Clinical significance of three-dimensional power Doppler combined with two-dimensional Doppler ultrasonography for evaluating fetal growth restriction.

OBJECTIVES

To assess the predictive accuracy of three-dimensional (3D) power Doppler combined with two-dimensional (2D) Doppler ultrasonography in detecting fetal growth restriction (FGR).

METHODS

The study was conducted on singleton pregnancies presenting for growth ultrasound examinations between 20 and 40 weeks of gestation. 63 patients with FGR were enrolled and matched 1:1.8 for gestational age with normal fetuses. Both groups were further divided into subgroups, with 32 weeks as the threshold-early-onset and late-onset FGR groups, and corresponding control groups. Conventional 2D Doppler parameters and standardized 3D power Doppler measurements of the placenta, including vascularization index (VI), flow index (FI), and vascularization-flow index (VFI) were obtained for each patient.

RESULTS

(1) The average gestational weeks of delivery and birth weight of newborns in early-onset and late-onset FGR case groups were lower than those in control groups, while the incidence of placenta previa and adverse pregnancy outcomes were higher than those in control groups. (2) The biparietal diameter, head circumference, abdominal circumference, femur length, estimated fetal weight, middle cerebral artery systolic/diastolic velocity ratio (S/D), pulsatility index (PI), resistance index (RI), and placental blood perfusion indices of vascular index (VI), flow index (FI), vascular flow index (VFI), and cerebro-placental ratio (CPR) of the early-onset and late-onset FGR case groups were all lower than those of the control group. Moreover, the S/D, PI, and RI of the umbilical and uterine arteries were higher than those of the corresponding control group. (3) For early-onset FGR, the area under the curve (AUC) of the umbilical artery PI was the largest (0.861), exhibiting the highest predictive value. When combined with the placental blood perfusion index, the AUC was 0.789. For late-onset FGR, the AUC of the CPR was 0.861. After integrating the placental blood perfusion index, the AUC increased to 0.877. The positive likelihood ratio (PLR) of combined 2D Doppler indexes (21.938) and negative likelihood ratio (NLR) of VFI (0.565) were the highest in the early-onset FGR group. The PLR of combined 3D Doppler indexes (8.536) and NLR of VFI (0.557) were the highest in the late-onset FGR group.

CONCLUSIONS

The combination of 3D Doppler indices with 2D Doppler ultrasonography demonstrated superior predictive value in diagnosing late-onset FGR compared to other conventional indicators. The 3D Dower index, VFI, has a good true-negative predictive value for both early- and late-onset FGR.