Síndrome de transfusão feto-fetal: revisão de literatura / Twin-twin transfusion syndrome: a literature review

A síndrome de transfusão feto-fetal é uma complicação das gestações gemelares monocoriônicas. Além de ocorrer comumente no segundo trimestre, apresenta elevada morbimortalidade fetal e neonatal, e taxas de incidência que variam de 10 a 15% dentre todas as gravidezes monocoriônicas. O objetivo deste estudo é realizar uma revisão de literatura a partir de levantamento bibliográfico acerca dos principais aspectos epidemiológicos, clínicos e terapêuticos da STFF. A base de dados PubMed foi consultada, uma vez que os termos de pesquisa utilizados foram "síndrome de transfusão feto-fetal", "diagnóstico" e "tratamento". Obtiveram-se sessenta e oito artigos de revisão de literatura e/ou revisão sistemática, sendo que apenas vinte e nove foram selecionados após aplicação dos critérios de elegibilidade. Em relação à fisiopatologia, a síndrome é explicada pela transferência sanguínea direta entre os fetos gemelares através de anastomoses arteriovenosas placentárias, conceitualmente determinando a existência de um feto receptor e outro doador. Embora as gestantes comumente se apresentam assintomáticas, as repercussões clínicas fetais costumam ser graves. O diagnóstico é exclusivamente ultrassonográfico e deve ser feito o mais precocemente possível, ressaltando-se a importância da detecção da corionicidade da gestação gemelar, além de acompanhamento ultrassonográfico seriado para rastreio do desenvolvimento da síndrome. Apesar de ainda não haver protocolo de tratamento bem estabelecido, a ablação dos vasos placentários a laser é tida como o padrão-ouro dentre as opções terapêuticas disponíveis. Apresenta elevada taxa de sobrevida de pelo menos um dos fetos e baixos índices de sequelas neurológicas neonatais, podendo ser realizada somente até a 26ª semana de gestação.

Twin-twin transfusion syndrome is a complication of monochorionic twin pregnancies. In addition to commonly occurring in the second trimester, it has high fetal and neonatal morbidity and mortality and incidence rates ranging from 10 to 15% among all monochorionic pregnancies. This study aims to perform a literature review based on a bibliographic survey about the main epidemiological, clinical and therapeutic aspects of TTTS. The PubMed database was consulted, as the search terms used were "twin-twin transfusion syndrome", "diagnosis", and "treatment". Sixty-eight literature review and systematic review articles were obtained, and only twenty-nine were selected after applying the eligibility criteria. About the pathophysiology, the syndrome is explained by direct blood transfer between the twin fetuses through placental arteriovenous anastomoses, determining the existence of a recipient fetus and another donor. Although pregnant women are usually asymptomatic, the clinical fetal repercussions are often severe. Diagnosis is exclusively ultrasonographic and must be made as early as possible, emphasizing the importance of detecting chorionicity in twin pregnancy, in addition to serial ultrasonographic follow-up to track the development of the syndrome. Although there is still no well-established treatment protocol, endoscopic laser ablation of vascular anastomoses is considered the gold standard among the available therapeutic options. It has a high survival rate for at least one of the fetuses and low rates of neonatal neurological sequelae and can only be performed until the 26th week of pregnancy.

Performance of conventional cytogenetic analysis on chorionic villi when only one cell layer, cytotrophoblast or mesenchyme alone, is analyzed.

OBJECTIVE: To provide an estimation of the probability of error when chorionic villi (CV) cytogenetic analysis is limited to a single placental layer; either a direct preparation (Dir) or long-term culture (LTC). METHODS: We retrospectively reviewed cytogenetic studies on 81,593 consecutive CV samples in which both Dir and LTC were analyzed. All mosaic cases received amniocentesis. The false omission and false discovery rates were calculated by assessing the results that would have been reported when analysis was limited to either Dir or LTC. RESULTS: For all abnormalities combined, the proportion of normal Dir or LTC only reports that would have been inconsistent with a subsequent amniocentesis was 0.09% and 0.03%, respectively (false omissions). Among abnormal reports based on Dir or LTC alone, 8.01% and 3.17%, respectively, would be inconsistent with a subsequent amniocentesis result (false discoveries). Differences are present for individual abnormalities. CONCLUSIONS: From the perspective of identifying all abnormalities of potential clinical significance, the analysis of both placental layers is optimal. LTC alone is the preferred approach if only one layer of placenta is to be analyzed. Although rare, it is important to acknowledge that one cell layer analysis alone can cause misdiagnosis due to undetected mosaicism.

