Placental Pathologic Associations With Morbidly Adherent Placenta: Potential Insights Into Pathogenesis

Identification and stratification of placenta percreta with gynecologic oncologist management

OBJECTIVE

Gynecologic oncologist involvement in the surgical team of patients with placenta percreta has shown improved patient outcomes. Yet, stratification of cases is dependent on identification of placenta percreta by ultrasonography which has a poor detection rate. To allow patients to receive optimal team management by pre-operative stratification our objective was to identify the pre-operative characteristics of patients with previously underdiagnosed placenta percreta.

METHODS

A retrospective single institution case-control study was performed from January 2010 to December 2022 of singleton, non-anomalous pregnancies with suspicion for placenta accreta spectrum (PAS). Ultrasonography was used as the primary method of detection. Final inclusion was dependent on histology confirmation of PAS and degree of invasion. We explored the role of concurrent antenatal magnetic resonance imaging (MRI) on patients with previously unrecognized placenta percreta.

RESULTS

During the 13 year study period, 140 cases of histologically confirmed PAS were managed by our team and met inclusion criteria. A total of 72 (51.4%) cases were for placenta percreta and 27 (37.5%) of these were diagnosed pre-operatively while 45 (62.5%) were only diagnosed post-operatively. Comparison between these two groups revealed patient body mass index (BMI) >30 kg/m2 was independently associated with unrecognized placenta percreta (p=0.006). No findings by MRI were associated with mischaracterization of placenta percreta. Yet, concurrent MRI assessment of patients with BMI >30 kg/m2 (n=18), increased placenta percreta detection by 11 cases (61%).

CONCLUSION

The ability to determine pre-operatively which patients are more likely to have placenta percreta allows for gynecologic oncologists to be involved in the most complex cases in a planned manner. This study shows that women at risk for placenta accreta spectrum, who are obese (BMI >30 kg/m2), may benefit from further assessment with pre-operative MRI to facilitate appropriate staffing and team availability for cases of placenta percreta.

Methylation alterations of imprinted genes in different placental diseases

BACKGROUND

Imprinted genes play important functions in placentation and pregnancy; however, research on their roles in different placental diseases is limited. It is believed that epigenetic alterations, such as DNA methylation, of placental imprinting genes may contribute to the different pathological features of severe placental diseases, such as pre-eclampsia (PE) and placenta accreta spectrum disorders (PAS).

RESULTS

In this study, we conducted a comparative analysis of the methylation and expression of placental imprinted genes between PE and PAS using bisulfite sequencing polymerase chain reaction (PCR) and quantitative PCR, respectively. Additionally, we assessed oxidative damage of placental DNA by determining 8-hydroxy-2'-deoxyguanosine levels and fetal growth by determining insulin-like growth factor 2 (IGF2) and cortisol levels in the umbilical cord blood using enzyme-linked immunosorbent assay. Our results indicated that methylation and expression of potassium voltage-gated channel subfamily Q member 1, GNAS complex locus, mesoderm specific transcript, and IGF2 were significantly altered in both PE and PAS placentas. Additionally, our results revealed that the maternal imprinted genes were significantly over-expressed in PE and significantly under-expressed in PAS compared with a normal pregnancy. Moreover, DNA oxidative damage was elevated and positively correlated with IGF2 DNA methylation in both PE and PAS placentas, and cortisol and IGF2 levels were significantly decreased in PE and PAS.

CONCLUSIONS

This study suggested that DNA methylation and expression of imprinted genes are aberrant in both PE and PAS placentas and that PE and PAS have different methylation profiles, which may be linked to their unique pathogenesis.

Evaluation of maternal serum VEGF, TNF-alpha, IL-4, and IL-10 levels in differentiating placenta accreta spectrum from isolated placenta previa

OBJECTIVE

Our study aimed to differentiate patients with placenta accreta spectrum (PAS) from those with placenta previa (PP) using maternal serum levels of vascular endothelial growth factor (VEGF), tumor necrosis factor-alpha (TNF-alpha), interleukin-4 (IL-4), and IL-10.

METHODS

The case group consisted of 77 patients with placenta previa, and the control group consisted of 90 non-previa pregnant women. Of the pregnant women in the case group, 40 were diagnosed with PAS in addition to placenta previa and 37 had placenta previa with no invasion. The maternal serum VEGF, TNF-alpha, IL-4, and IL-10 levels were compared between the case and control groups. Then the success of these markers in differentiating between PP and PAS was evaluated.

RESULTS

We found the VEGF, TNF-alpha, and IL-4 levels to be higher and the IL-10 level to be lower in the case group compared to the control group (p < 0.001). We observed a statistically significantly lower IL-10 level in the patients with PAS than those with PP (p = 0.029). In the receiver operating characteristic analysis, the optimal cut-off of IL-10 in the detection of PAS was 0.42 ng/mL). In multivariate analysis, the risk of PAS was significant for IL-10 (odds ratio (OR) 0.45, 95 % confidence interval (CI) 0.25-0.79, p = 0.006) and previous cesarean section (OR 2.50, 95 % Cl 1.34-4.66, p = 0.004). The model's diagnostic sensitivity and specificity, including previous cesarean section, preoperative hemoglobin (Hb), TNF-alpha, and IL-10 were 75 % and 72.9 %, respectively.

