Chronic Villitis Research Articles

Placental Histopathologic Findings of a Large Cohort of Patients With SARS-CoV-2 Infection During Pregnancy.

Pregnant individuals with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are at a higher risk for adverse pregnancy outcomes. Previous small cohort studies have shown increased frequency of placental lesions associated with maternal vascular malperfusion, fetal vascular malperfusion, and inflammation among patients with SARS-CoV-2, without controlling for cardiometabolic risk factors among many such patients. We aimed to evaluate whether SARS-CoV-2 infection during pregnancy is independently associated with placental abnormalities when controlling for risk factors that could affect placental histopathology. Retrospective cohort study of placentas from singleton pregnancies in Kaiser Permanente Northern California from March to December 2020. Pathologic findings were compared among those with confirmed cases of SARS-CoV-2 during pregnancy and those without. We examined the association between SARS-CoV-2 infection and categorical placental pathologies, controlling for maternal age, gestational age, prepregnancy body mass index, gestational hypertension, preeclampsia/eclampsia, preexisting diabetes, history of thrombosis, and stillbirth. A total of 2,989 singleton gestation placentas were analyzed, 416 (13%) from pregnancies with SARS-CoV-2 infection and 2,573 (86%) from those without infection. Among placentas from pregnancies with SARS-CoV-2, 54.8% had evidence of inflammation, 27.1% maternal malperfusion abnormality, 20.7% massive perivillous fibrin or chronic villitis, 17.3% villous capillary abnormality, and 15.1% fetal malperfusion. After controlling for risks factors and stratifying interval time between SARS-CoV-2 infection and delivery, no association was found between placental abnormalities and SARS-CoV-2 infection during pregnancy. SARS-CoV-2 infection was not associated with an increased risk of placentally mediated adverse outcomes during pregnancy, compared with placentas sent for other indications, in this large diverse cohort.

The Multifaceted Clinical Characteristics of Congenital Cytomegalovirus Infection: From Pregnancy to Long-Term Outcomes.

The aim of this study was to capture multifaceted clinical characteristics of congenital cytomegalovirus (CMV) infection from diagnosis to treatment using a multidisciplinary approach including obstetrics, pediatrics, pathology, and otorhinolaryngology-head and neck surgery. This is a retrospective study including 30 consecutive cases of congenital CMV infection that were diagnosed at a single tertiary hospital located in Seoul, Korea from January 2009 to December 2020. Congenital CMV infection was defined as a positive result by polymerase chain reaction from urine, saliva or cerebrospinal fluid or positive CMV IgM from neonatal blood sampled within 3 weeks after birth. All cases were analyzed with respect to whole clinical characteristics from diagnosis to treatment of congenital CMV by a multidisciplinary approach including prenatal sonographic findings, maternal immune status regarding CMV infection, detailed placental pathology, neonatal clinical manifestation, auditory brainstem response test, and antiviral treatment (ganciclovir or valganciclovir). Long-term outcomes including developmental delay and hearing loss were also investigated. The total number of births during the study period in our institution was 19,385, with the prevalence of congenital infection estimated to be 0.15%. Among 30 cases of congenital CMV, the median gestational age at delivery was 32.2 weeks [range, 22.6-40.0] and 66.7% of these infants were delivered preterm at less than 37 weeks. Suspected fetal growth restriction was the most common prenatal ultrasound finding (50%) followed by ventriculomegaly (17.9%) and abnormal placenta (17.9%), defined as thick placenta with calcification. No abnormal findings on ultrasound examination were observed in one-third of births. Maternal CMV serology tests were conducted in only 8 cases, and one case each of positive and equivocal IgM were found. The most common placental pathologic findings were chronic villitis (66.7%) and calcification (63.0%), whereas viral inclusions were identified in only 22.2%. The most common neonatal manifestations were jaundice (58.6%) followed by elevation of aspartate aminotransferase (55.2%) and thrombocytopenia (51.7%). After excluding cases for which long-term outcomes were unavailable due to death (n = 4) or subsequent follow up loss (n = 3), developmental delay was confirmed in 43.5% of infants (10/23), and hearing loss was confirmed in 42.9% (9/21) during the follow-up period. In our cohort, 56.7% (17/30) of neonates were treated for congenital CMV with ganciclovir or valganciclovir. Our data show that prenatal findings including maternal serologic tests and ultrasound have limited ability to detect congenital CMV in Korea. Given that CMV is associated with high rates of developmental delay and hearing loss in infants, there is an urgent need to develop specific strategies for the definite diagnosis of congenital CMV infection during the perinatal period by a multidisciplinary approach to decrease the risks of neurologic impairment and hearing loss through early antiviral treatment.

