In vivo assessment of placental elasticity in intrauterine growth restriction by shear-wave elastography.

PURPOSE: In this study, we evaluated the placental elasticity in vivo by shear-wave elastography in pregnant women under follow-up for intrauterine growth restriction (IUGR) and compared the elasticity values to normal pregnancies.

MATERIAL AND METHODS: This prospective study included 42 pregnant women with a possible diagnosis of intrauterine growth restriction based on obstetrical grayscale and Doppler ultrasonography and 42 women with a normal pregnancy during the 2nd and 3rd trimester. During follow-up examinations, seven fetuses showed an increased growth and were delivered with a birth-weight above the 10 percentile. However, for statistical purposes we included these seven patients in the IUGR group due to prospective nature of the study. All patients initially underwent obstetrical grayscale and Doppler ultrasonography with measurement of resistivity and pulsatility indices from uterine arteries. Subsequently, elasticity values of the peripheral and central part of the placentas from fetal and maternal surfaces were measured by shear-wave elastography. Following delivery, Apgar scores at 1st and 5th minute, birth weight were collected. For statistical analysis, Mann-Whitney U test was used. ROC curves were plotted and cut-off values for elasticity values were analyzed.

RESULTS: Median elasticity values of the central part of the placentas from maternal (28kPa vs 6kPa) and fetal sides (21.5kPa vs 5kPa) were significantly higher in IUGR pregnancies compared to the control group (p<0.001). Similarly, median elasticity values of peripheral part of placentas from maternal (22kPa vs 5.35kPa) and fetal sides (22.5kPa vs 5.3kPa) were significantly higher in IUGR pregnancies compared to the control group (p<0.001).

CONCLUSION: Placental stiffness values are significantly higher in patients with IUGR. Shear-wave elastography can be used as a non-invasive, complementary method to gray-scale and Doppler ultrasound for diagnosing IUGR.