Antenatal suspicion of ischemic placental disease and coexistence of maternal and fetal placental disease: analysis of over 500 cases

High-Grade Fetal Vascular Malperfusion Is Associated With Diffuse Chorionic Hemosiderosis

INTRODUCTION

Diffuse chorionic hemosiderosis (DCH) is an abnormality of the placental membranes characterized by the deposition of iron pigment. It is usually secondary to recurrent venous bleeding in early pregnancy. In many papers, it is associated with pre-term delivery. Fetal vascular malperfusion (FVM) is an abnormality of the feto-placental circulation that may be seen at any stage of gestation, but most often in the third trimester. It may be graded as low grade (LGFVM) or high grade (HGFVM). No link has been identified in the placental literature between DCH and FVM, but we have noted the 2 co-existing in placentas submitted for analysis. This study explored a possible association of these 2 entities.

METHODS

Laboratory records were searched for singleton cases coded as DCH based on diagnosis on H&E stain over a 6-year period. Of 4478 placentas reported, 66 cases were coded as DCH (1.5%). These were classified as showing HGFVM, LGFVM, or no FVM. Controls (n = 132) were gestational age-matched cases without DCH. Cord length, coiling, insertion, or other abnormalities were noted. Membranes were classified as normal or circumvallate. Results were analyzed using Graphpad.

RESULTS

Gestation ranged between 16 and 41 weeks gestation. 14/66 (21%) cases of DCH showed HGFVM and 2/66 (3%) showed LGFVM. 16/132 (12%) controls showed HGFVM and 21/132 (15.9%) had LGFVM. Where FVM is present, high-grade FVM is significantly associated with DCH versus controls (P < .0031 Fischer's Test).

DISCUSSION

HGFVM occurs significantly more often in placentas with DCH than in controls. Both FVM and DCH are associated with adverse perinatal outcomes, and a possible relationship between the 2 remains to be clarified.

Invited Commentary: Intermittent Opioid Use and Ischemic Placental Disease-Clarifying Associations With Adverse Pregnancy Outcomes

Discomfort and, to a lesser extent, pain are common complaints during pregnancy, and some patients may turn to opioids for pain relief. Esposito et al. (Am J Epidemiol. 2022;191(5):759-768) report associations between intermittent exposure to opioids during pregnancy and the risk of ischemic placental disease-a syndrome that includes preeclampsia, placental abruption, births that are small for gestational age, and preterm delivery. They found that early opioid exposure in pregnancy was associated with a modestly increased risk for abruption, births that are small for gestational age, and preterm delivery, and both early and late exposures were associated with the greatest risk for these outcomes. Surprisingly, preeclampsia was not associated with opioid use. Through quantitative bias analysis, the authors cleverly tackle a number of biases to assess their roles in explaining the associations, including unmeasured confounding, outcome misclassification, and residual confounding; none exerted strong influences on the associations. Although the findings appear fairly robust on the surface, the lack of association between intermittent opioid use and preeclampsia, and important differences in characteristics of patients in the opioid-exposed group compared with the unexposed group, suggest that further study is needed to clarify the relationship between intermittent opioid use, lifestyle factors, and ischemic placental disease risk.

Fetal vascular malperfusion (FVM): diagnostic implications and clinical associations

INTRODUCTION

Fetal vascular malperfusion (FVM) is diagnosed by the presence of vascular lesions in the muscularized fetal vessels in the placenta and the resultant changes in the downstream villi. The Amsterdam Placental Working Group recognizes two patterns of FVM namely segmental and global. The aim of this study was to estimate the frequency of FVM lesion in our population and to understand its neonatal associations.

METHODS

Fifty-four placentas with FVM and 56 controls collected over 34 months. The maternal and neonatal details were collected from the case charts. The patterns and grades of FVM lesions were related to the clinical factors and significance analyzed statistically using the Chi-square test and t-test and p < .05 was considered significant.

RESULTS

The frequency of FVM was 8.7%. The FVM group showed lower mean gestational age, birth weight, and placental weight with a higher frequency of IUGR. Poor neonatal survival, non-reassuring fetal status, neurological abnormalities, neonatal sepsis, asphyxia, low Apgar, and respiratory support requirement were significantly higher in the FVM group. A similar frequency of segmental and global lesions was seen. High grade lesions (n = 35) were common than low grade (n = 19). Neonatal associations were more often seen in segmental and high-grade lesions.