Toxoplasma gondii-associated Placentitis in the absence of maternal seroconversion

Severe granulomatous chronic villitis with focal remnants of Toxoplasma was confirmed by immunohistochemistry and DNA-based methods in the placenta from a child that died four days after birth. The immunocompetent mother was seronegative for Toxoplasma at delivery and 10 months later. Placental infection may happen without maternal systemic infection.

Prenatal and Postnatal Zika Intrauterine Infection: Diagnostic Imaging Techniques and Placental Pathology

Introduction: Zika virus (ZIKV) is an arbovirus (arthropod-borne virus) in the genus Flavivirus and Flaviviridae family. In November 2015, several cases of microcephaly in Northeastern of Brazil suggested ZIKV involvement. Case Report: A 33-year-old primigravida developed fever and cutaneous rash at 7th week of gestation (WGA). The ultrasound and MRI examination showed head circumference < 5th centile and enlargement of lateral ventricles. The infant was delivered at 39th WGA with microcephaly. Microscopy of the placenta showed chronic villitis and intervillitis, nodular stromal fibrosis in the stem villi, and vascular thickening. Postnatal CT showed collapsed cranium due to growth impairment of the suprathalamic brain, multiple cerebral calcifications, parenchymal atrophy, and ventricular dilatation. Now, at 6 years old, the child suffers from severe neurologic symptoms, including seizures. Conclusion: This case gathers images of prenatal and postnatal period, and placental histopathology. The long-term follow-up highlights the dramatic neurological sequelae induced by ZIKV.

Chronic villitis of unknown aetiology: an Australian institution's 5-year experience

Villitis of unknown aetiology (VUE) is a chronic inflammatory condition of the placenta that is associated with increased morbidity and mortality in perinatal medicine. The cause remains elusive and recent studies have explored immune-mediated, infectious and environmental triggers in the pathogenesis of VUE. The objective of this study was to identify the characteristics of VUE diagnoses at Mater Mothers' Hospital over a 5-year period, including any association with seasons, maternal age and histological patterns of the disorder. We retrospectively reviewed reports for placentas sent to Mater Pathology, Brisbane, over 5 years (December 2015 to November 2020). Case level data were retrieved including maternal age, the month of delivery, gestational age, parity, VUE status, recurrence, histopathological subtype and grade. Univariable and multivariable logistic regression was used to estimate the unadjusted and adjusted association between VUE and season, maternal age and trimester at delivery. While more placentas were examined during summer than winter (p=0.005), there was no evidence of seasonal variation in the incidence of VUE over the 5 years (p=0.17). Both univariable and multivariable logistic regression analyses showed that VUE increased with maternal age (p<0.001) and gestational age (9.8% of examined placentas in the third trimester compared to 2.1% in first and second trimesters, p<0.001). Seven of 714 women with VUE (0.98%) had one or more recurrences of the condition within the study period. Of these, VUE was of lower grade in two of the three women who were prescribed aspirin in the subsequent pregnancy. Furthermore, basal VUE without basal myometrial fibres (6.6%), was over-represented among clinically morbidly adherent placentas (MAP) reported in this cohort. Our study does not show evidence of a seasonal variation in VUE incidence. The immune-mediated pathogenesis of VUE is favoured, with our data showing increased rates of the condition as maternal age increases.

