Three‐dimensional <scp>Doppler</scp> ultrasound assessment of multiple vessels in vasa previa

Vasa previa (VP) occurs in approximately 1 in 1200–2500 births1. VP is characterized by fetal blood vessels traversing the fetal membranes near the internal cervical os without protection from Wharton's jelly or placental tissue, creating a high risk of catastrophic fetal hemorrhage during labor or rupture of membranes. Accurate prenatal diagnosis of VP using transvaginal ultrasound (TVS) with color Doppler is critical to prevent these adverse outcomes, as it enables prelabor Cesarean delivery and significantly improves neonatal survival2, 3. However, conventional two-dimensional (2D) ultrasound may fail to identify additional aberrant vessels4. Three-dimensional (3D) ultrasound imaging has emerged as a valuable adjunct by offering superior spatial detail and anatomical mapping of all vessels crossing the internal cervical os5, 6. This work was carried out at Lis Maternity and Women's Hospital, Tel Aviv, Israel, and approved by the Tel Aviv Sourasky Medical Center Institutional Review Board. For all cases in the series we used standard 2D-TVS combined with color Doppler as the initial screening modality at around 22 weeks' gestation. Cases with at least one fetal vessel crossing the internal cervical os underwent further dedicated 3D Doppler imaging, employing multiplanar reconstruction and surface-rendering techniques to achieve comprehensive visualization of fetal vessels. All examinations were performed using a Voluson E10 or Expert 22 device (GE Healthcare, Zipf, Austria) equipped with a 5–9-MHz transvaginal transducer. Postnatal placental examination confirmed all prenatal findings. All three cases of multiple-vessel VP involved a bilobed placenta. While 2D ultrasound initially identified a single aberrant vessel in each case (Figure 1), 3D Doppler imaging subsequently demonstrated two crossing vessels in two cases (Cases 1 and 3) and three crossing vessels in one case (Case 2), along with velamentous insertion and additional velamentous vessels (Figure 2). The detailed vascular mapping significantly influenced clinical counseling and management decisions. Following the standard protocol at our institution, patients were admitted for inpatient monitoring at 34 weeks' gestation, with elective Cesarean delivery scheduled at 36 weeks7. All deliveries proceeded without complications. Placental examination after delivery validated the presence of multiple vessels, matching precisely the prenatal 3D ultrasound images. Neonatal outcomes were optimal, with no cases of hemorrhage and no transfusion requirements. Intrauterine interventions, such as fetoscopic laser ablation, have been explored in selected cases of VP to reduce the risk of fetal hemorrhage8. Accurate identification and detailed anatomical mapping of all aberrant fetal vessels are paramount for the safe execution of these procedures. Demonstrating multiple crossing vessels prenatally using 3D Doppler ultrasound could therefore be critically important, as missing additional vessels could lead to incomplete treatment, continued risk of fetal hemorrhage or inadvertent injury during intervention. Our findings highlight the significant added value of 3D Doppler ultrasound in diagnosing complex VP cases involving multiple fetal vessels. Previous studies established the clinical benefits of prenatal VP diagnosis and have acknowledged the limitations of 2D sagittal ultrasound imaging in detecting lateral or oblique vessels crossing the internal cervical os9. By contrast, the application of advanced imaging techniques, including 3D and four-dimensional ultrasound methods, enables multiplanar reconstruction and surface rendering that provide full visualization of the vascular anatomy, reducing the risk of partial or missed diagnosis4, 5. This case series suggests that multiple vessels crossing the internal cervical os may be underrecognized on 2D ultrasound and expands current knowledge by explicitly demonstrating the role of 3D ultrasound and its value for accurate clinical planning and management. In conclusion, our series strongly supports incorporating routine 3D ultrasound if VP is suspected. This approach enables thorough vascular mapping, enhances prenatal management, optimizes delivery timing and ultimately improves neonatal outcomes. The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.