blood cells and human umbilical vein endothelial cells (HUVEC) were obtained of 13 patients with early-onset preeclampsia, 16 patients with late-onset preeclampsia and 83 normotensive controls (27 patients with fetal growth restriction, 20 patients with spontaneous preterm birth and 36 uncomplicated pregnancies). DNA methylation of 783 CpGs in regions of 25 genes was measured.

MAIN OUTCOME MEASURES

DNA methylation of selected candidate genes in early- and late-onset preeclampsia compared to fetal growth restriction, spontaneous preterm birth and uncomplicated controls.

RESULTS

From the 783 CpGs of the 25 selected genes, 15 CpGs were differentially methylated between early-onset preeclampsia and spontaneous preterm birth (3.80 E-5 ≤ p ≤ 0.036). Four CpGs were differentially methylated between early-onset preeclampsia and fetal growth restriction (0.0002 ≤ p ≤ 0.037) and 13 CpGs were differentially methylated between early onset preeclampsia and uncomplicated controls (0.0001 ≤ p ≤ 0.04).

CONCLUSION

Differences in DNA methylation were found in placental tissue, umbilical cord white blood cells and HUVEC of patients with early onset preeclampsia compared to (un)complicated controls, but not in patients with late-onset preeclampsia. The genes showing the largest differential methylation encode insulin-like growth factor 2 binding protein and receptor and cadherin 13.

Expression of ACKR2 in placentas from different types of preeclampsia

OBJECTIVE

The purpose of this study was to investigate the expression of atypical chemokine receptor 2 (ACKR2, D6) in different types of preeclampsia (PE) and its effects on trophoblast proliferation and apoptosis.

METHODS

The subjects were divided into four groups: early-onset PE group (EOPE, n = 30), late-onset PE group (LOPE, n = 30), preterm birth group (PB, n = 30), and normal group (N, n = 30). The expression of ACKR2 in placentas was evaluated using immunohistochemistry, qRT-PCR, and Western blot. The trophoblast cell line JAR was cultured to detect the expression of ACKR2 after simulating hypoxic conditions with cobalt chloride (CoCl₂). The effects on cell proliferation, apoptosis, and expression of the chemokine CCL2 were analyzed after silencing ACKR2 with siRNA.

RESULTS

ACKR2 was decreased in placentas of EOPE and PB groups at the protein and mRNA level，compared to the normal group. No statistical differences were found between EOPE and PB groups, or between LOPE and normal groups. In our in vitro work, we found that the expression of ACKR2 decreased after treatment with 150 μmol/L, 200 μmol/L, and 250 μmol/L of CoCl₂. After ACKR2 was silenced, the degree of cellular proliferation decreased, while apoptosis and CCL2 expression increased.

CONCLUSION

The changes of ACKR2 expression in placentas of PE may be related to gestational weeks. Hypoxia inhibits the expression of ACKR2 in placentas. Abnormal expression of ACKR2 in PE may lead to dysfunction of trophoblast, and ACKR2 is an essential player in the immunoregulation of the placental chemokine CCL2.

Placental bed research: II. Functional and immunological investigations of the placental bed