COVID-19-associated pathological changes in placentae of third-trimester pregnant women

Background and aim Recently, many instances of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) [coronavirus disease 2019 (COVID-19)] placental invasion in late pregnancy have been reported, and this is still not completely clear. Controversy data are sequentially published, so more studies are needed to investigate placental pathology as it gives vital information on placental changes, mechanisms of maternal–fetal infection transmission, and viral effects on the placenta as inflammatory or vascular changes. We aimed to find out the placental pathological changes in term placentae and to detect SARS-CoV-2 RNA in specimens fixed in formalin and embedded in paraffin. Patients and methods A total of 30 placentae were obtained from COVID-19-infected pregnant women. They were examined for pathological changes by histopathology; immunohistochemistry for CD3, CD20, CD15, CD68, angiotensin-converting enzyme 2, cytokeratin, and PDL-1; and reverse transcription-PCR to recognize viral RNA. Results According to the COVID-19 status at the delivery time, four groups were identified. Group 1 (12 patients with COVID-19 at the delivery time) showed chronic villitis and placental maternal and fetal malperfusion. Group 2 (seven cases that turned negative by PCR of the nasopharyngeal swab prior to delivery by 5–8 days) showed maternal malperfusion but no villitis. Both groups were SARS-CoV-2 RNA positive by PCR of the nasopharyngeal swab. Group 3 (five cases that turned negative 1 day before delivery) showed maternal–fetal malperfusion and mild chronic subchorionitis and deciduitis. Only three had SARS-CoV RNA. Group 4 (six cases with a persistent negative swab for 20 days before delivery) showed focal villitis (much less than other groups) and maternal malperfusion. Only two had SARS-CoV-2 RNA. Immunophenotyping of cases in the four groups detected mixed inflammatory infiltrate with variable diffuse angiotensin-converting enzyme 2 immunostaining of villus and extravillous trophoblasts. Cytokeratin staining detected thinning and discontinuity of syncytiotrophoblast and strong PD-L1 expression was seen in villitis areas. Conclusion SARS-CoV-2-positive women exhibited a diverse range of results; thus, pregnant women should not be considered a homogeneous group as outcomes are dependent on a multitude of interdependent circumstances.

Autopsies and placental examinations of perinatal fetal deaths: a clinicopathological analysis of 105 cases

Objective: To summarize the clinicopathological factors related to perinatal fetal death and to evaluate importance of fetal autopsy and placental pathology. Methods: The clinicopathological data of 105 perinatal fetal deaths in Beijing Haidian Maternal and Child Health Hospital from November 2012 to December 2020 were retrospectively analyzed. Relevant literature was also reviewed. Results: The maternal age of the deceased fetuses ranged from 22 to 43 years with the average (31.35±4.04 years), and the gestational weeks were 28-40+6 weeks. Among them, 101 were singleton cases and 4 twin cases. 103 fetuses died in uterus and 2 died during delivery. Relevant factors analysis of the 105 perinatal fetal deaths showed that 86 cases (81.9%, 86/105) were related to umbilical cord/placental abnormality, 10 cases (9.5%, 10/105) uterine infection, 6 cases (5.7%, 6/105) fetal factors, 1 case was fetal maternal blood transfusion syndrome, 1 case twin blood transfusion syndrome, and 1 case died of complete uterine rupture. Among the 86 cases related to umbilical cord/placental abnormality, the diagnosis was most often based on the gross examination of placenta. The most common cause of death was umbilical cord torsion with thin root, followed by placental abruption, tight umbilical cord winding, vascular rupture and umbilical cord true knot. The morphology of placenta revealed mainly functional changes. Among the 10 cases related to intrauterine infections, the placenta generally showed lobular placental edema. The morphological characteristics of ascending infection were mainly acute chorioamnionitis, and the morphological characteristics of blood-borne infection were mainly acute or chronic villitis, as well as villous interstitial inflammation. Identification of viral inclusions suggested viral etiology, while the final diagnosis was relied on laboratory testing. Among the 6 cases related to fetal abnormality, the diagnostic value of placenta was limited and the diagnosis could be made with fetal autopsy. Conclusion: The causes of perinatal fetal death are complex, diverse, and often the synergistic result of multiple factors. Fetal autopsy and placental pathology are the key technical means to identify the cause of death and deserve more attention and utilization.

