Three-dimensional power Doppler placental vascularisation indices in early pregnancy: a pilot study

The objective of our study was to assess 1st trimester placental vascularisation using three-dimensional (3D) power Doppler vascular indices. A cross-sectional study was used involving 41 normal pregnancies from 7 to 10 + 6 weeks. Placental volume was obtained using the 30° virtual organ computer-aided analysis (VOCAL) method. The mean, median, standard deviation (SD), minimum and maximum values were calculated for three vascular indices: the VI, vascularisation index; the FI, flow index and the VFI, vascularisation and flow index. Pearson's correlation coefficient (r) was used to assess the correlation between vascular indices and crown-rump length (CRL). Our results showed mean (± SD) values ranged from 8.66 ± 12.04 to 15.34 ± 13.89 for the VI, from 63.83 ± 43.61 to 109.22 ± 33.87 for the FI and from 9.52 ± 13.86 to 20.59 ± 22.97 for the VFI. There was no correlation between CRL and VI (r = 0.073, p = 0.630) nor VFI (r = 0.147 and p = 0.037); there was a weak correlation between CRL and FI (r = 0.332, p = 0.037). It was concluded that the FI was the only 3D power Doppler vascular index that was correlated with CRL between 7 and 10 + 6 weeks' gestation.