Acute funisitis of preterm but not term placentas is associated with severe fetal inflammatory response.

Acute funisitis, whose basic pathologic feature is umbilical vasculitis, constitutes a type of fetal inflammatory response to intrauterine infection. In the present study, a comparative analysis was performed between the clinicopathologic profiles of acute funisitis in term and preterm placentas along with measurement of fetal plasma interleukin 6 (IL-6) levels by specific immunoassay to assess the different biologic implications for the fetus. Acute funisitis in preterm placentas showed a significantly higher incidence of umbilical arteritis (P <.000001), higher fetal plasma IL-6 level (P <.0001), and higher prevalence of major perinatal morbidities (P <.0001). To assess the possible variation in fetal cell response to infectious agents according to gestational age, amnion cells and placental villous tissues obtained at different gestational ages were treated with bacterial lipopolysaccharides, and the IL-6 level of the culture media was assayed. Amnion cells and placental villous tissues from preterm placenta showed a more pronounced cytokine response than those from term placenta. The findings of this study indicate that the clinicopathologic significance of acute funisitis in term placentas is different from that of preterm placentas. Furthermore, they indicate that the robust inflammatory response of the fetus associated with elevated fetal plasma IL-6 level may reflect the biologic needs of the premature fetus to escape from the hostile intrauterine environment.     

The utility of immunohistochemistry and in situ hybridization in placental pathology

It has long been recognized that routine histologic examination of the placenta has limitations, especially with regard to the diagnosis of infectious diseases and the concomitant cytokine response that may cause severe in utero fetal damage. Immunohistochemical testing of the placenta in such situations can be very useful in terms of identifying the infectious agent as well as in demonstrating a marked increase in cytokines such as tumor necrosis factor alpha and interleukin 8, produced primarily by cells native to the villi and fetal membranes. One hundred placentas (20 normal childbirths, 20 with severe neonatal morbidity of known cause, 25 idiopathic stillbirths where autopsy material was available, 35 with severe idiopathic neonatal morbidity) were examined for a wide variety of infectious diseases and cytokine production. An infectious agent was evident in 19 (76%) of 25 placentas from stillbirths and 28 (80%) of 35 placentas associated with idiopathic severe neonatal morbidity. No infectious agent was noted in the placentas from normal childbirths or cases of known neonatal morbidity. The most common infectious agent was coxsackie virus (51% of infections) followed by bacterial infections (24% of infections). The same infectious agent found in the placenta was found in the corresponding autopsy material from the stillbirths, with the spleen containing the greatest number of infected cells. There was a strong correlation between the number of cells demonstrating cytokine expression (tumor necrosis factor alpha and interleukin 8) and the presence of an infectious disease in the placenta and stillborn. No histologic feature was associated with an in utero infection. Immunohistochemical testing of placentas gives much insight into their structure and function, including, besides infectious disease detection, the marked diversity of function of trophoblasts, the rarity of committed B cell response, and the strong potential of contractility of villi.     

Histologic correlates of viral and bacterial infection of the placenta associated with severe morbidity and mortality in the newborn

The purpose of this study was to correlate the histologic features of the placenta with the in situ detection of viral or bacterial nucleic acids in cases of severe morbidity and mortality in the neonatal period. The criteria for the cases were either fetal or neonatal death (11 cases with autopsy material available in 8 cases) or idiopathic severe respiratory distress or central nervous system-related symptoms at birth (49 cases). Controls included 11 placentas from births with no morbidity and 6 placentas that were associated with severe neonatal morbidity of known etiology (trisomy, ruptured uterus, prolapsed cord). The 77 placental tissues were analyzed with a consensus bacterial probe and for a wide variety of viral infections. An infectious cause was found in 46/60 (76%) of cases; these were distributed as follows: enterovirus, 23 cases (22 were coxsackie virus); bacterial (consensus probe), 15 cases; cytomegalovirus (CMV), 4 cases; herpes simplex virus (HSV), 2 cases; parvovirus, 2 cases. The infectious agents localized primarily to Hofbauer cells and trophoblasts. In each of the 8 cases for which autopsy material was available, the same infectious agent that was detected in the placenta was also detected in the autopsy material (spleen, heart, central nervous system, or lungs). No infectious agent was detected in any of the 17 controls. Viral inclusions (only evident for DNA viruses) and stem vessel vasculitis were the 2 histologic findings that were associated with infectious disease in the placenta (P = 0.025). These data show that infection of the villi is highly associated with neonatal morbidity and mortality and that the histologic findings are, in most cases, nonspecific for infection.     