DISCUSSION

In the absence of antenatal diagnostic tools to identify FVM, placental examination is critical and the only definitive method to diagnose FVM, which alerts the clinician to monitor for several neonatal morbidities. Identification and typing the lesion as per the new guidelines proves significant risk associations with specific types of FVM.

Use of a flexible optical fibre bundle to interrogate a Fabry-Perot sensor for photoacoustic imaging

Photoacoustic imaging systems based on a Fabry Perot (FP) ultrasound sensor that is read-out by scanning a free-space laser beam over its surface can provide high resolution photoacoustic images. However, this type of free-space scanning usually requires a bulky 2-axis galvanometer based scanner that is not conducive to the realization of a lightweight compact imaging head. It is also unsuitable for endoscopic applications that may require complex and flexible access. To address these limitations, the use of a flexible, coherent fibre bundle to interrogate the FP sensor has been investigated. A laboratory set-up comprising an x-y scanner, a commercially available, 1.35 mm diameter, 18,000 core flexible fibre bundle with a custom-designed telecentric optical relay at its distal end was used. Measurements of the optical and acoustic performance of the FP sensor were made and compared to that obtained using a conventional free-space FP based scanner. Spatial variations in acoustic sensitivity were greater and the SNR lower with the fibre bundle implementation but high quality photoacoustic images could still be obtained. 3D images of phantoms and ex vivo tissues with a spatial resolution and fidelity consistent with a free-space scanner were acquired. By demonstrating the feasibility of interrogating the FP sensor with a flexible fibre bundle, this study advances the realization of compact hand-held clinical scanners and flexible endoscopic devices based on the FP sensing concept.

New development of the yolk sac theory in diabetic embryopathy: molecular mechanism and link to structural birth defects

Maternal diabetes mellitus is a significant risk factor for structural birth defects, including congenital heart defects and neural tube defects. With the rising prevalence of type 2 diabetes mellitus and obesity in women of childbearing age, diabetes mellitus-induced birth defects have become an increasingly significant public health problem. Maternal diabetes mellitus in vivo and high glucose in vitro induce yolk sac injuries by damaging the morphologic condition of cells and altering the dynamics of organelles. The yolk sac vascular system is the first system to develop during embryogenesis; therefore, it is the most sensitive to hyperglycemia. The consequences of yolk sac injuries include impairment of nutrient transportation because of vasculopathy. Although the functional relationship between yolk sac vasculopathy and structural birth defects has not yet been established, a recent study reveals that the quality of yolk sac vasculature is related inversely to embryonic malformation rates. Studies in animal models have uncovered key molecular intermediates of diabetic yolk sac vasculopathy, which include hypoxia-inducible factor-1α, apoptosis signal-regulating kinase 1, and its inhibitor thioredoxin-1, c-Jun-N-terminal kinases, nitric oxide, and nitric oxide synthase. Yolk sac vasculopathy is also associated with abnormalities in arachidonic acid and myo-inositol. Dietary supplementation with fatty acids that restore lipid levels in the yolk sac lead to a reduction in diabetes mellitus-induced malformations. Although the role of the human yolk in embryogenesis is less extensive than in rodents, nevertheless, human embryonic vasculogenesis is affected negatively by maternal diabetes mellitus. Mechanistic studies have identified potential therapeutic targets for future intervention against yolk sac vasculopathy, birth defects, and other complications associated with diabetic pregnancies.

The clinical implications of placental diagnoses

The clinical utility of placental pathology is both overestimated and underestimated, and the overall quality of placental pathology reporting, even at major medical centers, is highly variable. Clear benefits of examining placentas include the immediate diagnosis of treatable conditions in both the mother and the infant, clarification of the underlying etiology of adverse pregnancy outcomes, estimation of recurrence risk, and guidance for the management of future pregnancies. In order to realize these benefits and get the most out of their pathology departments, it is critical for clinicians to understand the range and implications of placental lesions. This article will review the nomenclature, diagnostic criteria and pitfalls, and clinical significance of seven common placental disease processes and a handful of other lesions.