Objectives: To use shear wave elastography (SWE) to longitudinally evaluate placental
elasticity in normal human pregnancy, and to develop reference ranges for its use
at various gestational ages throughout pregnancy.
Materials & Methods: Data was obtained from a prospective cohort within the Human
Placenta Project, involving 90 pregnant participants with uncomplicated singleton
gestations. Placental elasticity was measured using SWE at eight distinct gestational
time points, from 12 to 37 weeks. Descriptive statistics were reported as median and
interquartile for continuous variables, and number and percentage of the total for
categorical variables. Distribution of response variables (Elastography) were assessed
with QQ-plots, skewness and kurtosis values. Candidate models were compared with likelihood
ratio tests.
Results: Out of the 610 pregnant participants initially enrolled, 90 met the criteria
for the reference population. Mean SWE values showed a steady increase with advancing
gestational age, from 1.283 meters per second (m/s) at 12–13 weeks to 1.381 m/s at
36–37 weeks. Similarly, Young’s modulus values increased from 4.99 kPA to 5.59 kPA
across the same interval. SWE values were consistent across different placental regions
and showed a continuous upward trend with gestational age. Gestational age was significantly
associated with SWE values in the central placenta, with fitted reference ranges provided.
Conclusion: SWE is a feasible and reproducible tool for assessing placental stiffness
throughout gestation.