Pathomorphology of organs of late spontaneously miscarried fetuses in ascending infection of placenta

Organs and placentas in 262 late spontaneous miscarriages caused by ascending bacterial infection of the fetal balloon were studied. The most important were the data on the stages of intrauterine pneumonia development and its link with the stages of infection in the fetal tissues and periods of pregnancy. The information is provided on the direct causes of fetal death related to structural-functional insufficiency of fetal membranes, placenta and umbilical cord.     

Experimental Feline Herpesvirus Infection in the Pregnant Cat

Intravenous inoculation of pregnant cats with feline herpesvirus produced minimal illness but resulted in abortion, intrauterine fetal death and congenital fetal infection. Placental lesions included multiple infarcts in the placental labyrinth, thrombosis of maternal vessels in the endometrium and placenta, and multifocal necrosis of the giant-cell trophoblast and endometrial epithelium in the junctional zone of the placenta associated with eosinophilic intranuclear inclusion bodies. The virus was isolated from all the placentas and uteri but from none of the fetuses aborted 6-9 days after maternal intravenous inoculation. Viral antigen was demonstrated in the uterine vessels and in the junctional zone of the placenta at this time. On postinoculation day 26, viral antigen was demonstrated in the chorioallantoic membrane on the fetal side of the placenta and in the liver of a congenitally infected fetus. Although all 4 pregnant cats inoculated intranasally with feline herpesvirus aborted, neither virus, viral antigen nor significant lesions were detected in the uteri, placentas or fetuses. Abortion after intranasal inoculation was interpreted as a nonspecific reaction secondary to the severe, debilitating upper respiratory disease that occurred.     

Structural and metabolic mechanisms of placental adaptation

Ninety-two placentas from patients with late toxaemia of pregnancy were studied by means of histologic, stereologic and enzyme histochemical methods. 32 placentas were from live births and 60 from stillbirths. In the stillbirth series, 31 placentas were from cases of fetal antepartum deaths and 29 from cases of fetal intrapartum deaths. The increase of the microcirculation volume in placental villi and the increase of oxidative enzyme activity in the syncytiotrophoblast, stroma and villi vesel wall are considered as structural and metabolic mechanisms of placenta adaptation. The role of structural and metabolic placenta insufficiency in the pathogenesis of the intrauterine fetal death is discussed.     

Placental Cellular Immune Response in Women Infected with Human Parvovirus B19 during Pregnancy

Human parvovirus B19 can cause congenital infection with variable morbidity and mortality in the fetus and neonate. Although much information exists on the B19-specific antibody response in pregnant women, little information is available describing the cell-mediated immune (CMI) response at the maternal-fetal interface. The focus of this study was to characterize the CMI response within placentas from women who seroconverted to B19 during their pregnancies and compare it to controls. Immunohistochemical techniques were used to identify the various immune cells and the inflammatory cytokine present within placental tissue sections. Group 1 consisted of placentas from 25 women whose pregnancies were complicated by B19 infection; 6 women with good outcome (near-term or term delivery), and 19 with poor outcome (spontaneous abortion, nonimmune hydrops fetalis, or fetal death). Group 2 consisted of placentas from 20 women whose pregnancies were complicated with nonimmune hydrops fetalis of known, noninfectious etiology. Group 3 consisted of placentas from eight women whose pregnancies ended in either term delivery or elective abortion. The results of the study revealed a statistically significant increase in the number of CD3-positive T cells present within placentas from group 1 compared to group 2 or 3 (13.3 versus 2 and 1, respectively) (P < 0.001). In addition, the inflammatory cytokine interleukin 2 was detected in every placenta within group 1 but was absent from all placentas evaluated from groups 2 and 3. Together, these findings demonstrate evidence for an inflammation-mediated cellular immune response within placentas from women whose pregnancies are complicated with B19 infection.     

Placental cellular immune response in women infected with human parvovirus B19 during pregnancy