Diffuse and Localized SARS-CoV-2 Placentitis: Prevalence and Pathogenesis of an Uncommon Complication of COVID-19 Infection During Pregnancy.

Coronavirus disease 2019 (COVID-19) infection in pregnancy has been associated with preterm delivery and preeclampsia. A less frequent and underrecognized complication is extensive placental infection which is associated with high rates of perinatal morbidity and mortality. The frequency, early pathogenesis, and range of lesions associated with this infection are poorly understood. We conducted a population-based study of placental pathology from all mothers with COVID-19 (n=271) over an 18-month period delivering within our health system. The overall prevalence of diffuse severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) placentitis, as defined by typical histology and immunohistochemical (IHC) staining for SARS-CoV-2 spike protein, was 14.8/1000, but increased to 59/1000 in preterm births. We also identified 3 cases with isolated small foci of localized SARS-CoV-2 placentitis, characterized by focal perivillous fibrin and intervillositis, which illustrate the early pathogenesis and suggest that infection may be contained in some cases. Two other placental lesions were more common in mothers with COVID-19, high-grade maternal vascular malperfusion in preterm deliveries and high-grade chronic villitis at term (5/5 cases tested of the latter were negative by IHC for SARS-CoV-2). Additional investigation of diffuse and localized SARS-CoV-2 placentitis by IHC showed loss of BCL-2, C4d staining in surrounding villi, and an early neutrophil-predominant intervillous infiltrate that later became dominated by monocyte-macrophages. We propose a model of focal infection of syncytiotrophoblast by virally infected maternal leukocytes leading to loss of BCL-2 and apoptosis. Infection is then either contained by surrounding fibrinoid (localized) or initiates waves of aponecrosis and immune activation that spread throughout the villous parenchyma (diffuse).

Recurrence risk of villitis of unknown etiology: Analysis of a large retrospective cohort study, systematic review and meta-analysis.

Recurrence risk of villitis of unknown etiology (VUE) remains uncertain because of few studies and their methodologic limitations. We calculated recurrence risk in a large population of deliveries after minimizing important biases and compared it to others via systematic review and meta-analysis. Over 11 years of placenta pathology reports on singleton deliveries were retrieved and searched for 'villitis' or 'VUE'. Cases of acute villitis and chronic villitis from infections were eliminated via pathologist review. Reports were merged to data containing gestational age, parity and gravida. Recurrence risk of VUE per patient, per parity and per gravida was determined among patients with ≥2 placentas examined for deliveries ≥20 weeks gestation. Results were compared to those from articles and their references identified by a MEDLINE® search. Recurrence risks among methodologically similar studies were pooled using a random effects model. Among 29124 placenta pathology reports from 27087 patients, there were 2423 cases of VUE among 2382 patients, of which 153 had ≥2 placentas examined. There were 41 recurrent cases of VUE for a recurrence risk of 27% per patient, 22% per parity, and 19% per gravida. We identified 64 articles, of which 4 were retained. One examined all placentas from all births over a ∼3-year period, finding a recurrence risk of 27%. The remaining 3 studies, along with our own, used indications for placental examination and had a pooled recurrence risk of 30% (95% Confidence Interval: 0.21-0.41). In our study, which is the largest, most comprehensive, and methodologically robust to date, VUE recurrence risk was ∼30%.

Placental Tissue Destruction and Insufficiency From COVID-19 Causes Stillbirth and Neonatal Death From Hypoxic-Ischemic Injury.