CONCLUSION

The study showed that the IL-10 level was lower in patients with PAS than in those with PP. A statistical model combining risk factors including previous cesarean section, preoperative Hb, TNF-alpha, and IL-10 may improve clinical diagnosis of PAS in placenta previa cases. Cytokines may be used as additional biomarkers to the clinical risk factors in the diagnosis of PAS.

Microcellular approach for the pathogenesis of placenta accreta spectrum inflammatory versus apoptotic pathways; a thorough look on Treg, dNK and VEGF

Placenta accreta spectrum (PAS) is a disorder of irregular placental invasion to the surrounding structures, it is a leading cause of maternal morbidity and mortality. This study was theorized to perceive the role of Treg cells and VEGF which appealed to play a role in the pathogenesis of nonstandard extreme placental invasion. The study was carried out on 40 pregnant women; Group I (control group), and Group II (placenta accrete spectrum PAS). Light microscopic, immune-histochemical; CD 56 (NK CELLS) and CD 45 RO (T reg) western blot; P53 and VEGF morphometry and statistical analysis were done. H&E-stained sections revealed Placental tissue in unswerving contact with the myometrium, deficient decidual layer, hemorrhage, congested edematous blood vessels. The mean area percent of collagen, Treg, P53, and VEGF exposed a significant increase in the placenta accreta group when compared to that of control women. Nonetheless, the mean area percent of NK cells displayed a significant decrement PAS cases are associated with low levels of NK cells and increased levels of Treg cells, P 53, and VEGF, promoting the hyperinvasive behavior of trophoblasts of placenta accreta and dysregulate placental vascular remodeling.

Clinical and Histological Associations of Chronic Inflammatory Lesions in Preterm Placentas: Uncovering the Hidden Dangers

BACKGROUND

Chronic placental inflammatory lesions (CPIL) include chronic deciduitis (CD), villitis of unknown etiology (VUE), and chronic chorioamnionitis (CCA). The frequency of these lesions and their relationship with various clinicopathological parameters in preterm birth (PTB) is presented.

MATERIAL AND METHODS

Preterm placentas from April 2018 to December 2020 were reviewed for presence of CPIL. PTB was classified as spontaneous, indicated, or mixed phenotype. The association of CPIL with clinical parameters like gestational age, birth weight, obstetric complications, and placental parameters like placental dimensions, weight, vascular malperfusion, acute inflammatory lesions, and basal plate myometrial fibers were analyzed.

RESULTS

The study included 538 preterm placentas with 54.3% from indicated PTB. CD was more common (28.4%) than VUE (17.8%) and CCA (12.6%). CD showed significant association with VUE and CCA (both P = .0001) and VUE with CCA (P = .0001). CD was more common in indicated PTB (33.8%, P = .002) and associated with lower birth weight (1591 g vs 1705 g, P = .003), lower placental weight (270.7 g vs 296.9 g, P = .004), length (14.2 cm vs 14.8 cm, P = .006), breadth (11.7 cm vs 12.2 cm, P = .007), maternal vascular malperfusion (P = .004), and basal plate myometrial fibers (P = .02). High-grade and multifocal low-grade VUE was associated with reduced placental length (13.9 cm vs 14.6 cm, P = .02)and breadth (11.5 cm vs 12.1 cm, P = .01). CCA did not show any other association.

CONCLUSION

CPIL are common in PTB and their coexistence suggested a common pathogenic mechanism. Placental examination is the only definite way to identify as they lack clinical signs and symptoms. The smaller placental size associated with these lesions may suggest alter mechanisms for adverse pregnancy outcomes.

The Association of Serum Midkine Level with Invasion in Placenta Previa: A Case-Control Study from a Tertiary Reference Center

We aimed to examine the relationship between serum midkine levels and placental invasion in pregnant women with placenta previa. The study group consisted of 43 pregnant women diagnosed with placenta previa, whereas the control group consisted of 60 healthy pregnant women. Serum midkine levels were compared between pregnant women with placenta previa and the control group in this study's first part. Thereafter, the utility of midkine in the prediction of the abnormally invasive placenta (AIP) was investigated and optimal cutoff values were calculated. Significantly higher serum midkine level was observed in placenta previa cases than in the controls (1.16 ng/mL vs. 0.18 ng/mL, P < 0.001). Serum midkine level was also significantly higher in the AIP group among the placenta previa cases (P = 0.004). In the receiver operating characteristic analysis, the cutoff value of the midkine level in predicting AIP was 1.19 ng/mL. This study revealed that the serum midkine level is higher in pregnant women with AIP. Maternal serum midkine level may be used as a complementary biomarker to the radiological and clinical findings for the prediction of the AIP in placenta previa cases.

Expression of sirtuin 2 and 7 in placenta accreta spectrum

OBJECTIVE

This study aimed to investigate the expression levels of sirtuin 2 and sirtuin 7 in the placenta accreta spectrum to reveal their role in its pathogenesis.

METHODS

A total of 30 placenta accreta spectrum, 20 placenta previa, and 30 controls were experienced. The sirtuin 2 and sirtuin 7 expression levels in the placentas of these groups were determined by Western blot. sirtuin 2 and sirtuin 7 serum levels in the maternal and fetal cord blood were examined by enzyme-linked immunosorbent assay.

