The role of shear wave elastography in the assessment of placentas in healthy pregnancy women during third-trimester: A preliminary study

Assessing Placental Shear Wave Elastography as a Tool for Evaluating Preeclampsia

Background Hypertensive disorders of pregnancy, especially its dreaded complication preeclampsia, remain a major cause of morbidity and mortality for both the mother and the fetus. Existing tools for the prediction of preeclampsia remain inadequate in their sensitivity and specificity. Hence, there is an urgent need for a reliable, economically feasible, and objective marker for its diagnosis/early prediction. In this regard, shear wave elastography has shown great promise. Shear wave elastography is a novel method to quantify tissue stiffness, which is objective and has significantly lower inter-observer variability. Objectives We aim to quantify the tissue elasticity using point shear wave elastography (pSWE) in the placentas of diagnosed cases of preeclampsia and to compare them with the placentas of healthy controls in order to evaluate if there is a significant statistical difference between the two. Materials and methods This comparative study was conducted at the Department of Radiodiagnosis, Dr. D. Y. Patil Medical College, Hospital and Research Centre, Pune, India, from August 2022 to July 2024. The study included 60 participants, divided into two groups: 30 patients with preeclampsia and 30 healthy pregnancies. Placental stiffness was measured using a Samsung HS70A ultrasound machine (Samsung Electronics Pvt. Ltd., Seoul, South Korea), and pSWE was performed with a curvilinear probe. Data was analyzed using IBM SPSS Statistics for Windows, Version 21 (Released 2012; IBM Corp., Armonk, New York, United States), and the significance of differences between the two groups was assessed using an independent t-test with a p-value of <0.05, considered statistically significant. Results The mean placental stiffness, measured in kilopascals (kPa), was significantly higher in the preeclampsia group (11.71 ± 1.52 kPa) in comparison to the healthy group (3.36 ± 0.66 kPa) (p = 0.001). Patients suffering from preeclampsia were found to have significantly higher levels of placental stiffness. Conclusion Early diagnosis remains key to managing preeclampsia so that adequate monitoring and treatment could be provided to the patients. Our study showed that there is a significant statistical difference in the placental stiffness in patients with preeclampsia in comparison to a healthy placenta. Hence, shear wave elastography can be used as a supplementary tool to aid in the diagnosis/prediction of preeclampsia.

The Relationship between Placental Shear Wave Elastography and Fetal Weight-A Prospective Study

Background/Objectives: The utility of shear wave elastography (SWE) as an adjunct to ultrasound biometry and Doppler velocimetry for the examination of placental dysfunction and suboptimal fetal growth is unclear. To date, limited data exist correlating the mechanical properties of placentae with fetal growth. This study aimed to investigate the relationship between placental shear wave velocity (SWV) and ultrasound estimated fetal weight (EFW), and to ascertain if placental SWV is a suitable proxy measure of placental function in the surveillance of small-for-gestational-age (SGA) pregnancies. Methods: This prospective, observational cohort study compared the difference in placental SWV between SGA and appropriate-for-gestational-age (AGA) pregnancies. There were 221 women with singleton pregnancies in the study cohort-136 (61.5%) AGA and 85 (38.5%) SGA. Fetal biometry, Doppler velocimetry, the deepest vertical pocket of amniotic fluid, and mean SWV were measured at 2-4-weekly intervals from recruitment to birth. Results: There was no difference in mean placental SWV in SGA pregnancies compared to AGA pregnancies, nor was there any relationship to EFW. Conclusions: Although other studies have shown some correlation between increased placental stiffness and SGA pregnancies, our investigation did not support this. The mechanical properties of placental tissue in SGA pregnancies do not result in placental SWVs that are apparently different from those of AGA controls. As this study did not differentiate between constitutionally or pathologically small fetuses, further studies in growth-restricted cohorts would be of benefit.

Shear wave velocity measurement of the placenta is not limited by placental location

INTRODUCTION

Ultrasound elastography shows diagnostic promise via the non-invasive determination of placental elastic properties. A limitation is a potential for inadequate measurements from posterior placentae. This study aimed to analyse placental position's influence on measures of shear wave elastography (SWV).

METHODS

SWV elastography measurements were obtained via ultrasound at 24, 28 and 36 weeks gestation from 238 pregnancies. . The placental position was labelled as either anterior, posterior or fundal/lateral. Average SWV measurements (m/s) and the corresponding standard deviations (SD) were used for data analysis.

RESULTS

There was a statistically significant difference between SWV recorded from anterior (1.33 ± 0.19)m/s and posterior (1.39 ± 0.18)m/s placentae (p < 0.001). However, the average sampling depth between these groups was significantly different (3.98 cm vs. 5.38 cm, p < 0.001). There was no statistically significant difference between SWV when measurements were compared at similar depths, regardless of placental location. The addition of placental position to a previously developed mixed-effects model confirmed placental position did not result in improved SWV measurements. In this model, sampling depth remained the best predictor for SWV.

CONCLUSIONS

This study showed that placental position does not influence the accuracy or reliability of SWV.

Engineered models for placental toxicology: Emerging approaches based on tissue decellularization

Recent increases in prescriptions and illegal drug use as well as exposure to environmental contaminants during pregnancy have highlighted the critical importance of placental toxicology in understanding and identifying risks to both mother and fetus. Although advantageous for basic science, current in vitro models often fail to capture the complexity of placental response, likely due to their inability to recreate and monitor aspects of the microenvironment including physical properties, mechanical forces and stiffness, protein composition, cell-cell interactions, soluble and physicochemical factors, and other exogenous cues. Tissue engineering holds great promise in addressing these challenges and provides an avenue to better understand basic biology, effects of toxic compounds and potential therapeutics. The key to success lies in effectively recreating the microenvironment. One strategy to do this would be to recreate individual components and then combine them. However, this becomes challenging due to variables present according to conditions such as tissue location, age, health status and lifestyle. The extracellular matrix (ECM) is known to influence cellular fate by working as a storage of factors. Decellularized ECM (dECM) is a recent tool that allows usage of the original ECM in a refurbished form, providing a relatively reliable representation of the microenvironment. This review focuses on using dECM in modified forms such as whole organs, scaffold sheets, electrospun nanofibers, hydrogels, 3D printing, and combinations as building blocks to recreate aspects of the microenvironment to address general tissue engineering and toxicology challenges, thus illustrating their potential as tools for future placental toxicology studies.