Viscoelasticity quantification by ultrasound for placental assessment in healthy versus gestational diabetes mellitus pregnancies.

INTRODUCTION

Viscosity is a novel parameter, recently introduced in the use of elastographic techniques. Ultrasound viscoelastic imaging quantifies tissue stiffness and viscosity. This study investigated its application for quantitatively assessing placental viscoelastic parameters and identifying functional alterations in healthy versus gestational diabetes mellitus (GDM) pregnancies.

METHODS

Pregnant women undergoing mid-trimester checkups (Jan-Apr 2025) at Zhongda Hospital were prospectively enrolled. Based on Oral Glucose Tolerance Test (OGTT) results, participants were categorized into GDM and control groups. Vmean and Emean were measured in the middle of anterior placenta using Mindray Resona A20S. Inter- and intra-observer reproducibility was assessed on the initial 55 placentas. Variables influencing Vmean were analyzed using univariate and multivariate linear regression.

RESULTS

Reproducibility was excellent for Vmean (intra-observer ICC = 0.95, 95 % CI:0.91-0.97; inter-observer ICC = 0.94, 95 % CI:0.89-0.96) and good for Emean (intra-observer ICC = 0.79, 95 %CI:0.64-0.88; inter-observer ICC = 0.75, 95 % CI:0.58-0.86). The GDM group had significantly higher BMI, abdominal subcutaneous adipose tissue thickness (ASAT-thickness), Vmean, and Emean than controls (all p < 0.05). Multivariate regression identified GDM (β = 0.346, p < 0.001), Emean (β = 0.136, p < 0.001), and ASAT-thickness (β = 0.222, p < 0.001) as independent positive correlates of Vmean. This association between GDM and elevated Vmean was consistent across different levels of maternal ASAT-thickness.

CONCLUSIONS

Ultrasound viscoelastic imaging has demonstrated good reproducibility for measurements of placental Vmean and Emean. Elevated Vmean in pregnancies with GDM, along with its independent associations with GDM status, placental stiffness (Emean), and ASAT-thickness, supports its utility as a diagnostic parameter for placental assessment in GDM. The consistent association between GDM and elevated Vmean across different levels of maternal ASAT-thickness further strengthens its potential clinical applicability.