Vasa previa: prenatal detection by three-dimensional ultrasonography.
OBJECTIVE
To describe three-dimensional (3D) ultrasonography (US) for the antepartum diagnosis of vasa previa.


METHODS
This was a descriptive study of two pregnant women who were suspected to have vasa previa by conventional gray-scale ultrasonography. Three-dimensional studies were also performed during the early third trimester to further investigate the possibility of this condition.


RESULTS
In the first case, 3D US provided gray-scale multiplanar and surface-rendered views of an aberrant vessel over the internal cervical os. For the second case, a 'flight-path' technique allowed the examiner to follow axial views of the endocervical canal toward the internal os until an aberrant vessel was verified. The 'niche-mode' analysis, with and without color power Doppler ultrasonography, was also used to confirm the diagnosis.


CONCLUSIONS
Three-dimensional ultrasonography offers several additional imaging tools that are not currently provided by more conventional ultrasonography for the detection of vasa previa. It represents an important adjunct to two-dimensional (2D) studies, especially when this diagnosis is questionable.
Lee
W
W
Division of Fetal Imaging, Department of Obstetrics and Gynecology, William Beaumont Hospital, 3601 West Thirteen Mile Road, Royal Oak, MI 48073-6769, USA.
Kirk
J S
JS
Comstock
C H
CH
Romero
R
R
D000328:Adult; D005260:Female; D005333:Fetus / Q000098:blood supply*; D006801:Humans; D010920:Placenta / Q000098:blood supply*; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000000981:diagnostic imaging*; D011263:Pregnancy Trimester, Third; D018615:Ultrasonography, Doppler, Color / Q000379:methods*; D016216:Ultrasonography, Prenatal / Q000379:methods*; D014621:Vagina