RESULTS

It was found that sirtuin 7 in placenta accreta spectrum was significantly lower in the placenta compared to the control and placenta previa groups (p<0.05). However, a significant difference was not observed between the sirtuin 2 and sirtuin 7 levels in the maternal and fetal cord serum samples of those three groups (p>0.05).

CONCLUSION

Sirtuin 7 may play an important role in the formation of placenta accreta spectrum. The effect of decreased expression of sirtuin 7 might be tissue-dependent in the placenta accreta spectrum and needs to be investigated further.

Implementation and outcomes of a uterine artery embolization and tranexamic acid protocol for placenta accreta spectrum

BACKGROUND

Placenta accreta spectrum disorders are a continuum of placental pathologies with significant maternal morbidity and mortality. Morbidity is related to the overall degree of placental adherence, and thus patients with placenta increta or percreta represent a high-risk category of patients. Hemorrhage and transfusion of blood products represent 90% of placenta accreta spectrum morbidity. Both tranexamic acid and uterine artery embolization independently decrease obstetrical hemorrhage.

OBJECTIVE

This study aimed to provide an evidence-based intraoperative protocol for placenta accreta spectrum management.

STUDY DESIGN

This study was a pre- and postimplementation analysis of concomitant uterine artery embolization and tranexamic acid in cases of patients with antenatally suspected placenta increta and percreta over a 5-year period (2018-2022). For comparison, a 5-year (2013-2017) preimplementation group was used to assess the impact of the uterine artery embolization and tranexamic acid protocol for placenta accreta spectrum. Patient demographics and clinically relevant outcomes were obtained from electronic medical records.

RESULTS

A total of 126 cases were managed by the placenta accreta spectrum team, of which 66 had suspected placenta increta/percreta over the 10-year time period. Two patients were excluded from the postimplementation cohort because they did not undergo both interventions. Thus, 30 (30/64; 47%) were treated after implementation of the uterine artery embolization and tranexamic acid protocol for placenta accreta spectrum, and 34 (34/64; 53%) preimplementation patients did not undergo uterine artery embolization or tranexamic acid infusion. With the uterine artery embolization and tranexamic acid protocol, operative times were longer (416 vs 187 minutes; P<.01), and patients were more likely to receive general anesthesia (80% vs 47%; P<.01). However, blood loss was reduced by 33% (2000 vs 3000 cc; P=.03), overall blood transfusion rates decreased by 51% (odds ratio, 0.05 [95% confidence interval, 0.001-0.20]; P<.01), and massive blood transfusion (>10 units transfused) was reduced 5-fold (odds ratio, 0.17 [95% confidence interval, 0.02-0.17]; P=.02). Postoperative complication rates remained unchanged (4 vs 10 events; P=.14). Neonatal outcomes were equivalent.

CONCLUSION

The uterine artery embolization and tranexamic acid protocol for placenta accreta spectrum is an effective approach to the standardization of complex placenta accreta spectrum cases that results in optimal perioperative outcomes and reduced maternal morbidity.

Ferumoxytol-enhanced MR demonstration of changes to internal placental structure in placenta accreta spectrum: Preliminary findings

INTRODUCTION

The goal of this pilot study is to determine if ferumoxytol-enhanced MR might provide a new approach to the diagnosis of placenta accreta spectrum (PAS), and if so, to identify signs of PAS.

METHODS

Ten pregnant women were referred for MRI evaluation for PAS. MR studies consisted of pre-contrast SSFSE, SSFP, DWI, and ferumoxytol-enhanced sequences. Post-contrast images were rendered as MIP and MinIP images to separately display the maternal and fetal circulations respectively. Two readers examined the images for architectural changes to placentone (fetal cotyledon) that might distinguish PAS cases from normal. Attention was given to the size and morphology of the placentone, villous tree, and vascularity. In addition, the images were examined for evidence of fibrin/fibrinoid, intervillous thrombus, basal and chorionic plate bulges. Interobserver agreement was characterized with kappa coefficients and levels of confidence for feature identification was recorded on a 10-point scale.

RESULTS

At delivery, there were five normal placentas and five with PAS (one accreta, two increta, two percreta). The ten changes of placental architecture in PAS included: focal/regional expansion of placentone(s); lateral displacement and compression of the villous tree; disruption of a regular pattern of normal placentones; bulging of the basal plate; bulging of the chorionic plate; transplacental stem villi; linear/nodular bands at basal plate; non-tapering villous branches; intervillous hemorrhage; and dilated subplacental vessels. All these changes were more common in PAS; the first five achieved statistical significance in this small sample. The interobserver agreement and confidence for the identification of these features was good to excellent except for dilated subplacental vessels.

DISCUSSION

Ferumoxytol-enhanced MR imaging appears to depict derangements of the internal architecture of placentas with PAS, thereby suggesting a promising new strategy to diagnose PAS.