Perinatal death is an increasingly important problem as the coronavirus disease 2019 (COVID-19) pandemic continues, but the mechanism of death has been unclear. To evaluate the role of the placenta in causing stillbirth and neonatal death following maternal infection with COVID-19 and confirmed placental positivity for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Case-based retrospective clinicopathologic analysis by a multinational group of 44 perinatal specialists from 12 countries of placental and autopsy pathology findings from 64 stillborns and 4 neonatal deaths having placentas testing positive for SARS-CoV-2 following delivery to mothers with COVID-19. Of the 3 findings constituting SARS-CoV-2 placentitis, all 68 placentas had increased fibrin deposition and villous trophoblast necrosis and 66 had chronic histiocytic intervillositis. Sixty-three placentas had massive perivillous fibrin deposition. Severe destructive placental disease from SARS-CoV-2 placentitis averaged 77.7% tissue involvement. Other findings included multiple intervillous thrombi (37%; 25 of 68) and chronic villitis (32%; 22 of 68). The majority (19; 63%) of the 30 autopsies revealed no significant fetal abnormalities except for intrauterine hypoxia and asphyxia. Among all 68 cases, SARS-CoV-2 was detected from a body specimen in 16 of 28 cases tested, most frequently from nasopharyngeal swabs. Four autopsied stillborns had SARS-CoV-2 identified in internal organs. The pathology abnormalities composing SARS-CoV-2 placentitis cause widespread and severe placental destruction resulting in placental malperfusion and insufficiency. In these cases, intrauterine and perinatal death likely results directly from placental insufficiency and fetal hypoxic-ischemic injury. There was no evidence that SARS-CoV-2 involvement of the fetus had a role in causing these deaths.

The Potential Benefit of Hydroxychloroquine in Chronic Placental Inflammation of Unknown Etiology Associated with Adverse Pregnancy Outcomes.

The placenta is the site of connection between maternal and fetal circulation, and the liaison is established early in pregnancy. A large variety of pregnancy complications such as preterm birth, fetal growth restriction, or pregnancy loss have placental expression and can be accompanied in some cases of acute or chronic identifiable placental inflamatory lesions. Chronic placental inflammatory (CPI) lesions include chronic villitis of unknow etiology (CVUE), chronic intervillositis of unknown etiology, CIUE (also described as chronic histiocytic intervillositis, CHI), and chronic deciduits. Hydroxychloroquine (HCQ) has been prescribed with good results during pregnancy to prevent adverse perinatal outcomes in maternal autoimmune conditions. Its success has paved the way to its use in CPI as CIUE/CHI; however, to date, there are no prospective, informatively designed, controlled studies on its value in these setting. This review aims to explore the potential role of HCQ in CPI of unknown etiology. Ideally, properly designed, probably multicentric studies should be undertaken to fully understand HCQ’s role for prevention of adverse pregnancy outcomes after a chronic placental inflammation.

Incidental Finding of Extreme Elevation of Serum Alkaline Phosphatase in Pregnancy

Increased levels of alkaline phosphatase (ALP) should alert us to changes in the liver, kidney, bone and malignancy. However, there is a physiological increase in pregnancy up to twice the upper limit. There has been a paucity of cases reporting extreme elevations of ALP in pregnancy. This is a case of an incidental pregnancy finding of a 24-fold increase in ALP in the third trimester (2877 U/L). The patient was kept under surveillance and ALP levels were monitored during the postpartum period.Literature suggests a correlation between ALP elevation and several perinatal complications, proposing it could represent an important tool in monitoring high-risk pregnancies and underlying placental damage. We report a case with no perinatal complications and normal labor at term, with a placenta showing lesions of chronic villitis. We should not rely exclusively on an isolated, marked rise in ALP to dictate the approach in the absence of other fetomaternal considerations.

Chronic villitis: Refining the risk ratio of recurrence using a large placental pathology sample