Research on the placenta as the interface between the mother and the fetus has been undertaken for some 150 years, and in 2 subsequent reviews, we attempted to summarize the situation. In the first part, we described the discovery of unique physiological modifications of the uteroplacental spiral arteries, enabling them to cope with a major increase in blood flow necessary to ensure proper growth of the fetus. These consist of an invasion of the arterial walls by trophoblast and a progressive disappearance of its normal structure. Researchers then turned to the pathophysiology of the placental bed and in particular to its maternal vascular tree. This yielded vital information for a better understanding of the so-called great obstetrical syndromes (preeclampsia, fetal growth restriction, premature labor and delivery, placenta accreta). Systematic morphological investigations of the uteroplacental vasculature showed that preeclampsia is associated with decreased or failed transformation of spiral arteries and the persistence of endothelial and smooth muscle cells in segments of their myometrial portion. Here we report on recent functional investigations of the placental bed, including in situ biophysical studies of uteroplacental blood flow and vascular resistance, and manipulation of uteroplacental perfusion. These new methodologies have provided a novel way of identifying pregnancies in which remodeling is impaired. In animals it is now possible to manipulate uteroplacental blood flow, leading to an enhancement of fetal growth; this opens the way to trials in abnormal human pregnancies. In this second part, we explored a new, extremely important area of research that deals with the role of specific subsets of leukocytes and macrophages in the placental bed. The human first-trimester decidua is rich in leukocytes called uterine natural killer cells. Both macrophages and uterine natural killer cells increase in number from the secretory endometrium to early pregnancy and play a critical role in mediating the process of spiral artery transformation by inducing initial structural changes. It seems therefore that vascular remodeling of spiral arteries is initiated independently of trophoblast invasion. Dysregulation of the immune system may lead to reproductive failure or pregnancy complications, and in this respect, recent studies have advanced our understanding of the mechanisms regulating immunological tolerance during pregnancy, with several mechanisms being proposed for the development of tolerance to the semiallogeneic fetus. In particular, these include several strategies by which the trophoblast avoids maternal recognition. Finally, an important new dimension is being explored: the likelihood that pregnancy syndromes and impaired uteroplacental vascular remodeling may be linked to future maternal and even the child's cardiovascular disease risk. The functional evidence underlying these observations will be discussed.

Preeclampsia: a gestational cardiorenal syndrome

It is generally accepted today that there are two different types of preeclampsia: an early-onset or placental type and a late-onset or maternal type. In the latent phase, the first one presents with a low output/high resistance circulation eventually leading in the late second or early third trimester to an intense and acutely aggravating systemic disorder with an important impact on maternal and neonatal mortality and morbidity; the other type presents initially as a high volume/low resistance circulation, gradually evolving to a state of circulatory decompensation usually in the later stages of pregnancy, with a less severe impact on maternal and neonatal outcome. For both processes, numerous dysfunctions of the heart, kidneys, arteries, veins and interconnecting systems are reported, most of them presenting earlier and more severely in early- than in late-onset preeclampsia; however, some very specific dysfunctions exist for either type. Experimental, clinical and epidemiological observations before, during and after pregnancy are consistent with gestation-induced worsening of subclinical pre-existing chronic cardiovascular dysfunction in early-onset preeclampsia, and thus sharing the pathophysiology of cardiorenal syndrome type II, and with acute volume overload decompensation of the maternal circulation in late-onset preeclampsia, thus sharing the pathophysiology of cardiorenal syndrome type 1. Cardiorenal syndrome type V is consistent with the process of preeclampsia superimposed upon clinical cardiovascular and/or renal disease, alone or as part of a systemic disorder. This review focuses on the specific differences in haemodynamic dysfunctions between the two types of preeclampsia, with special emphasis on the interorgan interactions between heart and kidneys, introducing the theoretical concept that the pathophysiological processes of preeclampsia can be regarded as the gestational manifestations of cardiorenal syndromes.

Preeclampsia: The Relationship between Uterine Artery Blood Flow and Trophoblast Function

Maternal uterine artery blood flow is critical to maintaining the intrauterine environment, permitting normal placental function, and supporting fetal growth. It has long been believed that inadequate transformation of the maternal uterine vasculature is a consequence of primary defective trophoblast invasion and leads to the development of preeclampsia. That early pregnancy maternal uterine artery perfusion is strongly associated with placental cellular function and behaviour has always been interpreted in this context. Consistently observed changes in pre-conceptual maternal and uterine artery blood flow, abdominal pregnancy implantation, and late pregnancy have been challenging this concept, and suggest that abnormal placental perfusion may result in trophoblast impairment, rather than the other way round. This review focuses on evidence that maternal cardiovascular function plays a significant role in the pathophysiology of preeclampsia.

Correlation between central and uterine hemodynamics in hypertensive disorders of pregnancy

OBJECTIVE

Pregnancies affected by a hypertensive disorder (HDP) have increased uterine artery pulsatility index (UtA-PI) compared with that in healthy pregnancies. Women with HDP are also known to have lower cardiac output and increased systemic vascular resistance. The aim of this study was to investigate the relationship between central and uterine hemodynamics in HDP and uncomplicated pregnancy.