Characterization of cord blood CD3+ TCRVα7.2+ CD161high T and innate lymphoid cells in the pregnancies with gestational diabetes, morbidly adherent placenta, and pregnancy hypertension diseases

PROBLEM

Although pregnant women with gestational diabetes (GD), morbidly adherent placenta (MAP), and pregnancy hypertension (pHT) diseases lead to intrauterine growth restriction (IUGR), little is known about their effect on mucosal-associated invariant T (MAIT) and innate lymphoid cells (ILC) in the umbilical cord. This study aimed to quantify and characterize MAIT cells and ILCs in the cord blood of pregnant women with GD, MAP, and pHT diseases.

METHOD OF STUDY

Cord blood mononuclear cells (CBMCs) were isolated by Ficoll-Paque gradient. CD3⁺ TCRVα7.2⁺ CD161^high cells and ILC subsets were quantified by flow cytometry. CBMCs were stimulated with PMA/Ionomycin and Golgi Plug for 4 h and stained for IFN-γ, TNF-α, and granzyme B. The stained cells were analyzed on FACS ARIA III.

RESULTS

Compared with healthy pregnancies, in the cord blood of the pHT group, elevated number of lymphocytes was observed. Moreover, the absolute number of IFN-γ producing CD4⁺ or CD4^- subsets of CD3⁺ TCRVα7.2⁺ CD161^high cells as well as those producing granzyme B were significantly elevated in the pHT group compared to healthy controls suggesting increased MAIT cell activity in the pHT cord blood. Similarly, in the MAP group, the absolute number of total CD3⁺ TCRVα7.2⁺ CD161^high cells, but not individual CD4⁺ or negative subsets, were significantly increased compared with healthy controls' cord blood. Absolute numbers of total CD3⁺ TCRVα7.2⁺ CD161^high cells and their subsets were comparable in the cord blood of the GD group compared with healthy controls. Finally, the absolute number of total ILCs and ILC3 subset were significantly elevated in only pHT cord blood compared with healthy controls. Our data also reveal that IFN-γ⁺ or granzyme B⁺ cell numbers negatively correlated with fetal birth weight.

CONCLUSIONS

CD3⁺ TCRVα7.2⁺ CD161^high cells and ILCs show unique expansion and activity in the cord blood of pregnant women with distinct diseases causing IUGR and may play roles in fetal growth restriction.

Systemic immune-inflammation index to predict placenta accreta spectrum and its histological subtypes

AIM

In this study, we aimed to investigate the role of systemic immune-inflammation index (SII) and other inflammatory parameters in the diagnosis of placenta accreta spectrum (PAS) and its histological subtypes.

METHODS

This retrospective case-control study included patients who underwent surgery for placenta previa (PP). Case group (patients with PAS) included pregnant women diagnosed with histologically confirmed PAS, whereas control group (patients with PP) included pregnant women who underwent cesarean section with a PP diagnosis, required no additional intervention during the operation. Both groups were compared with respect to their demographic data, clinical characteristics, SII, and other laboratory parameters. Cut-off values that can predict PAS were calculated. The PAS group was separated into subgroups based on histology findings, and inflammatory parameters were compared between subgroups.

RESULTS

In this study, data of 273 patients were analyzed. Of these, 68 (24.9%) were included in the PAS group and 205 (75.1%) patients were included in the PP group. Significant differences were observed in SII, platelet distribution width, mean platelet volume, neutrophil-to-lymphocyte ratio, and platelet-to-lymphocyte ratio (p = 0.000, p = 0.006, p = 0.002, p = 0.000, and p = 0.000, respectively). The best SII cut-off value was 985.02109/L (57.4% sensitivity and 72.2% specificity). There was no significant association between the histologic subtypes of PAS and inflammatory parameters.

CONCLUSION

SII can be used to predict PAS in pregnant women with PP. The relationship between the histologic subtypes of PAS and inflammatory parameters should be investigated in more comprehensive studies.

Association between placental implantation abnormalities and hypertensive disorders of pregnancy

AIM

This study aimed to investigate the association between placental implantation abnormalities (PIAs) and gestational hypertension-preeclampsia (GH-PE) in pregnant women.

METHODS

Patients were recruited from 2010 to 2019 into this retrospective study at the International Peace Maternity & Child Health Hospital. PIAs were classified as follows: placenta previa (PP), low-lying placenta (LP), placenta accreta, and placenta adherence (PA). Logistic regression models were constructed to analyze the associations between placental abnormalities and GH-PE. Propensity score matching (PSM) was conducted to reduce confounders. The relationship between PP with placenta accreta spectrum (PAS) and GH-PE were assessed.

RESULTS

In total, 5527 women were recruited, and 2614 women had an abnormal placenta (992 with LP; 749 with PP 839 and PA; and 34 with placenta accreta). There were 296 patients with GH-PE in those groups. After adjustments for confounding factors, women with PP had a lower risk of PE (odds ratio [OR]: 0.43; 95% confidence interval [CI]: 0.19-0.86, p = 0.025) than those in the control group. Women with PA had a higher risk of GH-PE (OR: 1.45; 95% CI: 1.05-1.99, p = 0.022). In addition, we categorized PP into marginal, complete, and partial PP and investigated these associations. We found a lower risk of PE in complete PP (OR: 0.09, 95% CI: 0.01-0.44, p = 0.020) than in marginal or partial PP. There was no significant difference regarding GH-PE in the PP with PAS group (OR = 0.67, 95% CI: 0.82-2.34, p = 0.525).