IntroductionChronic villitis is an inflammatory lesion that affects 5–15% of placentas and is associated with adverse pregnancy outcomes. Chronic villitis may also recur; however, studies estimating recurrence are based on small samples and estimates of recurrence range from 10 to 56%. MethodsWe utilized data from placentas submitted to pathology at a Chicago hospital between January 2009 and March 2018. During the study period, 883 patients had two placentas submitted to pathology. We estimated the risk of recurrent chronic villitis, adjusted for maternal and pregnancy characteristics. We also evaluated whether prevalence of small for gestational age infant differed for those with recurrent chronic villitis and we investigated whether placental pathology worsened in the second study pregnancy among those with recurrent chronic villitis. ResultsThe overall prevalence of recurrent chronic villitis in the study sample was 11.5%. Among those with chronic villitis in the first pregnancy, 54% developed chronic villitis in the second pregnancy, corresponding to an adjusted risk ratio of 2.36 (95% confidence interval: 1.92, 2.91). Recurrent chronic villitis was not associated with increased prevalence of small for gestational infant as compared with non-recurrent villitis. Among those with recurrent chronic villitis, high-grade chronic inflammation and fetal vascular malperfusion were more common in the second pregnancy as compared with the first. DiscussionOur results suggest that those with chronic villitis in the first pregnancy are over twice as likely to develop chronic villitis in the second pregnancy and that chronic inflammation and fetal vascular malperfusion may worsen among those with recurrent chronic villitis.

Expression of Immune Checkpoint Receptors in Placentae With Infectious and Non-Infectious Chronic Villitis.

Pregnancy is an immunological paradox whereby maternal immunity accepts a genetically unique fetus (or fetuses), while maintaining protective innate and adaptive responses to infectious pathogens. This close contact between the genetically diverse mother and fetus requires numerous mechanisms of immune tolerance initiated by trophoblast cell signals. However, in a placental condition known as villitis of unknown etiology (VUE), there appears to be a breakdown in this tolerance allowing maternal cytotoxic T-cells to traffic into the placenta to destroy fetal villi. VUE is associated with several gestational complications and an increased risk of recurrence in a subsequent pregnancy, making it a significant obstetrical diagnosis. The cause of VUE remains unclear, but dysfunctional signaling through immune checkpoint pathways, which have a critical role in blunting immune responses, may play an important role. Therefore, using placental tissue from normal pregnancy (n=8), VUE (n=8) and cytomegalovirus (CMV) infected placentae (n=4), we aimed to identify differences in programmed cell death 1 (PD-1), programmed death ligand-1 (PD-L1), LAG3 and CTLA4 expression between these etiologies by immunohistochemistry (IHC). Results demonstrated significantly lower expression of PD-L1 on trophoblast cells from VUE placentae compared to control and CMV infection. Additionally, we observed significantly higher counts of PD-1+ (>100 cells/image) and LAG3+ (0-120 cells/image) cells infiltrating into the villi during VUE compared to infection and control. Minimal CTLA4 staining was observed in all placentae, with only a few Hofbauer cells staining positive. Together, this suggests that a loss of tolerance through immune checkpoint signaling may be an important mechanism leading to the activation and trafficking of maternal cells into fetal villi during VUE. Further mechanistic studies are warranted to understand possible allograft rejection more clearly and in developing effective strategies to prevent this condition from occurring in utero.

Platelet alloimmunization is associated with low grade chronic histiocytic intervillositis - A new link to a rare placental lesion?

IntroductionMaternal alloimmunization against human platelet antigen (HPA)-1a has been implied to mediate both reduced birth weight and chronic placental inflammation. Fetal growth restriction is associated with different types of chronic inflammation in the placenta, mainly chronic histiocytic intervillositis and chronic villitis. The aim of this prospective study was to do a systematic examination of placentas from HPA-1a alloimmunized pregnancies, with focus on the histopathological and immunohistochemical diagnosis of variants of chronic inflammation. Material and methodsIn a Polish-Norwegian study, 48 placentas were examined. The histopathology of placentas from 27 HPA-1a immunized women was compared with 21 placentas from non-immunized HPA-1a negative women (controls). In the group of alloimmunized women, ten received antenatal intravenous immunoglobulin G (IVIg). Tissue sections from formalin fixed paraffin embedded placental tissue were stained with hematoxylin and eosin and microscopically examined with focus on various types of chronic placental inflammations. ResultsChronic histiocytic intervillositis was observed in 40.7% of placentas from HPA-1a alloimmunized pregnancies, compared to none in the control group (p ​= ​0.001). Chronic villitis of unknown etiology was more frequently found in the alloimmunized group, however this difference was not statistically significant. Maternal administration of IVIg did not seem to protect against chronic inflammatory lesions. DiscussionPlacentas with detectable maternal anti-HPA-1a antibodies are associated with highly increased risk of low-grade chronic histiocytic intervillositis.