Placental delayed villous maturation is associated with evidence of chronic fetal hypoxia.

Background Normal development of the human placenta, referred to as villous tree maturation, entails formation of the vasculosyncytial membranes. These structures develop by the approximation of syncytiotrophoblasts with the villous capillary endothelium and constitute the most efficient sites of gaseous exchange in the placenta. Defective maturation of the villous tree can lead to deficient vasculosyncytial membranes, implicated in the high incidence of hypoxic complications. Hypoxia, in turn, can stimulate production of erythropoietin, whereby increased fetal plasma or amniotic fluid concentrations of this hormone reflect fetal hypoxemia. The current study was undertaken to determine whether delayed villous maturation is associated with changes in amniotic fluid erythropoietin concentrations. Methods Placental histologic examination was performed using hematoxylin and eosin. Subsequent to histologic assessment of delayed villous maturation, the diagnosis was confirmed with CD-15 immunohistochemistry. The controls (n = 61) were pregnancies without villous maturation abnormalities, and cases (n = 5) were pregnancies with delayed villous maturation. Amniotic fluid erythropoietin concentrations were measured using a specific immunoassay. Results Concentrations of erythropoietin in the amniotic fluid (1) of controls were less than the limit of detection and (2) of cases with delayed villous maturation were significantly higher than those of controls (P-value = 0.048). Conclusion Delayed villous maturation is associated with higher concentrations of amniotic fluid erythropoietin.

The placenta in fetal growth restriction: What is going wrong?

The placenta is essential for the efficient delivery of nutrients and oxygen from mother to fetus to maintain normal fetal growth. Dysfunctional placental development underpins many pregnancy complications, including fetal growth restriction (FGR) a condition in which the fetus does not reach its growth potential. The FGR placenta is smaller than normal placentae throughout gestation and displays maldevelopment of both the placental villi and the fetal vasculature within these villi. Specialized epithelial cells called trophoblasts exhibit abnormal function and development in FGR placentae. This includes an altered balance between proliferation and apoptotic death, premature cellular senescence, and reduced colonisation of the maternal decidual tissue. Thus, the placenta undergoes aberrant changes at the macroscopic to cellular level in FGR, which can limit exchange capacity and downstream fetal growth. This review aims to compile stereological, in vitro, and imaging data to create a holistic overview of the FGR placenta and its pathophysiology, with a focus on the contribution of trophoblasts.

Evaluation of two aneuploidy screening tests for chorionic villus samples: Multiplex ligation-dependent probe amplification and fluorescence in situ hybridization.

The vast majority of first-trimester pregnancy losses are the consequence of numerical aberrations in fetal chromosomes, which may involve nearly all chromosomes. Although commercial probes for all chromosomes are available for multiplex ligation-dependent probe amplification (MLPA) and fluorescence in situ hybridization (FISH) analyses, their use has rarely been reported for screening all 24 chromosomes for early fetal demise, especially by FISH. Here, we validated the ability of MLPA and FISH techniques as two low-cost aneuploidy screening methods for 24 chromosomes in 165 chorionic villus samples (CVSs). The results obtained by two methods were compared by the Chi-square test and the Kappa agreement test. Both methods gave conclusive results for all CVSs tested and showed highly consistent results (kappa = 0.890, p < 0.001). There was no statistically significant difference between the aneuploidy rate of the CVSs tested by the two methods (p = 0.180). Most of the samples showed fully concordant molecular karyotyping results (81.21%) between the two analytical methods, 10.91% had incompletely concordant results, and 7.88% had discordant results. The inconsistencies included segmental abnormalities, mosaicism, and polyploidy. Both assays used to screen 24 chromosomes were powerful techniques for detecting aneuploidy in CVSs. In terms of cost-effectiveness and diagnostic accuracy, the combination of subtelomeric (P036, P070) and centromeric (P181) MLPA assays is the better analytic strategy and follow-up analysis by FISH is recommended for MLPA-negative samples.