CONCLUSION

PP, especially complete PP, is associated with a lower risk of PE. PA is associated with higher risks of GH-PE.

Delta Neutrophil Index as a Promising Biomarker for Placental Implantation Disorders

OBJECTIVE

We aimed to investigate the value of maternal serum delta neutrophil index (DNI) levels in predicting placenta accreta spectrum in patients with placenta previa.

METHODS

The patients who were found to have placenta previa totalis were included in our study. Location of placental implantation and depth of myometrial invasion were defined by transabdominal and transvaginal 2D gray scale and Doppler sonography and confirmed during cesarean section and histopathological evaluation. Patients were subjected to complete blood counts, including prenatal hemoglobin level, total white blood cell count, differential leukocyte count, and platelet count. The following formula was used to calculate the DNI level: DNI (%)=(leukocyte subfraction analyzed by cytochemical reaction in the MPO channel) - (leukocyte subfraction analyzed using the nuclear lobularity channel with reflected light beam measurements).

RESULTS

Placenta previa was detected in 295 patients; 31 of them had PAS. As the control group, 189 patients were evaluated. In the group with PAS, the DNI value was significantly higher (p<0.05) than the other groups. DNI value in the group with previa only was also significantly higher (p<0.05) than the control group. In the univariate model, a significant (p<0.05) effect of DNI value and number of cesarean sections was observed in separating patients with previa only and PAS. In the multivariate model, a significant independent (p>0.05) effect of the DNI value was observed in separating patients with previa only and PAS. Significant efficiency of DNI value [area under the curve 0.899 (0.814-0.984)] was observed in differentiating patients with previa only and PAS. Significant efficacy of DNI 5 cut-off value [area under the curve 0.858 (0.770-0.946)] was observed in distinguishing patients with previa only and PAS (sensitivity 80.0%, positive predictive value 64.9%, specificity 91.6%, negative predictive value 95.9%) CONCLUSION: Maternal DNI values seem to be beneficial with respect to both previa and invasion prediction. Although more comprehensive studies are needed to test this proposition, prediction studies of this practical test should be done in different trimesters and its usability with respect to preventing maternal-fetal morbidity should be investigated.

Maternal Serum Placental Protein-13 Levels in the Prediction of Pregnancies with Abnormal Invasive Placentation

OBJECTIVE

To evaluate whether placental protein-13 (PP-13) measured in the serum of pregnant women could predict abnormal invasive placentation (AIP) detected by color Doppler ultrasound (US) and magnetic resonance imaging scan in addition to the routine US scan during the third trimester.

MATERIALS AND METHODS

The prospective case-control study included patients subdivided in 2 groups: 42 pregnant women with a singleton pregnancy at 28-32 weeks of gestation with only suspected AIP, and 32 healthy pregnant women. The serum PP-13 levels were measured in both groups using an enzyme-linked immunosorbent assay (ELISA) method and statistically compared. The cases of AIP were confirmed by placental histopathological examination and/or the uterus removed by hysterectomy after elective caesarean section.

RESULTS

Serum PP-13 levels of pregnant women with AIP were significantly higher (p<0.001) than those of controls (650.32±387.33 vs. 231.43±94.33). Statistical analysis of maternal serum PP-13 levels above the threshold of 312 pg/ml (measured in the early third trimester) predicted AIP with 76.2% sensitivity and 75% specificity.

CONCLUSION

Maternal serum PP-13 may have a role in the pathophysiology of AIP owing to its high serum value in the AIP group. The maternal serum dosage of PP-13 levels could improve pregnancy management in those patients suspected of having AIP.

Classification and reporting guidelines for the pathology diagnosis of placenta accreta spectrum (PAS) disorders: recommendations from an expert panel

The terminology and diagnostic criteria presently used by pathologists to report invasive placentation is inconsistent and does not reflect current knowledge of the pathogenesis of the disease or the needs of the clinical care team. A consensus panel was convened to recommend terminology and reporting elements unified across the spectrum of PAS specimens (i.e., delivered placenta, total or partial hysterectomy with or without extrauterine tissues, curetting for retained products of conception). The proposed nomenclature under the umbrella diagnosis of placenta accreta spectrum (PAS) replaces the traditional categorical terminology (placenta accreta, increta, percreta) with a descriptive grading system that parallels the guidelines endorsed by the International Federation of Gynaecology and Obstetrics (FIGO). In addition, the nomenclature for hysterectomy specimens is separated from that for delivered placentas. The goal for each element in the system of nomenclature was to provide diagnostic criteria and guidelines for expected use in clinical practice.

Abnormal placental pathological findings and adverse clinical outcomes of oocyte donation

We sought to assess chronic inflammatory responses in patients who achieved pregnancy by oocyte donation and non-oocyte donation-assisted reproductive technology and delivered at The Ottawa Hospital. Data describing maternal health, obstetrical outcomes, neonatal outcomes, and placental pathology were collected and analyzed from electronic medical records. An increased frequency of adverse obstetrical outcomes was observed. In the oocyte donation-assisted reproductive technology group, placental pathology data demonstrated increased frequency of fetal vascular malperfusion (p = 0.02) and placenta accreta (p < 0.001), representing a chronic inflammatory response. Placental pathology reflecting dysregulated immune processes and vasculopathy is associated with oocyte donation.