HIV, Placental Pathology, and Birth Outcomes-a Brief Overview.

The spectrum of placental pathology in human immunodeficiency virus (HIV) is vast. Features observed are not only limited to the effects of the virus itself but may include that of coinfections such as tuberculosis and syphilis. The presence of other comorbidities and changes as a result of antiretroviral therapy may further confound the histologic findings. There is a paucity of unbiased information of the effects of maternal HIV on the placenta and how these changes relate to birth outcomes. Antiretroviral therapy, now in widespread use, has altered the course of maternal HIV disease and it is unknown whether this has altered the pathophysiology of HIV on the placenta. HIV-associated placental findings that have been most well described include acute chorioamnionitis, low placental weight, and maternal vascular malperfusion, with a tendency towards lower rates of chronic villitis.

Effects of ‘rescue’ dose of antenatal corticosteroids on placental histopathology in preterm births

IntroductionAntenatal corticosteroids (ACS) are frequently used to reduce neonatal morbidity in preterm births (PTBs). A ‘rescue’ dose of ACS can be administer, if the risk of PTB remains. Some reports indicated that repeated doses of ACS might impact placental histology and possibly its function. We aimed to study whether repeated doses of ACS effect placental histopathology and pregnancy outcome. MethodsThe medical files and placental reports of all PTB, at 24-336/7 weeks, between Nov 2008–Dec 2019, were reviewed. The study population was divided into three groups; no-ACS (PTBs without ACS treatment), one-ACS (PTBs after a full or partial ACS course), and rescue-ACS (PTBs after a ‘rescue’ course of ACS). Placental lesions were classified according to “Amsterdam” criteria into maternal and fetal vascular malperfusion lesions, maternal and fetal inflammatory responses and chronic villitis. Placental lesions and pregnancy outcome were compared between the study groups. ResultsThe no-ACS group (n = 58) was characterized by increased rates of PTB<28 weeks (p = 0.003), perinatal death (p < 0.001) and composite neonatal infectious morbidity (p = 0.022), as compared to the one-ACS group (n = 331) and the rescue-ACS group (n = 53). Placental MIR lesions were more common among the rescue-ACS group, compared to the one- and no-ACS groups (p = 0.022). Other placental lesions did not differ between the groups. On multivariate logistic regression analysis, MIR lesions were independently associated with rescue-ACS treatment (aOR 3.00, 95% CI 1.10–8/17, p = 0.031). DiscussionRescue course of ACS is associated with increased rate of placental maternal inflammatory response. These findings probably result from maternal stress stimuli without an adverse impact on early neonatal outcome.

Customized birth-weight centiles and placenta-related fetal growth restriction.