Human parvovirus B19 can cause congenital infection with variable morbidity and mortality in the fetus and neonate. Although much information exists on the B19-specific antibody response in pregnant women, little information is available describing the cell-mediated immune (CMI) response at the maternal-fetal interface. The focus of this study was to characterize the CMI response within placentas from women who seroconverted to B19 during their pregnancies and compare it to controls. Immunohistochemical techniques were used to identify the various immune cells and the inflammatory cytokine present within placental tissue sections. Group 1 consisted of placentas from 25 women whose pregnancies were complicated by B19 infection; 6 women with good outcome (near-term or term delivery), and 19 with poor outcome (spontaneous abortion, nonimmune hydrops fetalis, or fetal death). Group 2 consisted of placentas from 20 women whose pregnancies were complicated with nonimmune hydrops fetalis of known, noninfectious etiology. Group 3 consisted of placentas from eight women whose pregnancies ended in either term delivery or elective abortion. The results of the study revealed a statistically significant increase in the number of CD3-positive T cells present within placentas from group 1 compared to group 2 or 3 (13.3 versus 2 and 1, respectively) (P < 0.001). In addition, the inflammatory cytokine interleukin 2 was detected in every placenta within group 1 but was absent from all placentas evaluated from groups 2 and 3. Together, these findings demonstrate evidence for an inflammation-mediated cellular immune response within placentas from women whose pregnancies are complicated with B19 infection.     

Fetal and maternal vascular lesions

Many commonly diagnosed disorders of the placenta relate to maternal and fetal blood flow and are thus common in the placentas of infants with adverse perinatal outcomes. Severe uteroplacental vascular disease may lead to extensive placental infarction and villous changes of reduced uteroplacental blood flow, a morphologic feature commonly associated with intrauterine growth restriction and fetal demise. Lesser degrees of villous change are seen in many infants with premature delivery, term, and multiple births resulting in admission to the neonatal intensive care units. Fetal vascular lesions including chorangiosis and fetal thrombotic vasculopathy are two processes that appear to be associated with increased risk of poor outcome.     

Intrauterine latent herpes simplex virus infection: II. Latent neonatal infection

Herpes simplex virus (HSV, probably type 2) antigen has been detected in endometria and abortion tissue (companion paper) and in placentae, umbilical cords, and fetal and neonatal organs by avidin-biotin complex immunohistochemical studies. HSV cytologic abnormalities were not detected in any of the 12 normal and 64 abnormal cases analyzed, nor was HSV detected by culture or electron microscopy in selected cases. Antigen was present in single epithelial and, rarely, mesenchymal cells of various organs. Clinically unexplained fetal or neonatal problems associated with HSV antigen positivity included intrauterine death, fetal growth retardation, cystic brain degeneration, hydrops, interstitial pneumonitis, necrotizing enterocolitis, hepatitis, encephalitis, myocarditis, and renal failure. Maternal floor infarct of placenta and calcifying funisitis are the manifestations of intrauterine HSV infection in most cases. Maternal history of HSV infection was uncommon. It is concluded that intrauterine HSV infection may persist in the fetus and neonate in a latent fashion without cytologic abnormalities or detectable virus. This latent infection may be associated with intrauterine and neonatal death, organ damage, and neonatal disease.     

Detection of cytomegalovirus, parvovirus B19 and herpes simplex viruses in cases of intrauterine fetal death: association with pathological findings

There are previous indications that transplacental transmission of cytomegalovirus (CMV), parvovirus B19 (PB19) and herpes simplex virus types 1 and 2 (HSV-1/2) cause fetal infections, which may lead to fetal death. In a prospective case-control study we examined the incidence of these viruses in intrauterine fetal death and their association with fetal and placenta pathological findings. Molecular assays were performed on placenta tissue extracts of 62 fetal deaths and 35 controls for the detection of CMV, PB19 and HSV-1/2 genomes. Formalin-fixed, paraffin-embedded liver, spleen and placenta tissues of fetal death cases were evaluated histologically. Thirty-four percent of placental specimens taken from intrauterine fetal deaths were positive for any of the three viruses (16%, 13%, and 5% positive for CMV, PB19, and HSV-1/2, respectively), whereas only 6% of those taken from full term newborns were positive (P = 0.0017). No dual infection was observed. This difference was also observed when fetal deaths with a gestational age <20 weeks or a gestational age >20 weeks were compared with the controls (P = 0.025 and P = 0.0012, respectively). Intrauterine death and the control groups differed in the detection rate of CMV DNA (16% and 3%, respectively; P = 0.047), which was more pronounced in a gestational age >20 weeks (P = 0.03). Examination of the pathological findings among the PCR-positive and PCR-negative fetal deaths revealed that hydrops fetalis and chronic villitis were more common among the former group (P = 0.0003 and P = 0.0005, respectively). In conclusion, an association was detected between viral infection and fetal death, which was more pronounced in the advanced gestational age. Fetal hydrops and chronic villitis were evidently associated with viral DNA detection in cases of intrauterine death.     

Inbred guinea pig model of intrauterine infection with cytomegalovirus.