Placental Pathology in COVID-19

OBJECTIVES

To describe histopathologic findings in the placentas of women with coronavirus disease 2019 (COVID-19) during pregnancy.

METHODS

Pregnant women with COVID-19 delivering between March 18, 2020, and May 5, 2020, were identified. Placentas were examined and compared to historical controls and women with placental evaluation for a history of melanoma.

RESULTS

Sixteen placentas from patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were examined (15 with live birth in the third trimester, 1 delivered in the second trimester after intrauterine fetal demise). Compared to controls, third trimester placentas were significantly more likely to show at least one feature of maternal vascular malperfusion (MVM), particularly abnormal or injured maternal vessels, and intervillous thrombi. Rates of acute and chronic inflammation were not increased.The placenta from the patient with intrauterine fetal demise showed villous edema and a retroplacental hematoma.

CONCLUSIONS

Relative to controls, COVID-19 placentas show increased prevalence of decidual arteriopathy and other features of MVM, a pattern of placental injury reflecting abnormalities in oxygenation within the intervillous space associated with adverse perinatal outcomes. Only 1 COVID-19 patient was hypertensive despite the association of MVM with hypertensive disorders and preeclampsia. These changes may reflect a systemic inflammatory or hypercoagulable state influencing placental physiology.

[Pathomorphological features of the placentas and the placental sites after in vitro fertilization with a donor egg]

OBJECTIVE

To identify the structural and immunohistochemical features of the placentas and the placental sites after in vitro fertilization (IVF) with a donor egg (surrogate motherhood).

SUBJECT AND METHODS

Morphological and immunohistochemical studies were performed on the placental (a placental disk) and placental bed materials obtained after caesarean delivery. The investigation enrolled 26 patients whose pregnancy occurred with IVF with a donor egg according to the surrogacy (IVF-S) program. A comparison group included 13 patients whose pregnancy occurred after IVF with their own eggs. An immunohistochemical study was conducted on paraffin sections made from biopsy material; mouse antibodies to total cytokeratin (clone AE1/AE3, 'Dako'), HLA-DR (clone TAL.1B5, 'Dako'), and CD138 (clone MI15, 'Dako') were used as primary antibodies.

RESULTS

The histological examination of the placentas in the IVF-S group showed the high incidence of central ischemic heart attacks (69%), dissociated cotyledon development (61%), pathological villous immaturity mainly with the predominance of intermediate differentiated villi (46%), and massive perivillous fibrinoid deposition (73%). The obtained differences between with the study and comparison groups were significant (p<0.05). The IVF-S group was characterized by the development of lymphoplasmacytic deciduitis (1.23±0.4 and 0.5±0.3 scores). Examination of the placental site biopsy material in the IVF-S group revealed the following changes: remodeling of the spiral arteries was incomplete in more than 40% of cases, and in 30% of the spiral arteries had no gestational changes. In the comparison group, more than 90% of the spiral arteries were characterized by complete remodeling during pregnancy. There was also an increase in the count of multinucleated trophoblastic giant cells (104.56±4.21 and 65.67±14.45) and HLA-DR positive cells (41.86±5.32 and 29.00±1.87).

CONCLUSION

The placentas and the placental sites of the women whose pregnancy occurred with IVF-S are characterized by the development of high lyoplasmacytic deciduitis activity and pronounced placental immune alterations manifested by the high incidence of immune responses at the sites of the closest contact between maternal and fetal tissues. The placental bed exhibited defective spiral artery remodeling, development of chronic inflammatory lesions in the perivascular areas, and an increase in the counts of HLA-DR positive cells and multinucleated trophoblastic giant cells.

Immune cell infiltrate at the utero-placental interface is altered in placenta accreta spectrum disorders

PURPOSE

To characterize the immune cell infiltrate associated with maternal vascular remodeling in 12 cases of cesarean hysterectomy from women with placenta accreta spectrum (PAS) disorder.

METHODS

Myometrial vessels were evaluated by hematoxylin and eosin and immunohistochemistry stains on tissue microarrays that included samples from the myometrium, deep to the implantation site. Vessels were quantified based on physiologic conversion and immune cell infiltrates. Placental bed biopsies from cases of repeat cesarean section, and decidual vessels from delivered non-PAS placentas were used as controls.

RESULTS

Immune cells, predominantly macrophages and T-cells, were present as a band along the placental-myometrial interface in PAS cases. However, within the myometrium, the infiltrate showed a perivascular accentuation. The infiltrates around and within vessel walls were composed of T-cells (CD3) and macrophages (CD68), with fewer NK (CD56), Treg (FoxP3) and rare B-cells (CD20). Plasma cells (CD138) were absent. The majority of vessels with immune cell infiltrates had undergone complete or partial physiologic conversion by trophoblast. However, a subset of unconverted vessels in the myometrium had a similar immune cell infiltration. Control blood vessels showed a similar pattern of leukocytes infiltration in the decidua and placental bed biopsies, but with a lower density.

CONCLUSIONS

Our findings suggest that myometrial vascular changes in PAS resemble the physiological changes of vessels noted in the implantation site of normal pregnancies. The presence of perivascular immune cell infiltrates in the absence of adjacent trophoblast suggests that the process may be initiated by paracrine effects rather than direct contact or endovascular growth of trophoblast.