METHODS

This was a prospective study of HDP and normotensive control singleton pregnancies presenting at a tertiary referral hospital between January 2012 and December 2017. Paired measurements of maternal hemodynamics, using a non-invasive device (USCOM-1A®), and UtA-PI were performed in the third trimester. HDP pregnancies were divided into preterm (onset < 37 weeks' gestation) and term (onset ≥ 37 weeks). Spearman's rank coefficient was used to assess the correlation between the central and uteroplacental hemodynamics. Regression analysis was performed to assess the association of UtA-PI with independent variables.

RESULTS

We included 231 women with HDP (152 with preterm and 79 with term HDP) and 378 controls with normotensive pregnancy. Compared with controls, women with preterm HDP had significantly lower cardiac output (median (interquartile range (IQR)), 6.0 (5.1-7.2) vs 6.6 (5.8-7.5) L/min; P < 0.001) and significantly higher systemic vascular resistance (median (IQR), 1394 (1189-1670) vs 1063 (915-1222) dynes × s/cm⁵ ; P < 0.001) and UtA-PI (median (IQR), 1.0 (0.75-1.4) vs 0.67 (0.58-0.83); P < 0.001). Conversely, in women with term HDP, there were no significant differences in heart rate, cardiac output or UtA-PI compared with controls (all P > 0.05), while systemic vascular resistance was significantly higher (median (IQR), 1315 (1099-1527) vs 1063 (915-1222) dynes × s/cm⁵ ; P < 0.001). On multiple regression analysis, heart rate, mean arterial pressure and stroke volume were associated significantly with mean UtA-PI (all P < 0.001).

CONCLUSIONS

Differences observed between HDP and normotensive pregnancies in third-trimester UtA resistance are mirrored in the central maternal hemodynamic parameters. Late pregnancy differences in the uteroplacental circulation in preterm and term HDP are an index of maternal cardiovascular function rather than being related to inadequate spiral artery remodeling and impaired placentation. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

p57KIP2‑mediated inhibition of human trophoblast apoptosis and promotion of invasion in vitro

Placental hypoxia serves a role in the early stages of normal pregnancy and is involved in the pathophysiology of preeclampsia. Previously, it was suggested that p57kinase inhibitory protein (KIP)2 regulates the cell cycle during embryogenesis and apoptosis. Recent evidence has indicated that p57KIP2 is increased in preeclamptic placentas and absence of p57KIP2 induces preeclampsia‑type symptoms in rats. However, effects of p57KIP2 on apoptosis under hypoxic conditions remain to be elucidated. In the present study, HTR‑8/SVneo trophoblasts were cultured under hypoxic conditions (2% O2). Knockdown using small interfering (si)RNA and overexpression of p57KIP2 were utilized to explore the biological function of p57KIP2 in apoptosis and cell function in vitro. Furthermore, expression of p57KIP2 and apoptosis were evaluated by western blotting, flow cytometry and TUNEL assays, and the response of trophoblasts to hypoxia and the role of p57KIP2 in trophoblast migration and invasion was assessed. The role of p57KIP2 in the JNK signaling pathway in HTR‑8/SVneo trophoblasts was further studies. In vitro, protein expression of p57KIP2 was increased in HTR‑8/SVneo cells exposed to 2% O2. Exogenous p57KIP2 overexpression significantly decreased the expression of pro‑apoptosis proteins, including p53, Bax and cleaved caspase3, under hypoxic conditions for 24 h. In addition, knockdown of p57KIP2 increased the response to apoptosis following hypoxia for 24 h. The present study revealed that overexpression of p57KIP2 decreased the levels of phosphorylated‑JNK. JNK inhibitor treatment combined with the overexpression of p57KIP2 significantly decreased the levels of apoptosis and increased cell invasion and migration. Taken together, p57KIP2 knockdown significantly increased apoptosis in HTR‑8/SVneo cells exposed to 2% O2, whereas overexpression of p57KIP2 had opposite effects, mediated by the JNK/stress activated protein kinase (SAPK) signaling pathway. The results indicated that hypoxia‑induced expression of p57KIP2 promoted trophoblast migration and invasion by mediating the JNK/SAPK signaling pathway, which is crucial during placentation. These results may provide a novel molecular mechanism to understand the involvement of p57KIP2 in the pathogenesis of preeclampsia.