The value of using customized birth-weight centiles to improve the diagnostic accuracy for fetal growth restriction (FGR), in comparison with using population-based charts, remains a matter of debate. One potential explanation for the conflicting data is that most studies used measures of perinatal mortality and morbidity as proxies for placenta-mediated FGR, many of which are not specific and may be confounded by other factors such as prematurity. The aim of this study was to compare the diagnostic accuracy of small-for-gestational age (SGA) at birth, defined according to customized vs population-based charts, for associated abnormal placental pathology. This was a secondary analysis of data from a prospective cohort study on risk factors for placenta-mediated complications and abnormal placental pathology in low-risk nulliparous women. All placentae were sent for detailed histopathological examination by two perinatal pathologists. The primary exposure was SGA, defined as birth weight < 10th centile for gestational age using either a customized (SGAcust ) or a population-based (SGApop ) birth-weight reference. The outcomes of interest were one of three types of abnormal placental pathology associated with FGR: maternal vascular malperfusion (MVM), chronic villitis and fetal vascular malperfusion (FVM). Adjusted relative risks (aRR) with 95% CIs were estimated using modified Poisson regression analysis, with adjustment for smoking, body mass index and aspirin treatment. A total of 857 nulliparous women met the study criteria. The proportions of infants identified as SGA based on the customized and population-based charts were 12.6% (108/857) and 11.4% (98/857), respectively. A diagnosis of SGA using either customized or population-based charts was associated with an increased risk of any placental pathology (aRR, 3.04 (95% CI, 2.29-4.04) and 1.60 (95% CI, 1.10-2.31), respectively) and MVM pathology (aRR, 12.33 (95% CI, 6.60-23.03) and 5.29 (95% CI, 2.87-9.76), respectively). SGAcust , but not SGApop , was also associated with an increased risk for chronic villitis (aRR, 1.85 (95% CI, 1.07-3.18)) and FVM pathology (aRR, 2.48 (95% CI, 1.25-4.93)). SGAcust had a higher detection rate for any placental pathology (30.3% vs 17.1%; P < 0.001), MVM pathology (63.2% vs 39.5%; P = 0.003) and chronic villitis (20.8% vs 8.3%; P = 0.007) than did SGApop , for a similar false-positive rate. This was mainly the result of a higher detection rate for abnormal pathology in the white and East-Asian subgroups and a lower false-positive rate for abnormal pathology in the South-Asian subgroup by SGAcust than by SGApop . In addition, pregnancies in the SGAcust group, but not those in the SGApop group, were more likely to be complicated by preterm birth and a low 5-min Apgar score than were the corresponding non-SGA group. These findings suggest that customized birth-weight centiles may be superior to population-based birth-weight centiles in detecting FGR that is due to underlying placental disease. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Chronic villitis of unknown etiology: Investigations into viral pathogenesis

IntroductionChronic villitis of unknown etiology (VUE) is a chronic inflammatory lesion of third trimester placenta, which contributes to major adverse obstetric outcomes. However, the inciting factors and mechanisms by which VUE contributes to adverse outcomes are poorly understood. This limits our ability to develop preventions or interventions. Our goals were to determine whether viruses can be detected in placental tissues with VUE and to determine whether gene expression profiles support an antiviral response. MethodsWe extracted RNA and DNA from 20 placentas with high-grade chronic villitis and 20 control placentas without inflammation. Viruses were assessed using ViroCap viral nucleic acid enrichment coupled with metagenomic sequencing. RNA sequencing was used to evaluate the inflammatory gene expression profiles in each placenta. ResultsWe detected at least 1 virus in 50% of the samples tested. We found that herpesviruses, were found more frequently in cases compared with controls (P = 0.01). Antiviral pathways, including defense response to virus, interferon gamma response, and IFN alpha/beta response, were upregulated in cases. We observed two clusters of gene expression profiles in the VUE cases, suggesting multiple inflammatory profiles are associated with VUE. DiscussionThese data support a viral etiology for some cases of VUE. Furthermore, gene expression profiles suggest the possibility of more than one cause or manifestation of VUE. Viral mechanisms should be explored as potential targets for prevention or intervention in VUE.

Clinical correlates of histopathological entities of the placenta.

General and allied health practitioners caring for pregnant women and neonates often encounter placental histopathological reports with esoteric diagnostic entities of contentious clinical significance such as chronic villitis, massive perivillous fibrin deposition, chronic histiocytic intervillositis, materno-fetal vascular malperfusion and delayed villous maturation. These lesions may recur in subsequent pregnancies. The aim of this article is to review the status quo of placental pathology and research with an emphasis on clinical management implications for some of these most often reported but less understood recurrent clinicopathological entities of the placenta. An update on the current nomenclature and classification of placental conditions is also provided. When reported adequately and interpreted correctly, placental histopathology provides useful information that may explain adverse pregnancy outcomes and guides further management of the mother, newborn or future pregnancy. Empirical treatments for immune-mediated placental conditions with prednisolone, aspirin, heparin and intravenous immunoglobulins have been reported. However, evidence-based guidelines for management of these conditions are lacking, and more research, including clinical trials, is in order.