Hydatidiform molar pregnancy following assisted reproduction.

INTRODUCTION: The use of assisted reproduction techniques (ART) is increasing; however, reports of molar pregnancy following ART remain scarce. Currently, the Human Fertility and Embryology Authority (HFEA) collates data on the molar pregnancies that have resulted through the use of ART. Recently, they have indicated that they will no longer collect these data. AIM: This paper aimed to examine the incidence of molar pregnancy amongst patients undergoing assisted reproduction. METHODS: We contacted HFEA and placed a request under the Freedom of Information Act (2000) for the number of molar pregnancies that resulted from fresh/frozen embryo transfer since HFEA started collecting data in 1991 to February 2018. We also asked how many patients who had suffered a molar pregnancy went on to have a normal pregnancy and how many had subsequent molar pregnancies, in subsequent treatment cycles. RESULTS: Between 68 and 76 molar pregnancies occurred within this period using ART (n = 274,655). The incidence of molar pregnancy using fresh intracytoplasmic sperm injection (ICSI) (1/4302) and fresh in vitro fertilisation (IVF) (1/4333) was similar. The risk of recurrence of molar pregnancy following a previous molar was higher following ART compared to spontaneous conceptions. CONCLUSION: The use of ICSI should be protective against triploidy; however, the retrospective data suggests that molar pregnancy is not eliminated with the use of ART. It is pertinent to continue to record this data, through the gestational trophoblastic disease centres, in order to ensure no further increase in incidence, appropriate follow-up, and transparency in communication.

Pathophysiology of placental-derived fetal growth restriction.

Placental-related fetal growth restriction arises primarily due to deficient remodeling of the uterine spiral arteries supplying the placenta during early pregnancy. The resultant malperfusion induces cell stress within the placental tissues, leading to selective suppression of protein synthesis and reduced cell proliferation. These effects are compounded in more severe cases by increased infarction and fibrin deposition. Consequently, there is a reduction in villous volume and surface area for maternal-fetal exchange. Extensive dysregulation of imprinted and nonimprinted gene expression occurs, affecting placental transport, endocrine, metabolic, and immune functions. Secondary changes involving dedifferentiation of smooth muscle cells surrounding the fetal arteries within placental stem villi correlate with absent or reversed end-diastolic umbilical artery blood flow, and with a reduction in birthweight. Many of the morphological changes, principally the intraplacental vascular lesions, can be imaged using ultrasound or magnetic resonance imaging scanning, enabling their development and progression to be followed in vivo. The changes are more severe in cases of growth restriction associated with preeclampsia compared to those with growth restriction alone, consistent with the greater degree of maternal vasculopathy reported in the former and more extensive macroscopic placental damage including infarcts, extensive fibrin deposition and microscopic villous developmental defects, atherosis of the spiral arteries, and noninfectious villitis. The higher level of stress may activate proinflammatory and apoptotic pathways within the syncytiotrophoblast, releasing factors that cause the maternal endothelial cell activation that distinguishes between the 2 conditions. Congenital anomalies of the umbilical cord and placental shape are the only placental-related conditions that are not associated with maldevelopment of the uteroplacental circulation, and their impact on fetal growth is limited.

Towards standardized criteria for diagnosing chronic intervillositis of unknown etiology: A systematic review.

Chronic intervillositis of unknown etiology (CIUE) is a poorly understood, relatively rare condition characterized histologically by the intervillous infiltration of mononuclear cells in the placenta. Clinically, CIUE is associated with poor pregnancy outcome (e.g., impaired fetal growth, preterm birth, fetal death) and high risk of recurrence in subsequent pregnancies. Because CIUE is not defined consistently, it is essential to clearly define this condition. We therefore review the published definitions of CIUE. In addition, we provide an overview of the reviewed histopathological and maternal characteristics, obstetric features, and pregnancy outcomes. Medical publication databases were searched for articles published through February 2017. Eighteen studies were included in our systematic review. The sole inclusion criterion used in all studies was the presence of intervillous infiltrates. Overall, CIUE was characterized by adverse pregnancy outcome. Miscarriage occurred in 24% of cases, with approximately half of these miscarriages defined as late. Impaired growth was commonly observed, 32.4% of pregnancies reached term, and the live birth rate was 54.9%. The high recurrence rate (25.1%) of the intervillous infiltrates in subsequent pregnancies underscores the clinical relevance of CIUE, the need for increased awareness among pathologists and clinicians, and the need for further research. Criteria for the diagnosis of CIUE are proposed and a Delphi study could be used to resolve any controversy regarding these criteria. Future studies should be designed to characterize the full clinical spectrum of CIUE.