First trimester placental endothelial cells from pregnancies with abnormal uterine artery Doppler are more sensitive to apoptotic stimuli

Failure of the placental capillary network to develop normally is associated with early onset fetal growth restriction (FGR) and pre-eclampsia (PE). Although the symptoms are observed at term, the problem begins in the first trimester. However, investigations at this clinically relevant time are hindered by difficulties in identifying earlystage pregnancies that are at risk of developing FGR/PE. Using uterine artery Doppler ultrasound in the first trimester as a proxy measure of poor placentation, we have identified pregnancies at increased risk of developing early onset FGR/PE. Placental endothelial cells (PEC) isolated from pregnancies at increased risk of developing FGR/PE grew more slowly and their basal rate of apoptosis was significantly higher than that seen in the normal group. The pro-apoptotic stimulus, TNFα, induced apoptosis in cells from both groups but this was significantly greater in the high risk group. TNF receptor expression was unaffected. Inhibition of nitric oxide (NO) production significantly increased the sensitivity of cells from the normal pregnancies to TNFα but not in the high risk group establishing a functional role for NO in this system. In conclusion, first trimester PEC from pregnancies at increased risk of developing early onset FGR/PE were inherently more sensitive to apoptotic stimuli and this was functionally linked to the synthesis of NO. This may contribute to the poor placental vascular development seen in on going pregnancies.

Oleic acid stimulation of motility of human extravillous trophoblast cells is mediated by stearoyl-CoA desaturase-1 activity

STUDY QUESTION

Do fatty acids regulate development and motility of human extravillous trophoblast cells (EVTs)?

SUMMARY ANSWER

Oleic acid is a promising lipid molecule that has beneficial effects on motility and development of human EVTs.

WHAT IS KNOWN ALREADY

Fatty acid uptake into trophoblast cells is important for maintaining cellular events during pregnancy, but the molecular mechanisms of action of various fatty acids, including trans fatty acids, saturated fatty acids and monounsaturated fatty acids, in EVT cell lines are not clear.

STUDY DESIGN, SIZE, DURATION

Effects of oleic acid, elaidic acid, palmitic acid and stearic acid on HTR8/SVneo cells were assessed in diverse assays in a dose- and time-dependent manner.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Effects of fatty acids on cell proliferation, migration, invasion and apoptosis (Annexin V expression, propidium iodide staining, TUNEL and invasion assays) of HTR8/SVneo cells were determined. Signal transduction pathways in HTR8/SVneo cells in response to fatty acids were determined by Western blot analyses. Regulation of fatty acids on oxidative conditions in EVTs were determined and validated by measurement of production of cellular reactive oxygen species, intracellular concentrations of free Ca2+and lipid peroxidation assays.

MAIN RESULTS AND THE ROLE OF CHANCE

In present study, we confirmed different effects of oleic acid and elaidic acid on migration, invasion, proliferation and apoptosis of the EVT cell line, HTR8/SVneo. We also investigated stearoyl-CoA desaturase-1 (SCD1) to determine if its activity contributed to oleic acid-induced migration of HTR8/SVneo cells. Next, we analyzed cell signaling molecules mediated by oleic acid and elaidic acid treatment, including MAPK and PI3K/AKT pathways in HTR8/SVneo cells. We further established whether selective inhibition of signaling molecules altered the ability of fatty acids to cause changes in migration and proliferation of HTR8/SVneo cells. Last, we examined the regulatory effects of oleic acid and SCD1 on oxidative stress in HTR8/SVneo cells.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

The lack of in vivo animal studies is a major limitation of this research. Effectiveness of oleic acid to stimulate migration of human EVT cells requires further investigation.

