Decidual Vasculopathy: Placental Location and Association With Ischemic Lesions

The association between decidual vasculopathy and abnormal uterine artery Doppler measurement

INTRODUCTION

Placental syndrome is an umbrella term encompassing the clinical phenotypes of preeclampsia and fetal growth restriction, and is associated with high maternal and neonatal morbidity. In women with placental syndrome, histologicl examination of the uteroplacental unit commonly demonstrates pathological lesions, such as decidual vasculopathy. Decidual vasculopathy are pathological changes in the spiral arteries, which are associated with adverse outcome in preeclampsia and long-term maternal cardiovascular health. The relation between placental syndrome phenotypes and placental pathology has been previously demonstrated; however, the role of uteroplacental Doppler measurements as a link between placental syndrome phenotypes and the underlying placental pathology is still unclear. We hypothesized that decidual vasculopathy is associated with abnormal uteroplacental Doppler profiles and ultrasound placental parameters, independent of clinical phenotype.

MATERIAL AND METHODS

We performed a retrospective analysis of data from a prospective cohort of pregnancies with placental syndrome, as well as cases without hypertensive disease or fetal growth restriction. The study group was divided into women with decidual vasculopathy on histologic analysis of placental specimen and those without the lesions. Outcome parameters included maternal and fetal Dopplers, estimated fetal weight, placental weight and thickness, placental lacunae and abnormal placental calcification.

RESULTS

Compared with the women without the lesions (n = 91), the group with decidual vasculopathy (n = 25) had a higher mean uterine artery pulsatility index (1.70 vs 0.81, p < 0.001) and uterine artery pulsatility index percentile (>p99 vs p67, p < 0.001). Decidual vasculopathy was associated with abnormal uterine artery Doppler profile (defined as pulsatility index p > 95 and/or bilateral notch) (82%) compared with women without the lesions (33%) (odds ratio [OR] 9.3, 95% CI 2.4-36.0), which remained significant after adjusting for possible confounding factors preeclampsia, tobacco use and gestational age at birth (OR 7.1, 95% CI 1.3-39.1). Decidual vasculopathy was not associated with fetal Doppler abnormalities or placental parameters and only modestly so with lower cerebroplacental ratio (p = 0.036).

CONCLUSIONS

Histologic decidual vasculopathy is associated with abnormal uterine artery Doppler, independent of clinical phenotype during pregnancy.

Phenotypic Switch of Endovascular Trophoblasts in Decidual Vasculopathy with Implication for Preeclampsia and Other Pregnancy Complications

BackgroundThis study aims to investigate decidual vasculopathy in preeclampsia at term and its relationship to spiral artery remodeling at implantation sites. Study design: Implantations sites with endovascular trophoblasts were reviewed from abortions with immunostaining for CD56. Placentas from patients with preeclampsia were also reviewed in association with other pathological features using placentas with decidual vasculopathy but not preeclampsia as controls. Results: Endovascular trophoblasts were phenotypically switched to express CD56 upon entering the spiral artery at implantation. CD56 expression is identified in classic decidual vasculopathy at term with or without preeclampsia. CD56 expression in addition to cytokeratin in decidual vasculopathy demonstrated the fetal trophoblastic origin, establishing the presence of endovascular trophoblasts at implantation and the decidual vasculopathy at term. Conclusion: Decidual vasculopathy at term contains the same CD56 positive extravillous endovascular trophoblasts seen with spiral artery remodeling in early pregnancy. CD56 may serve as a possible marker for decidual vasculopathy in the later stages of pregnancy.

Placental decidual arteriopathy and vascular endothelial growth factor A (VEGF-A) expression among women with and without HIV

BACKGROUND

Women with HIV (WHIV) are at higher risk of adverse birth outcomes. Proposed mechanisms for the increased risk include placental arteriopathy (vasculopathy) and maternal vascular malperfusion (MVM) due to antiretroviral therapy (ART) and medical comorbidities. However, these features and their underlying pathophysiologic mechanisms have not been well characterized in WHIV.

METHODS

We performed gross and histologic examination and immunohistochemistry staining for vascular endothelial growth factor A (VEGF-A), a key angiogenic factor, on placentas from women with one or more MVM risk factors including: weight <5 th percentile, histologic infarct or distal villous hypoplasia, nevirapine-based ART, hypertension, and pre-eclampsia/eclampsia during pregnancy. We compared pathologic characteristics by maternal HIV serostatus.

RESULTS

A total of 27/41 (66%) placentas assessed for VEGF-A were from WHIV. Mean maternal age was 27 years. Among WHIV, median CD4 T-cell count was 440 cells/mm 3 and HIV viral load was undetectable in 74%. Of VEGF-A stained placentas, both decidua and villous endothelium tissue layers were present in 36 (88%). VEGF-A was detected in 31/36 (86%) with decidua present, and 39/40 (98%) with villous endothelium present. There were no differences in VEGF-A presence in any tissue type by maternal HIV serostatus (P=0.28-1.0). MVM was more common in placentas selected for VEGF-A staining (51 versus 8%, P<0.001).