Expression of MicroRNA-146a and MicroRNA-155 in Placental Villi in Early- and Late-Onset Preeclampsia.

We studied the expression of microRNA-146a and microRNA-155 in placental villi from 18 women (26-39 weeks of gestation) of reproductive age with early- or late-onset preeclampsia. The reference group consisted of women with physiological pregnancy and full-term gestation and with preterm birth after caesarian section on gestation week 26-31. MicroRNA-146a and microRNA-155 were detected by in situ hybridization with digoxigenin on paraffin sections. It was found that the expression of microRNA-146a in both syncytiotrophoblast of the intermediate villi and syncytial knots was lower at late-onset preeclampsia than at physiologic pregnancy of full-term period (p=0.037 and p=0.001 respectively). The expression of microRNA-155 in syncytiotrophoblast of intermediate placental villi in early-onset preeclampsia was higher than in group with preterm delivery (p=0.003). However, in syncytiotrophoblast of intermediate villi and in syncytial knots, the expression of microRNA-155 was lower at late-onset preeclampsia in comparison with full-term physiological pregnancy (p=0.005). In addition, the expression of microRNA-146a and microRNA-155 did not increase in the later terms in preeclampsia, while in the reference groups demonstrating gradual increase in the expression of these markers with increasing gestational age. Expression microRNA-146a and microRNA-155 little differed in early- and late-onset preeclampsia. These findings suggest that different variants of preeclampsia are probably characterized by common pathogenetic pathways. Damaged trophoblast cannot maintain of microRNAs synthesis at the required level, which determines the formation of a vicious circle in preeclampsia and further progression of the disease.

Wnt5a inhibited human trophoblast cell line HTR8/SVneo invasion: implications for early placentation and preeclampsia.

OBJECTIVE: Wnt5a and Wnt signaling play potential roles in human placental and fetal development. The objective of this study is to explore the role of Wnt5a in the invasion of the human trophoblast cell line HTR8/SVneo and the probable mechanism of early placentation and preeclampsia in which Wnt5a is involved. METHODS: Human first trimester villous tissues from normal pregnancies and third trimester placentas from pregnancies with or without preeclampsia (PE) were used in the detection of the expression and subcellular location of Wnt5a. The human trophoblast cell line HTR8/SVneo was treated with 0-400 ng/ml recombinant Wnt5a to investigate the role of Wnt5a in human trophoblast invasion. RESULTS: Human first trimester villous is accompanied by the decreased expression of Wnt5a compared with term placenta. Upregulated Wnt5a was detected in PE placenta compared with the normal control. Wnt5a inhibited the migration and invasion of HTR8/SVneo cells with decreased integrin ß1, α5 and N-cadherin. Moreover, Wnt5a downregulated ß-catenin in HTR8/SVneo cells. CONCLUSIONS: These findings strongly suggest that Wnt5a inhibits the invasion of HTR8/SVneo cells. Decreased Wnt5a facilitates early placentation, whereas increased Wnt5a contributes to the pathogenesis of PE with insufficient trophoblast invasion. Aberrant Wnt5a may function by impairing Wnt non-canonical/ß-catenin signaling pathway in trophoblasts.

[Transamination In Syncytiotrophoblast of Placenta Villi in Parturient Women Suffered the Acute Form of CMV Infection at the Third Trimester of Gestation].