WIDER IMPLICATIONS OF THE FINDINGS

Our results suggest that oleic acid can play an important role in promoting invasion of human EVT cell lines while both trans fatty acids and saturated fatty acids are not conducive to normal placentation. This may have implications for the prevention of pre-eclampsia and intrauterine growth restriction.

STUDY FUNDING AND COMPETING INTEREST(S)

This work was supported by a grant from the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (No. HI15C0810) awarded to G.S. and (No. HI17C0929) awarded to W.L. There are no conflicts of interest.

Ophthalmic artery Doppler for prediction of pre-eclampsia: systematic review and meta-analysis

OBJECTIVE

To determine the accuracy of ophthalmic artery Doppler in pregnancy for the prediction of pre-eclampsia (PE).

METHODS

MEDLINE, EMBASE, CINAHL and The Cochrane Library were searched for relevant citations without language restrictions. Two reviewers independently selected studies that evaluated the accuracy of ophthalmic artery Doppler to predict the development of PE and extracted data to construct 2 × 2 tables. Individual patient data were obtained from the authors if available. A bivariate random-effects model was used for the quantitative synthesis of data. Logistic regression analysis was employed to generate receiver-operating characteristics (ROC) curves and obtain optimal cut-offs for each investigated parameter, and a bivariate analysis was employed using predetermined cut-offs to obtain sensitivity and specificity values and generate summary ROC curves.

RESULTS

A total of 87 citations matched the search criteria of which three studies, involving 1119 pregnancies, were included in the analysis. All included studies had clear description of the index and reference tests, avoidance of verification bias and adequate follow-up. Individual patient data were obtained for all three included studies. First diastolic peak velocity of ophthalmic artery Doppler at a cut-off of 23.3 cm/s showed modest sensitivity (61.0%; 95% CI, 44.2-76.1%) and specificity (73.2%; 95% CI, 66.9-78.7%) for the prediction of early-onset PE (area under the ROC curve (AUC), 0.68; 95% CI, 0.61-0.76). The first diastolic peak velocity had a much lower sensitivity (39.0%; 95% CI, 20.6-61.0%), a similar specificity (73.2%; 95% CI, 66.9-78.7%) and a lower AUC (0.58; CI, 0.52-0.65) for the prediction of late-onset PE. The pulsatility index of the ophthalmic artery did not show a clinically useful sensitivity or specificity at any cut-off for early- or late-onset PE. Peak ratio above 0.65 showed a similar diagnostic accuracy to that of the first diastolic peak velocity with an AUC of 0.67 (95% CI, 0.58-0.77) for early-onset PE and 0.57 (95% CI, 0.51-0.63) for late-onset disease.

CONCLUSIONS

Ophthalmic artery Doppler is a simple, accurate and objective technique with a standalone predictive value for the development of early-onset PE equivalent to that of uterine artery Doppler evaluation. The relationship between ophthalmic Doppler indices and PE cannot be a consequence of trophoblast invasion and may be related to maternal hemodynamic adaptation to pregnancy. The findings of this review justify efforts to elucidate the effectiveness and underlying mechanism whereby two seemingly unrelated maternal vessels can be used for the prediction of a disease considered a 'placental disorder'. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Decidual cell regulation of trophoblast is altered in pregnancies at risk of pre-eclampsia

