Background: Traditionally, 2D ultrasound have been used for the diagnosis of a suspected morbidly adherent placenta previa. Recently, 3D power Doppler technique was introduced to diagnose morbidly adherent placenta (MAP).
Aim: The study objective was to assess the accuracy of prenatal 3-dimensional power Doppler analysis of vascular and flow placental indices to predict the morbidly adherent placenta objectively.
Materials and Methods: A prospective study executed among women with placenta previa between 28 and 32 weeks of gestation. Patients were examined by 2D ultrasounds which was used in management decisions. 3D Power Doppler vascular, flow and vascular flow indices were measured during the same examination after tracing of maximum placental thickness; data were blinded to obstetricians. Histopathology was used to confirm MAP. Severe morbidly adherent placenta was described as increta/percreta on histopathology, blood loss >2L, and >2 units of PRBC transfused. Sensitivities, specificities, predictive values, and likelihood ratios were calculated.
Results: Our results showed that the 3D Doppler VI ≥ 16 predicted MAP with a 100% sensitivity ,100% specificity which are better than those of 2D ultrasound (60.0% and 89.1% respectively).
Sever MAP occurred in 51.2% of MAP and 3D Doppler of VI > 33.1 predicted sever MAP with a sensitivity of 73.9% and specificity of 86.4%, which was superior to 2D ultrasound.
Conclusion: In placenta previa patients, the vascular index accurately predicts the morbidly adherent placenta. Furthermore, vascular and vascular flow indices of 3D power Doppler were more predictive of severe cases of morbidly adherent placenta compared to 2D ultrasound.