AIM: to study the process of proteins transamination in syncytiotrophoblast of placenta villi of women who suffered the acute form of cytomega- lovirus (CMV) infection during pregnancy. METHODS: 30 pregnant women with CMV infection recurrence at the 25-28th week of pregnancy were examined. The activity of γ-glutamyltransferase in the peripheral blood of pregnant women was determined by spectrophotometry at the device "Stat-Fax-2100" (The USA). Hsp-70 and caspase-3 in placenta homogenate were found out with serological methods. The activity of glutamatdehydrogenase and pyridoxal-5-phosphatase was studied with histochemical method of Z. Loyd at the placenta slice of parturient women. The apoptotic changes in syncytiotrophoblast nuclei were defined by ISEL-method. RESULTS. The peripheral blood of CMV-seropositive parturient women showed a reduction of γ-glutamyltransferase in 1.30 times. Histochemically we identified the reduction of reaction products' concentration in response to pyridoxal-5-phosphate by 2.14 times, to glutamatdehydrogenase by 1,57 times. At the same time there was an increase of caspase-3 in 2,8 times and reduction of Hsp70 in 2.6 times in placenta homogenate. The number of apoptotic changes in syncytio-trophoblast nuclei increased by 4 times. CONCLUSION: Worsening of CMV infection in the period 25-28 weeks of pregnancy leads to disruption of amino acid metabolism in the placenta, causing structural and functional and metabolic adjustment, and is one of the reasons for slow growth and lack of development of the fetus.

The possible role of extravillous trophoblast-derived exosomes on the uterine spiral arterial remodeling under both normal and pathological conditions.

A tenet of contemporary obstetrics is that events that compromise placentation increase the risk of complications of pregnancy and contribute to poor pregnancy outcome. In particular, conditions that affect the invasion of placental cells and remodeling of uterine spiral arteries compromise placental function and the subsequent development of the fetus. Extravillous trophoblast cells (EVTs) proliferate and migrate from the cytotrophoblast in the anchoring villi of the placenta and invade the maternal decidua and myometrium. These cells are localised with uterine uterine spiral arteries and are thought to induce vascular remodeling. A newly identified pathway by which EVTs may regulate vascular remodeling within the uterus is via the release of exosomes. Trophoblast cells release exosomes that mediate aspects of cell-to-cell communication. The aim of this brief commentary is to review the putative role of exosomes released from extravillous trophoblast cells in uterine spiral artery remodeling and, in particular, their role in the aetiology of preeclampsia. Placental exosomes may engage in local cell-to-cell communication between the cell constituents of the placenta and contiguous maternal tissues and/or distal interactions, involving the release of placental exosomes into biological fluids and their transport to a remote site of action.

Genome-wide miRNA profiling of villus and decidua of recurrent spontaneous abortion patients.

MicroRNAs (miRNAs) are non-coding RNA molecules of about 22 nucleotides that involved in post-transcriptional gene regulation. Evidence indicates that miRNAs play essential roles in endometriosis, pre-eclampsia, infertility and other reproductive system diseases. However, whether miRNAs are involved in recurrent spontaneous abortion (RSA) is unclear. In this work, we analysed the miRNA expression profiles in six pairs of villus or decidua from RSA patients and normal pregnancy (NP) women using a human miRNA microarray. Some of the chip results were confirmed by RT-qPCR. In the villi of RSA patients, expression of hsa-miR-184, hsa-miR-187 and hsa-miR-125b-2 was significantly higher, while expression of hsa-miR-520f, hsa-miR-3175 and hsa-miR-4672 was significantly lower, comparing with those of NP control. As well, a total of five miRNAs (hsa-miR-517c, hsa-miR-519a-1, hsa-miR-522, hsa-miR-520h and hsa-miR-184) were upregulated in the decidua of RSA patients. The target genes of these differentially expressed miRNAs were predicted by miRWalk, and we speculate a network of miRNA regulating RSA by target genes function on adhesion, apoptosis and angiogenesis. Our study may help clarify the molecular mechanisms which are involved in the progression of RSA, and provide a reference for future research.

Placental leptin in HIV-associated preeclampsia.