Successful implantation and placentation are dependent on the interaction between decidual stromal cells (DSC) and extravillous trophoblast (EVT) cells. The extent of trophoblast invasion relies on communication between the placenta and maternal decidua. The cyclical process of decidualisation induces a transformation of endometrial fibroblasts to secretory DSC; these secreted products have many functions including the control of trophoblast invasion. Inadequate trophoblast invasion and remodelling of the uterine vessels (the spiral arteries) are associated with pregnancy disorders such as pre-eclampsia. Uterine artery Doppler resistance index (RI) in the first trimester of pregnancy can be used as a proxy measure of remodelling. DSC were isolated from pregnancies with normal (normal RI) or impaired (high RI) spiral artery remodelling. Following isolation, DSC were re-decidualised using cAMP and MPA and secretion of the decidualisation markers IGFBP-1 and prolactin assessed. We examined the impact of DSC-secreted factors on trophoblast cell function, using the EVT cell line SGHPL-4. We demonstrated that DSC exposed to decidual factors were able to re-decidualise in vitro and that the chemoattraction of trophoblasts by DSC is impaired in pregnancies with high RI. This study provides new insights into the role that DSC play in regulating EVT functions during the first trimester of pregnancy. This is the first study to demonstrate that DSC from pregnancies with impaired vascular remodelling in the first trimester secrete factors that inhibit the directional movement of trophoblast cells. This finding may be important in understanding aberrant trophoblast invasion in pregnancies where vascular remodelling is impaired.

Acute Associations Between Outdoor Temperature and Premature Rupture of Membranes

BACKGROUND

Extreme ambient temperatures have been linked to preterm birth. Preterm premature rupture of membranes is a common precursor to preterm birth but is rarely studied in relation to temperature.

METHODS

We linked 15,381 singleton pregnancies with premature rupture of membranes from a nationwide US obstetrics cohort (2002-2008) to local temperature. Case-crossover analyses compared daily temperature during the week preceding delivery and the day of delivery to 2 control periods, before and after the case period. Conditional logistic regression models calculated the odds ratio (OR) and 95% confidence intervals (CIs) of preterm and term premature rupture of membranes for a 1°C increase in temperature during the warm (May-September) and cold (October-April) season separately after adjusting for humidity, barometric pressure, ozone, and particulate matter.

RESULTS

During the warm season, 1°C increase during the week before delivery was associated with a 5% (95% CI, 3%, 6%) increased preterm premature rupture of membranes risk, and a 4% (95% CI, 3%, 5%) increased term premature rupture of membranes risk. During the cold season, 1°C increase was associated with a 2% decreased risk for both preterm (95% CI, 1%, 3%) and term premature rupture of membranes (95% CI, 1%, 3%). The day-specific associations for the week before delivery were similar, but somewhat stronger for days closer to delivery.

CONCLUSIONS

Relatively small ambient temperature changes were associated with the risk of both preterm and term premature of membranes. Given the adverse consequences of premature rupture of membranes and concerns over global climate change, these findings merit further investigation. See video abstract at, http://links.lww.com/EDE/B312.

Role of early second-trimester uterine artery Doppler screening to predict small-for-gestational-age babies in nulliparous women

BACKGROUND

Trophoblastic invasion of the uterine spiral arteries substantially increases compliance to accommodate increased blood flow to the placenta. Failure of this process impedes uterine artery blood flow, and this may be detected by uterine artery Doppler flow studies. However, the clinical utility of uterine artery Doppler flow studies in the prediction of adverse pregnancy outcomes in a general population remains largely unknown.

OBJECTIVE

We sought to determine the utility of early second-trimester uterine artery Doppler studies as a predictor of small-for-gestational-age neonates.

STUDY DESIGN

Nulliparous women with a viable singleton pregnancy were recruited during their first trimester into an observational prospective cohort study at 8 institutions across the United States. Participants were seen at 3 study visits during pregnancy and again at delivery. Three indices of uterine artery Doppler flow (resistance index, pulsatility index, and diastolic notching) were measured in the right and left uterine arteries between 16 weeks 0 days' and 22 weeks 6 days' gestation. Test characteristics for varying thresholds in the prediction of small for gestational age (defined as birthweight <5th percentile for gestational age [Alexander growth curve]) were evaluated.

RESULTS

Uterine artery Doppler indices, birthweight, and gestational age at birth were available for 8024 women. Birthweight <5th percentile for gestational age occurred in 358 (4.5%) births. Typical thresholds for the uterine artery Doppler indices were all associated with birthweight <5th percentile for gestational age (P < .0001 for each), but the positive predictive values for these cutoffs were all <15% and areas under receiver operating characteristic curves ranged from 0.50-0.60. Across the continuous scales for these measures, the areas under receiver operating characteristic curves ranged from 0.56-0.62. Incorporating maternal age, early pregnancy body mass index, race/ethnicity, smoking status prior to pregnancy, chronic hypertension, and pregestational diabetes in the prediction model resulted in only modest improvements in the areas under receiver operating characteristic curves ranging from 0.63-0.66.