CONCLUSIONS

VEGF-A immunostaining was highly prevalent, and staining pattern did not differ by maternal HIV serostatus among those with MVM risk factors, indicating the role of VEGF-A in placental vasculopathy may not differ by maternal HIV serostatus.

Decidual Vasculopathy and Spiral Artery Remodeling Revisited III: Hypoxia and Re-oxygenation Sequence with Vascular Regeneration

Aim: Spiral artery remodeling at early pregnancy is characterized by two distinct mechanisms with two morphologic features, namely, trophoblastic-dependent vascular invasion with “plugging”, and trophoblastic-independent mural muscular hypertrophy/hyperplasia, both of which lead to the blocking or narrowing of the arterial lumen with the consequence of reduced maternal blood flow to the developing embryo. Methods: Review of historic literature in light of the new discovery of CD56 (NCAM) expression on endovascular trophoblasts at late gestation, in relation to placental lateral growth with vascular regeneration. Results: Reduced maternal blood flow to the embryo results in a hypoxic condition critical for trophectoderm differentiation and proliferation. Hypoxia is also important for the development of hemangioblasts of vasculogenesis, and hematopoiesis of the placental villi. Up to 13 weeks, both uteroplacental and fetoplacental circulations are established and hypoxic condition relieved for normal fetal/placenta development by ultrasonography. The persistence of trophoblastic plugging and/or mural muscular hypertrophy/hyperplasia leads to persistent reduced maternal blood flow to the placenta, resulting in persistent hypoxia and increased angiogenesis, with a constellation of pathologic features of maternal vascular malperfusion atlate gestation. Wilm’s tumor gene (WT1) expression appears to be central to steroid and peptide hormonal actions in early pregnancy, and vascular regeneration/restoration after pregnancy. Conclusions: Spiral artery remodeling at early pregnancy leads to hypoxia with vascular transformation, and the establishment of uteroplacental circulation results in relief of hypoxia. The hypoxia–re-oxygenation sequence may provide insights into the mechanism of normal fetal/placental development and associated pregnancy complications, such as preeclampsia.

Understanding decidual vasculopathy and the link to preeclampsia: A review

Preeclampsia is the archetype of a spectrum of clinical disorders related to abnormal placental development or function, characterized by placental histological lesions. Among those lesions, decidual vasculopathy is a term used to describe lesions of maternal spiral arteries, which are encountered on placental examination in about half of the women with preeclampsia. The morphological features of the lesions include perivascular lymphocytic infiltration, fibrinoid necrosis and foam cell incorporation within the vessel wall. Due to the resemblance of the latter characteristic to atherosclerosis, they are alternatively termed acute atherosis. Decidual vasculopathy correlates with worse maternal and neonatal outcomes, as well as placental pathology. In this article, we review the available literature on decidual vasculopathy and address the pitfalls in histological analysis of the lesions, including the varying definitions of the lesions and sample collection methods. We also discuss the current evidence on the etiology of the lesions and propose a novel hypothesis linking the three etiological pathways to the formation of decidual vasculopathy and, ultimately, the emergence of the heterogeneous group of placental dysfunction disorders, known as the great obstetric syndromes.

Decidual vasculopathy and spiral artery remodeling revisited II: relations to trophoblastic dependent and independent vascular transformation

Background: There are three types of decidual vasculopathy at term, acute atherosis, fibrinoid medial necrosis, and mural arterial hypertrophy with two separate mechanisms. Acute atherosis and fibrinoid medial necrosis demonstrate the replacement of the muscular wall by the fibrinoid material and "foamy cells", whereas mural arterial hypertrophy depicts thickened hypertrophic muscular wall with a narrowed lumen.Methods: In this review, decidual vasculopathy is reexamined using the knowledge of CD56 expression on endovascular trophoblasts (EVTs) at term with perspective in diagnosis and pathogenesis.Results: All three types of vasculopathy can be identified in both decidua basalis and decidua vera (capsularis/parietalis) at term. Decidual vasculopathy at basalis is related to the persistence of EVTs in spiral artery remodeling at implantation and phenotypic switch to express CD56. However, no trophoblastic invasion of spiral artery is present at decidua vera. At implantation, the spiral artery undergoes a trophoblastic-dependent remodeling in decidua basalis whereas the spiral artery undergoes trophoblastic-independent remodeling in decidual vera.Conclusions: Decidual vasculopathy at term is related to spiral artery remodeling at implantation and this is associated with factors other than trophoblastic invasion alone. The spiral artery remodeling at implantation and pathogenesis of decidual vasculopathy at term is likely through circulating factors in relation to complex physiological and pathological conditions in pregnancy.