OBJECTIVE: HIV-associated preeclampsia reflects a combination of opposing influences on the immune status. The adipocyte hormone leptin has been implicated in the pathophysiology of preeclampsia and in enhancing immunity. This study is the first, to our knowledge, to determine whether leptin levels in the placenta differ between HIV-associated normotensive and preeclamptic pregnancies. The study also compares leptin levels between the exchange and conducting areas of the placenta. STUDY DESIGN: Pregnant women were recruited antenatally and grouped as follows: normotensive HIV uninfected (n=30), normotensive HIV infected (n=60), preeclamptic HIV uninfected (n=30) and preeclamptic HIV infected (n=60). Anthropometric data were collected and placental leptin was analysed by immunohistochemistry and ELISA. RESULTS: Leptin levels were similar in the central and peripheral regions of the placenta. Leptin immunoreactivity was observed amongst the different trophoblast cell populations. Both ELISA and immunohistochemistry of the placental exchange villi indicated that leptin levels were higher in preeclampsia compared to normotensive pregnancies (p<0.001). HIV status had no effect on leptin levels but levels were higher in participants on highly active antiretroviral treatment (HAART) compared to those on prophylaxis for prevention of mother to child transmission (PMTCT) with normotensive (p=0.006) and preeclamptic (p=0.002) pregnancies. The area of immunostaining was greater in the exchange compared to the conducting villi in HIV infected and uninfected preeclampsia. CONCLUSIONS: This novel study establishes an elevation of leptin in preeclamptic placentae, irrespective of HIV status. Leptin elevation was not focal in that it occurred in both central and peripheral regions of the preeclamptic placenta. This suggests a role of leptin in the pathophysiology of preeclampsia.

Angiogenesis in villous chorangiosis observed by ultrastructural studies.

Chorangiosis is microscopically designated as more than ten terminal capillaries within the villous stroma of the placenta and is mostly related to chronic fetal hypoxia. However, the histogenetic relationship between increased number of terminal villous capillaries and chronic hypoxia has not yet been clarified. Of 665 placentas histologically examined at Saitama Medical University from 2003 to 2010, chorangiosis was found in 58 cases (8.7 %), which were mostly more than 35 gestational weeks. In addition, low birth weight (less than 2,500 g) infants (74.1 %) and those who suffered from cardiac anomalies, chromosome anomalies, and single umbilical artery comprised 32.7 % of cases. Placental lesions were associated with chorangiosis involved in infarct (46.6 %), intervillous thrombosis (20.7 %), and marginal hemorrhages (22.4 %). Scanning electron microscopic studies showed narrowing of vessel ostium and disorders of endothelium in the umbilical cord vessel complicated by chorangiosis. Furthermore, in transmission electron microscopic observation, not only the chorionic villi had multiple enlarged vessels within the villous stroma, but we also found that new capillaries were formed by angiogenesis with endothelial cells derived from fibroblasts under the chronic hypoxic state.

The role of the invasive, placental trophoblast in human pregnancy.

During early pregnancy the placenta-derived extravillous trophoblast starts to invade the maternal uterus in order to regulate adequate blood flow and nutrient supply to the growing fetus. A unique set of events including plugging and remodelling of maternal vessels, regulation of oxygen levels, as well as the crosstalk with maternal decidual cells are thought to be precisely controlled by the invading extravillous trophoblasts. However, defects in these processes can lead to severe complications during pregnancy threatening the well-being of both the mother and the developing fetus. For instance incomplete trophoblast-associated invasion and arterial remodelling are associated with preeclampsia, the most common pregnancy-related complication. Moreover, failure in proper placental development and adequate fetal nutrition could be effective later in life, as growth-restricted neonates have a higher risk to develop adult onset of hypertension, heart disease and diabetes mellitus. Consequently, a detailed understanding of the mechanisms that underlie trophoblast invasion is thought to improve both diagnosis and treatment of various pregnancy-related disorders.

Effect of human cytomegalovirus on invasive capability of early pregnant extravillous cytotrophoblasts.