CONCLUSION

In this large prospective cohort, early second-trimester uterine artery Doppler studies were not a clinically useful test for predicting small-for-gestational-age babies.

Impaired mitochondrial fusion, autophagy, biogenesis and dysregulated lipid metabolism is associated with preeclampsia

Preeclampsia(PE) is a pregnancy complication that is diagnosed by the new onset of hypertension and proteinuria. The etiology of PE remains unclear; however, growing evidence indicates that mitochondrial impairment contributes to the pathogenesis. Therefore, we aim to investigate the function of mitochondria in the development of PE. The mitochondrial metabolome in preeclamptic (n = 11) and normal (n = 11) placentas were analyzed using Gas chromatography-mass spectrometry (GC-MS). Student's t-tests and receiver operating characteristic (ROC) curves were conducted to determine which mitochondrial metabolites differed significantly between the two groups. The Pathway Activity Profiling (PAPi) R package was used to predict which metabolic pathways were affected by PE. Western blot analysis was performed to identify the candidate proteins which were associated with mitochondrial repair regulation. GC-MS analysis demonstrated that higher levels of 38 metabolites and lower levels of 2 metabolites were observed in the placenta of patients with severe PE (sPE). Five fatty acids had an area under the ROC curve above 90%. Furthermore, we revealed abnormal regulation of mitochondrial dynamics, autophagy, and biogenesis in sPE. Our discoveries indicate that the compromised lipid metabolism in sPE may result from dysfunctional mitochondria, thus revealing new insights into the etiology of the disease.

Strategies for investigating the maternal-fetal interface in the first trimester of pregnancy: What can we learn about pathology?

The pathologies of the pregnancy complications pre-eclampsia (PE) and fetal growth restriction (FGR) are established in the first trimester of human pregnancy. In a normal pregnancy, decidual spiral arteries are transformed into wide diameter, non-vasoactive vessels capable of meeting the increased demands of the developing fetus for nutrients and oxygen. Disruption of this transformation is associated with PE and FGR. Very little is known of how these first trimester changes are regulated normally and even less is known about how they are compromised in complicated pregnancies. Interactions between maternal and placental cells are essential for pregnancy to progress and this review will summarise the challenges in investigating this area. We will discuss how first trimester studies of pregnancies with an increased risk of developing PE/FGR have started to provide valuable information about pregnancy at this most dynamic and crucial time. We will discuss where there is scope to progress these studies further by refining the ability to identify compromised pregnancies at an early stage, by integrating information from many cell types from the same pregnancy, and by improving our methods for modelling the maternal-fetal interface in vitro.

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Pathology of PE/FGR begins in the first trimester.

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Investigating pregnancies with increased risk of PE/FGR is giving valuable information.

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This will improve further with advances in identifying compromised pregnancies.

Utility of Placental Laterality and Uterine Artery Doppler Abnormalities for Prediction of Preeclampsia

OBJECTIVE

To find out whether placental laterality and abnormal uterine artery waveform and resistance index, as determined by antenatal ultrasonography and Doppler, can be used as a predictor for the development of preeclampsia.

METHODS

This prospective observational cohort study was conducted from August 2013 to October 2014. Two hundred and one (201) normotensive, primigravida women with singleton pregnancies attending the antenatal clinics without any high-risk factor for development of hypertension were subjected to ultrasonography at 18-22 weeks of gestation to determine the placenta location. All the subjects with lateral placentas were subjected to Doppler ultrasonography to look for abnormal Doppler waveform and resistance index. They were followed for the development of preeclampsia till 40 weeks of gestation or delivery.

