The subplacental complex: further sonographic observations

The subplacental complex, which represents vascular channels at the placental-myometrial junction, is a structure that is routinely seen sonographically in patients with posteriorly placed placentas, but not in those with anteriorly placed placentas. This study shows that the subplacental complex is a constant anatomic feature of the placenta regardless of whether it develops on the anterior or posterior uterine wall, and can be visualized in most patients if the subplacental complex is in the focal plane of the transducer. This has important implications in patients with anterior placentas that are being evaluated for abruption or in patients in whom fetal parts lie just beneath the anterior myometrial wall.