The effect of human cytomegalovirus (HCMV) on invasive capability of early pregnant extravillous cytotrophoblasts (EVTs) was investigated in vitro. Primary EVTs were obtained by complex phosphoesterasum digestion and gradient centrifugation from villous tissue aseptically taken from healthy pregnant women. Cytokeratin7 (CK7), vimentin (Vim) and c-erbB-2 were immunocytochemically detected to identify source of cells, and HCMVpp65 antigen was assayed to determine the infection state of primary EVTs by immunocytochemical staining. The EVTs were divided into two groups: control group and HCMV group, and the expression of c-erbB-2, matrix metalloproteinase-2 (MMP-2) and MMP-9 proteins was detected in two groups by immunocytochemistry and Western blotting. Enzymic activity changes of MMP-2 and MMP-9 were tested by gelatin zymography in primary EVTs infected with HCMV. The invasion of primary EVTs was detected by cell invasion assay in vitro after they were infected by HCMV. The cell source identification showed that the cells obtained were highly-pure primary EVTs, and primary EVTs could be infected by HCMV. Primary EVTs could express c-erbB-2, MMP-2 and MMP-9 proteins, and as compared with control group, the protein expression was decreased significantly in HCMV groups (P<0.05). Primary EVTs could secrete active MMP-2 and MMP-9 in vitro, and the activity of two MMPs was decreased significantly in HCMV groups (P<0.05). The in vitro cell invasion assay showed that the number of primary EVTs permeating Matrigel in HCMV group was decreased (P<0.05). We are led to conclude that HCMV can infect primary EVTs and inhibit their invasion capability, suggesting that the impaired EVT's invasion capability might be related to the abnormal expression of c-erbB-2, MMP-2 and MMP-9 proteins.

In vitro study on human cytomegalovirus affecting early pregnancy villous EVT's invasion function.

BACKGROUND: Human cytomegalovirus (HCMV) is the most common pathogen in uterus during pregnancy, which may lead to some serious results such as miscarriage, stillbirth, cerebellar malformation, fetus developmental retardation, but its pathogenesis has not been fully explained. The hypofunction of extravillous cytotrophoblast (EVT) invasion is the essential pathologic base of some complications of pregnancy. c-erbB-2 is a kind of oncogene protein and closely linked with embryogenesis, tissue repair and regeneration. Matrix metalloproteinase (MMP) is one of the key enzymes which affect EVT migration and invasion function. The expression level changes of c-erbB-2, MMP-2 and MMP-9 can reflect the changes of EVT invasion function. RESULTS: To explore the influence of HCMV on the invasion function of EVT, we tested the protein expression level changes of c-erbB-2, MMP-2 and MMP-9 in villous explant cultured in vitro infected by HCMV, with the use of immunohistochemistry SP method and western blot. We confirmed that HCMV can reproduce and spread in early pregnancy villus; c-erbB-2 protein mainly expressed in normal early pregnancy villous syncytiotrophoblast (ST) remote plasma membrane and EVT, especially remote EVT cell membrane in villous stem cell column, little expressed in ST proximal end cell membrane and interstitial cells; MMP-2 protein primarily expressed in early pregnancy villous EVT endochylema and rarely in villous trophoblast (VT), ST and interstitial cells; MMP-9 protein largely expressed in early pregnancy villous mesenchyme, EVT and VT endochylema. Compared with control group, the three kinds of protein expression level in early pregnancy villus of virus group significantly decreased (P < 0.05). CONCLUSION: HCMV can infect villus in vitro and cause the decrease of early pregnancy villous EVT's invasion function.

Placental vascularization in early onset small for gestational age and preeclampsia.

The objective was to determine whether chorionic villous vascularization is diminished in cases of early onset (<34 weeks) small for gestational age (SGA) and/or preeclampsia (PE). Placental morphometrical measurements were performed in 4 gestational-age-matched groups complicated by SGA, SGA with PE, PE, and spontaneous preterm delivery without SGA or PE as the reference group. Using a video image analysis system, in randomly selected intermediate and terminal villi, the stromal area and the following villous vascular parameters were manually traced and analyzed: number of total, centrally and peripherally localized vessels, vascular area, and vascular area density. No differences were observed in intermediate and terminal villous vascular area. Preeclampsia was associated with smaller terminal villous stromal area (reference 2299 µm2, SGA 2412 µm2, SGA + PE 2073 µm2, and PE 2164 µm2, P = .011), whereas SGA was associated with an increased terminal villous vascular area density (reference 26.1%, SGA 35.7%, SGA + PE 33.4%, and PE 32.0%, P = .029). Compared with preserved flow, lower terminal villous vascular area density was found in cases with absent or reversed end-diastolic (ARED) umbilical artery flow (39.3% vs. 30.3%, P = .013). These data demonstrate that villous vascularization was not influenced by PE, whereas in terminal villi an increased vascular area density was associated with SGA. Lower terminal villous vascular area density was associated with ARED flow in SGA pregnancies, indicating an increased risk of fetal compromise.