Basal Chronic Villitis and Disorders of the Placental Basal Plate: A Possible Immunological Link Between Hypertensive Disorders of Pregnancy and Morbidly Adherent Placenta

BACKGROUND

Hypertensive disorders of pregnancy (HDP) are a common cause for preterm delivery. Prior studies showed that chronic villitis (CV) is associated with intrauterine growth restriction, preeclampsia, intrauterine fetal death, and morbidly adherent placenta (MAP). The authors hypothesize that disorders of the placental basal plate, especially basal chronic villitis (BCV), are associated with HDP.

METHODS

The laboratory information system was queried over 12 years to identify placentas with or without the clinical history of HDP and with or without multifocal/focal CV or BCV. As a control for tissue sampling, a similar search was performed over 5 years for placentas evaluated for MAP.

RESULTS

Of 19,683 placentas identified, 14.8% had CV which was in 18.5% and 14.2% of placentas associated with or without HDP, respectively, a significant difference (P < .0001). BCV was present in 6.0% and 3.9% of placentas with or without HDP, respectively, also a significant difference (P < .0001). BCV was more likely than multifocal/focal CV to occur in HDP (32.4% vs 27.4%) when all cases of CV were analyzed (P = .025). Of 221 placentas with MAP, 64% had multifocal/focal CV and 36% had BCV.

CONCLUSIONS

BCV and CV are more common in placentas with HDP than in normotensive pregnancies. They are also seen in MAP, as supported by another recent study.

Structural, immunohistochemical and molecular features of placentas and placental sites after in vitro fertilization with donor eggs (surrogate motherhood)

OBJECTIVE

to identify structural, immunohistochemical and molecular features of placentas and placental sites afterin vitro fertilization (IVF) with donor eggs (surrogate motherhood).

STUDY DESIGN

morphological and immunohistochemical studies were performed on placental material obtained after delivery by caesarean section. The study included 26 women patients whose pregnancy resulted from IVF with a donor egg (IVF-SM group). The comparison group included 13 women patients whose pregnancy occurred after IVF with their own eggs (IVF-OE). Immunohistochemistry of biopsy material was performed using mouse antibodies to total cytokeratin (clone AE1/AE3) and murine antibodies to HLA-DR (clone TAL.1B5). Molecular studies were performed on DNA samples isolated from venous blood. HLA-DNA-TEH reagent kits and polymerase chain reaction were used for genotyping the main human histocompatibility complex class II (DQA1, DQB1 and DRB1).

RESULTS

Histological examination of placenta in IVF-SM group showed a high incidence of central ischemic infarctions (69% of cases), dissociated cotyledon development (61%), pathological villus immaturity (46%) and massive perivillous fibrin deposition (73%). This group also had a pronounced lymphoplasmacytic deciduitis, which was 2 times higher than in the control group, and an expressed inflammatory process in the placental sites. Remodeling of the spiral arteries was incomplete in more than 40% of cases, and 30% of spiral arteries had no gestational changes. In comparison group, a complete gestational adjustment was found in more than 90% of spiral arteries. A focal lymphohistiocytic infiltration in perivascular regions, and a decrease in the number of multinucleated cells as compared with the control were also observed. For seven female surrogate mothers and their children, allelic polymorphisms of genes of HLA II class were studied.

CONCLUSION

Placental material of women from IVF-SM group is characterized by complex immune response in sites of tight contact between maternal and fetal tissues. The immune pathogenesis is associated with an increase in the number of HLA-DR positive cells, defects in remodeling of the spiral arteries, development of areas of chronic inflammation in perivascular regions, and a decrease in the number of multinucleated cells. Genetic incompatibility between alleles of HLA II genes can be a molecular predictor of impaired immune tolerance.

Histological Features of Shallow Placental Implantation Unify Early-Onset and Late-Onset Preeclampsia

Preeclampsia is distinguishable from other hypertensive conditions of pregnancy by its high rates of decidual arteriopathy, the uterine type of chronic hypoxic placental injury, the occurrence of villous infarctions, and clusters of multinucleate trophoblasts in the maternal floor. To retrospectively study the clinical and placental phenotypes of 230 women with early-onset preeclampsia, 261 women with late-onset preeclampsia, and 5059 women without hypertension in pregnancy (comparative group), 24 clinical and 46 placental phenotypes were statistically compared (analysis of variance, χ² with Bonferroni correction). The frequency of decidual arteriopathy (both hypertrophic and atherosis), patterns of chronic hypoxic placental injury, villous infarction, membrane laminar necrosis, membrane microscopic chorionic pseudocysts, clusters of maternal floor multinucleated trophoblasts, excessive number of extravillous trophoblasts, and intervillous thrombi was strikingly higher in both late-onset preeclampsia and early-onset preeclampsia than in the comparative group without hypertension in pregnancy. All 3 patterns of chronic hypoxic placental injury were 2- to 3-fold more common in preeclampsia. Although the preuterine pattern was as common in early-onset preeclampsia as it was in late-onset preeclampsia, the postuterine pattern was 2-fold more common in early-onset preeclampsia, and chronic villitis of unknown etiology was more common in late-onset preeclampsia than in the other 2 groups. Features of shallow placental implantation occurred at the same frequency in early-onset preeclampsia as in late-onset preeclampsia, which reflects an underlying common pathological mechanism in both subgroups of preeclampsia, while hypoxic lesions and patterns of placental injury were more common in early-onset preeclampsia than in late-onset preeclampsia, which correlates with more severe clinical outcomes of the former.

