Placental vascularization measured by three-dimensional power Doppler ultrasound at 11 to 13+6 weeks' gestation in normal and aneuploid fetuses

Objective To establish the: potential role of three-dimensional (3D) power Doppler evaluation of the placental circulation in aneuploidy screening at 11 to 13 + 6 weeks of gestation. Methods 3D power Doppler ultrasound examination of the placenta was performed in 25 pregnancies with fetuses with abnormal karyotype and in 100 control pregnancies at 11 to 13 + 6 weeks of gestation. Using the same pre-established settings for all cases, the vascularization index (VI), flow index (FI) and vascularization flow index (VFI) were calculated for the whole placenta. Results In the cbromosomally normal group all the vascular indices increased significantly with advancing gestation between 11 and 13 + 6 weeks (VI: r = 0.482, P < 0.001; FI: r = 0.295, P = 0.0029; VFI, r = 0.484, P < 0.001). In the chromosomally abnormal group, the flow indices were not significantly different from normal in cases with trisomy 21 (13 cases), but they were significantly reduced compared with normal in cases with trisomies 13 and 18 (VI: t = 8.321, P < 0.0001: FI: t = 12.934, P < 0.0001; VFI: t = 7.608, P < 0.0001). Conclusions 3D power Doppler evaluation of the placental circulation is not useful in screening for trisomy 21, and unlikely to furtber increase the already high detection rate for trisomies 13 and 18. However, we provide normal ranges of placental vascular indices between 11 + 0 and 13 + 6 weeks of gestation, which may be useful in future research on placental vascularity in certain at-risk pregnancies. Copyright (c) 2007 ISUOG. Published by John Wiley & Sons, Ltd.