The assessment of placental volume and mean gray value in preeclamptic placentas by using three-dimensional ultrasonography

Objectives: We aimed to evaluate the placental volume and placental mean gray value in preeclampsia and healthy placentas by using three-dimensional (3D) ultrasonography and Virtual Organ Computer-aided AnaLysis (VOCAL).

Methods: This case-control prospective study consisted of 27 singleton pregnancies complicated by preeclampsia and 54 healthy singleton pregnancies matched for gestational age, maternal age and parity. Placental volume and placental volumetric mean gray values were evaluated. The placental volume (cm(3)) was analyzed using the VOCAL imaging program, and 3D histogram was used to calculate the volumetric mean gray value (%).

Results: Preeclamptic and control group consisted of 27 (mean age: 28.90 ± 5.95 years, mean gestation: 32.0 ± 4.55 weeks) and 54 (mean age: 29.48 ± 5.78 years, mean gestation: 32.61 ± 4.23 weeks) singleton pregnancies, respectively. Placental volume was significantly smaller in preeclampsia (250.62 ± 91.69 versus 370.98 ± 167.82 cm(3); p = 0.001). Volumetric mean gray value of the placenta was significantly higher in preeclampsia (38.24 ± 8.41 versus 33.50 ± 8.90%; p = 0.043). Placental volume was significantly correlated with the estimated fetal weight (r = 0.319; p = 0.003). There was negative significant relation between placental volume and umbilical artery pulsatility index, resistance index and systolic/diastolic ratio (r = -0.244, p = 0.024; r = -0.283, p = 0.005; r = -0.241, p = 0.024, respectively).

Conclusions: Placental volume diminishes significantly in preeclampsia, whereas volumetric mean gray values increases. This may reflect the early alterations in preeclamptic placentas, which may help to understand the pathophysiology better.