Recurrence of Basal Plate Myofibers, with Further Consideration of Pathogenesis

OBJECTIVES

Basal plate myofibers (BPMF) may indicate morbid adherence. We assessed recurrence and clinical progression of BPMF.

METHODS

In 5 years, 135 BPMF placentas were reported. Controls were the first 50 placentas in 2009, none of which had reported BPMF.

RESULTS

32% of BPMF patients had other placentas, with a recurrence rate of 100%. Actin stains were needed for diagnosis in 117/179 cases (65%). These cases had clinical features suggestive of morbid adherence in 69/117 (59%). 23/47 (49%) of BPMF recurrences progressed in severity, 5 to hysterectomy (11%). Thinning of the basal plate, perforating vessels, gaps in the basal plate, and villi under the basal plate were observed in BPMF placentas.

CONCLUSIONS

These findings appear to validate screening for BPMF. The 100% recurrence rate suggests evaluation for a heritable factor, i.e., protease inhibitor deficiency, which may explain pre-delivery basal plate damage.

Chorion laeve accreta - Another manifestation of morbid adherence

INTRODUCTION

Smooth muscle in the decidua of fetal membranes (membrane myofibers, MMF) is not mentioned in standard textbooks.

METHODS

The current report presents collected observations on 52 patients with MMF at 2 institutions between 2004 and 2017 - including placentas, postpartum curettages, and hysterectomies.

RESULTS

Clinical presentations include observation of adherent membranes during delivery, disrupted and incomplete membranes in placentas submitted for examination, postpartum bleeding associated with retained fetal membranes, association with membrane hematomas and membrane hemosiderin, morbidly adherent fetal membranes in hysterectomies; and association with grossly adherent pieces of tissue or nodules in fetal membranes.

DISCUSSION

Although MMF can be an incidental microscopic observation in a routine placenta, the suggested diagnostic terminology when there are clinical and/or gross presentations is Chorion Laeve Accreta (ChLA). Further study is needed but MMF appears to be the fetal membrane counterpart of BPMF(basal plate myofibers), possibly due to damage of subjacent myometrium by trophoblastic proteases, so that shear stress during delivery causes myofibers to come out attached to the decidua of fetal membranes. Neither the prevalence of MMF, nor its reliability as a marker for placenta accreta is addressed in this collection. Association of MMF with BPMF, and recurrence of MMF, are documented; but the true frequency of these phenomena remains to be established.

Placenta Accreta Spectrum: A Review of Pathology, Molecular Biology, and Biomarkers

Background. Placenta accreta spectrum (PAS) is a condition of abnormal placental invasion encompassing placenta accreta, increta, and percreta and is a major cause of severe maternal morbidity and mortality. The diagnosis of a PAS is made on the basis of histopathologic examination and characterised by an absence of decidua and chorionic villi are seen to directly adjacent to myometrial fibres. The underlying molecular biology of PAS is a complex process that requires further research; for ease, we have divided these processes into angiogenesis, proliferation, and inflammation/invasion. A number of diagnostic serum biomarkers have been investigated in PAS, including human chorionic gonadotropin (HCG), pregnancy-associated plasma protein-A (PAPP-A), and alpha-fetoprotein (AFP). They have shown variable reliability and variability of measurement depending on gestational age at sampling. At present, a sensitive serum biomarker for invasive placentation remains elusive. In summary, there are a limited number of studies that have contributed to our understanding of the molecular biology of PAS, and additional biomarkers are needed to aid diagnosis and disease stratification.

Association of Retroplacental Blood With Basal Plate Myofibers

Objectives Diagnosed clinical abruption showing blood clot should be signed out in the pathology report as retroplacental hemorrhage with or without parenchymal indentation, and submitted clot separate from the placenta should be weighed. In our experience, some cases sent as clinical abruptions have been cases of morbid adherence. This study was undertaken to evaluate the association of retroplacental blood with basal plate myofibers (BPMF). Methods One hundred fifty-six placentas reviewed by a board-certified pediatric pathologist at a community hospital were evaluated for significant retroplacental blood. Basal plates were reviewed for deviations from normal. Results Of the 156 placentas, 33 (21%) had significant retroplacental blood; 21/156 (13%) had a separate clot, of which 11/21 (52%) had BPMF. Eleven BPMF-associated separate clots ranged from 10.5 to 60 g (average 23), while the clots of 10 cases with no demonstrated BPMF ranged from 19 to 440 g (average 82), tending to be larger ( p < .03). Basal plate damage prior to delivery was noted in both sets of placentas. BPMF placentas could have myometrial damage prior to delivery. Conclusions Since BPMF may confer a risk for accreta in a subsequent pregnancy, submission of a separate clot with the placenta should lead the pathologist to evaluate for basal plate myofibers on H&E and consider if there is an evidence-based indication to do an actin stain, before presuming a diagnosis of abruption.