Superb micro-vascular imaging of placental microcirculation in pregnant women with preeclampsia

Abstract Background: The purpose of this study was to explore the association of placental microcirculation with the risk of preeclampsia using superb micro-vascular imaging (SMI). Methods: A case-control study was conducted in 2017 with 38 healthy pregnant women and 37 women with preeclampsia from the Department of Obstetrics and Gynaecology of Hebei General Hospital. The vessel counts per unit area (n/cm 2 ) and the hemodynamic parameters of the central part of the placenta microartery, including the pulsatility index (PI) and resistance index (RI), peak systolic velocity and diastolic velocity ratio (S/D), and time average velocity (TAV), were evaluated using superb micro-vascular imaging (SMI). The expression of CD34 in the placental tissue and the microvessel density were also calculated. Results: The mean ages of women in the case and control groups were 31.43 and 31.24 years, respectively. Crude analyses indicated that women with preeclampsia were associated with a lower TAV (p<0.001) and vessel counts per unit area (p<0.001), whereas no significant differences were found between groups for PI (p=0.849), RI (p=0.069), and S/D (p=0.129) under SMI. Multiple logistic regression analysis indicated that RI (OR: 309.94; 95%CI: 2.97-32369.62; p=0.016), TAV (OR: 0.51; 95%CI: 0.36-0.71; p<0.001), and vessel counts per unit area (OR: 0.01; 95%CI: 0.00-0.86; p=0.042) under SMI were associated with the risk of preeclampsia, whereas PI (OR: 0.05; 95%CI: 0.00-1.34; p=0.074) and S/D (OR: 1.08; 95%CI: 0.39-2.96; p=0.885) under SMI were not associated with the risk of preeclampsia. Finally, the microvessel density of placental tissue in the preeclampsia group was significantly lower than that in the control group (p<0.001). Conclusions: The findings of this study indicate that RI, TAV, and vessel counts per unit area under SMI could reflect placental microcirculation in pregnant women with preeclampsia.