RESULT

Out of the total 201 women, 71 (24.5 %) had laterally located placentas and of them 37 (52 %) developed preeclampsia, while the remaining 130 (75.5 %) had centrally located placentas and of them 14 (10.8 %) developed preeclampsia (p < 0.001). In subjects with lateral placentas alone (n = 33), 2 (6 %) developed preeclampsia while as those with lateral placentas with Doppler abnormality (n = 38), 35 (92 %) developed preeclampsia (p < 0.001). The overall risk of developing preeclampsia with laterally located placenta was 9.27 (odds ratio), and 95 % confidence interval was (4.30-19.98).

CONCLUSION

Pregnant women with lateral placentas are at significant risk for development of preeclampsia. Lateral placentas when associated with uterine artery Doppler abnormality, risk for development of preeclampsia increases significantly as compared to lateral placentas alone.

The role of decidual NK cells in pregnancies with impaired vascular remodelling

The pathologies of the dangerous pregnancy complications pre-eclampsia (PE) and fetal growth restriction (FGR) are established in the first trimester of human pregnancy yet we know little of how this happens. Finely tuned interactions between maternal and placental cells are essential for pregnancy to progress without complications; however, the precise nature of this cross-talk and how it can go wrong are crucial questions that remain to be answered. This review summarises recent studies examining the role played by natural killer cells in regulating normal placentation and remodelling. Their involvement when it is impaired in PE/FGR pregnancies will additionally be discussed.

Imbalance between proliferation and apoptosis-related impaired GPR30 expression is involved in preeclampsia

The proliferation and apoptosis of cells in the placenta play a critical role in preeclampsia (PE) in which estrogen has been implicated via estrogen receptors (ERs). A novel ER, G-protein-coupled receptor 30 (GPR30), has recently been shown to be involved in PE. We investigated the basic levels of proliferation and apoptosis in normal placentae and placentae with PE and compared GPR30 expression levels between the two groups. We demonstrated that low GPR30 expression levels, more apoptosis, and less proliferation were associated with PE. Moreover, our in vitro study showed that both the selective GPR30 agonist G1 and the general ER agonist 17-β-estradiol were able to protect the placenta from hypoxia-reoxygenation injuries, resulting in decreased apoptosis and increased proliferation. Furthermore, this protective effect was abolished by the addition of the selective GPR30 inhibitor G15. These results provide evidence that (1) GPR30 is involved in regulating cell proliferation and apoptosis; (2) pharmacologic upregulation of GPR30 is beneficial for PE management; (3) GPR30 may therefore be an interventional target for pregnancies complicated by PE.

Effect of hypoxia on expression of placental trophoblast cells SATB1 and β-catenin and its correlation with the pathogenesis of preeclampsia

OBJECTIVE

To study the effect of hypoxia on the expression of placental trophoblast cells SATB1 and β-catenin and its correlation with the pathogenesis of preeclampsia.

METHODS

Trophoblastic cell lines HRT8/SVneo were cultured, SATB1 and β-catenin expression and cell biological behavior were determined after hypoxia reoxygenation treatment; cell biological behavior and the expression of related genes were determined after the transfection of SATB1 and β-catenin siRNA; preeclampsia placenta and normal placenta tissues were collected and the expression of SATB1 and β-catenin were determined.

RESULTS

OD value, cell migration rate, mRNA contents of SATB1 and β-catenin of H/R group were significantly lower than those of Nor group, cell apoptosis rate was higher than that of Nor group and the number of invasive cells was less than that of Nor group; OD value and bcl-2 mRNA content of SATB1-siRNA group were lower than those of NC group; cell apoptosis rate as well as Bax, Caspase-3, Caspase-6 and Caspase-9 mRNA contents were higher than those of NC group; cell migration rate as well as CTSB, CTSD, MMP2 and MMP9 mRNA contents of β-catenin-siRNA group were lower than those of NC group; the number of invasive cells was less than that of NC group; the expression levels of SATB1 and β-catenin in preeclampsia placenta tissue were significantly lower than those in normal placenta tissue.

CONCLUSIONS

Hypoxia can inhibit the expression of SATB1 and β-catenin in the pathogenesis of preeclampsia, which can affect the proliferation, apoptosis, migration and invasion of cells.