Outbred guinea pigs have previously been utilized in an experimental model for the study of congenital infection with cytomegalovirus (CMV). Development of an inbred model of intrauterine CMV infection would allow analysis of the cells involved in CMV immunity, studies of transplacental CMV transfer, and investigation of the cellular immune factors that participate in intrauterine CMV infections. This study was therefore designed to assess the inbred guinea pig as a model for the study of congenital CMV infection. Intrauterine fetal and placental infection with CMV was demonstrated in inbred Strain 2 guinea pigs, and the maternal factors influencing transplacental transmission of CMV were evaluated. Infectious virus was recovered from placentas and offspring of mothers that experienced primary CMV infection during pregnancy, but not from placentas and offspring of mothers that were inoculated with CMV prior to pregnancy. However, histologic lesions consisting of focal necrosis and inflammation were seen in tissues of offspring from both groups of mothers. Inoculation of seronegative pregnant Strain 2 animals with low doses of virus (2.5 to 3.5 log10 TCID50) resulted in both placental and fetal CMV infection without significant maternal death. Infection of placentas and offspring occurred in utero regardless of the stage of pregnancy. In addition, infectious virus was detectable in fetal tissues at the time of maternal viremia but also later during the course of maternal infection, ie, 4 weeks after inoculation. These findings indicate that the inbred guinea pig model can be used to investigate the pathogenesis of intrauterine CMV infections.     

孕妇HCMV感染及妊娠结局分析

目的了解孕妇感染HCMV后对胚胎、胎儿及妊娠结局的影响.方法采用ELISA方法对4148例长沙地区孕妇进行TORCH-IgM检测.结果在对4148例长沙地区孕妇进行TORCH-IgM检测中,发现有62例孕妇为HCMV-IgM阳性,阳性率为1.5%.在随访的58例孕妇中,妊娠结局为自然流产者达31%(18/58);为死胎及胎儿畸形者达19%(11/58),显著高于其他异常妊娠结局者(P＜0.001).结论HCMV宫内感染是导致胚胎和胎儿自然流产的主要原因之一,同时也是导致胎儿宫内死亡、畸形发生的主要原因.因此,提高孕妇免疫能力,加强孕期健康教育,避免和减少易感因素的接触,是降低胎儿宫内感染的主要措施;另外,大力推广孕前优生检测也是防止胎儿宫内感染发生的重要手段.     

Fetal thrombotic vasculopathy in the placenta: cerebral thrombi and infarcts, coagulopathies, and cerebral palsy.

Thrombi in the fetal circulation of the placenta cause a pattern of clustered fibrotic villi called fetal thrombotic vasculopathy (FTV), which has been associated with serious injuries to neonates, especially brain injuries. Correlation of FTV with visceral thrombi in autopsy specimens might lead to a more accurate estimate of the prevalence of somatic thrombi as a significant and underrecognized cause of prenatal injury or perinatal death, and show the potential validity of placental FTV as an indicator of thrombotic lesions in the fetus and newborns who survive. Clinicopathologic correlation was used to perform a 3-year retrospective autopsy review. We identified 16 cases (19%) among 84 perinatal autopsy specimens in which placental FTV was associated with stillbirth, intrapartum, or neonatal death. Two liveborn neonates survived 2.5 hours, and one for 24 hours; there was one intrapartum death, and the rest were stillborn. Clinical evidence of severe central nervous system (CNS) injury to two of the liveborn infants was evident at birth. Twelve stillborns died from 12 to 48 hours before delivery. Placental FTV had features of organization that clearly antedated the fetal death. Autopsy findings confirmed somatic thrombi in six cases (37.5%) of the 16 with FTV, including cerebral thrombi or infarcts (three cases), renal thromboemboli (three cases), and pulmonary thromboemboli (two cases). One mother had history of deep vein thrombosis, and four of eight tested had abnormal coagulation test results. Placental FTV indicates a significant probability of thrombi in the fetus and represents an important, possibly underrecognized cause of perinatal mortality and neonatal injury. Parental coagulopathy as a significant factor in prenatal injury and death deserves more comprehensive study. The placenta remains an undervalued and underutilized surgical specimen in the evaluation of perinatal injury, especially cerebral palsy.     

Villitis of unknown etiology: noninfectious chronic villitis in the placenta

Villitis of unknown etiology (VUE) is an important pattern of placental injury occurring predominantly in term placentas. Although overlapping with infectious villitis, its clinical and histologic characteristics are distinct. It is a common lesion, affecting 5% to 15% of all placentas. When low-grade lesions affecting less than 10 villi per focus are excluded, VUE is an important cause of intrauterine growth restriction and recurrent reproductive loss. Involvement of large fetal vessels in the placenta (obliterative fetal vasculopathy) in cases of VUE is a strong risk factor for neonatal encephalopathy and cerebral palsy. Although the etiology of the eliciting antigen is unknown, many other characteristics of the immune response have been clarified. VUE is caused by maternal T lymphocytes, predominantly CD8-positive, that inappropriately gain access to the villous stroma. Fetal antigen-presenting cells (Hofbauer cells) expand and are induced to express class II major histocompatibility complex molecules. Maternal monocyte-macrophages in the perivillous space likely amplify the immune response. Although much speculation exists that VUE represents a host-versus-graft reaction analogous to transplant rejection, other eliciting antigens have not been excluded. Irrespective of target antigen or antigens, the pathophysiologic implications of having activated maternal lymphocytes within vascularized fetal tissues are not trivial.     

Comparative genomic hybridization: a new tool for reproductive pathology

OBJECTIVE: To demonstrate the effectiveness of comparative genomic hybridization (CGH) for analysis of reproductive pathology specimens in clinical cytogenetics laboratories. DESIGN: A total of 856 CGH analyses were performed on various placental and fetal tissues derived from 368 specimens of spontaneous abortions and on placentas from 219 pregnancies with live-born infants. The live-born infants were clinically evaluated as normally developed, with either a normal birth weight or with intrauterine growth restriction; some live-born infants had an abnormal prenatal triple screen with normal cytogenetic results on amniotic fluid cell cultures. RESULTS: Comparative genomic hybridization analysis was successfully performed on 856 samples from spontaneously aborted specimens and term placentas. Failure of analysis occurred in 1.6% of samples and was due to an insufficient amount of tissue for DNA extraction. Comparative genomic hybridization identified aneuploidy in 53% of spontaneous abortion samples and 3.1% of term placentas. CONCLUSIONS: Comparative genomic hybridization analysis is a useful clinical tool for detection of aneuploidy in placental and fetal tissues. It provides a genome-wide screen while eliminating tissue culture failures, culture artifacts, and maternal cell contamination. We present practical guidelines for interpreting CGH profiles derived from human reproductive specimens.     

Specialised pediatric pathology service

Leningrad Regional Children's Bureau of Pathology was established in May 1992. The program of this bureau consisted of: revealing causes of early and late abortions; assessment of ultrasound diagnosis of congenital deficiencies of fetus development and clinical assessment of chronic placental insufficiency; pathogenetic explanation of intrauterine fetuses death; prognosis of neonatal pathology; systemic analysis of dynamics of perinatal, natal and infant mortality; organisation of independant expertise of medical causes of reproductive losses. The following principles in the work of the bureau were established: 1) mass investigation of placentas of newborns; 2) use of urgent pathomorphological diagnosis which allows to present information about placentas not later than 24 hrs after the delivery; 3) complex investigation of placentas with the use of various methods; 4) systemic informational analysis of placental pathology; 5) constant updating of physicians knowledge in the field of practical placentology. Results of mass placentas investigation show a principal pathogenetic role of ascending infection in perinatal mortality in opportunistic pathogenic microflora with the development of inflammatory responses in the system mother-placenta-fetus.     

Genital mycoplasma infection. Intrauterine infection: pathologic study of the fetus and placenta.

Mycoplasma infection was present in the fetuses from three spontaneous abortions and in one second-trimester newborn. Gross examination revealed in most cases a severely infected placenta and membranes, with a fetus of normal appearance. The fetal infection presumably followed placental involvement and appeared to have been acquired shortly prior to delivery. Genital mycoplasmas, Ureaplasma urealyticum or Mycoplasma hominis, were isolated from the placentas and the fetal tissues, and from the genital tracts of the mothers. Isolation of mycoplasmas from the liver indicated that bloodstream dissemination of these organisms occurred in the fetus. In the fetus, the pathologic changes were variable. Lesions were identified in the lung by scanning electron microscopy of the bronchial tree in two cases and were accompanied by interstitial pneumonia. An abnormally dilated left ventricle suggestive of cardiomyopathy was observed in one case.     

Pathogenetic characteristics of late spontaneous miscarriage in ascending infection of amnion: reaction of placenta

Results of pathomorphological examination of placenta in 262 cases of late spontaneous miscarriages produced by ascending infection of fetal liquids with opportunistic microflora are presented. Sequential involvement in the exudative inflammatory process of the fetal membranes was observed (placenta and umbilical cord) depending on the term of pregnancy and duration of placenta contact with the infected fetal liquids. Exudative funiculitis was observed not infrequently this indicating direct involvement of the fetus in the intrauterine infectious process.