HDlive imaging of circumvallate placenta

Abstract

Circumvallate placenta is a morphological placental abnormality in which the chorionic plate is smaller than the basal plate, resulting in the folding back of placental and fetal membranes towards the chorionic surface. There have been numerous reports on the antenatal diagnosis of circumvallate placenta using two-dimensional (2D) and three-dimensional ultrasound1-4, however, to the best of our knowledge, this is the first to present HDlive and HDlive silhouette mode imaging for the prenatal diagnosis of a circumvallate placenta. A 26-year-old pregnant Japanese primigravida was referred to our hospital at 14 + 5 weeks' gestation because of a suspected placental tumor. 2D sonography (Voluson E8, GE Healthcare Ultrasound, Milwaukee, WI, USA) showed a single live fetus with biometry consistent with gestational age. Placental examination revealed an increased thickness (29 mm) with irregular anechoic areas on the periphery of the fetal surface. Subsequent color Doppler showed no blood flow within these areas. HDlive mode revealed a slightly curved placental edge with the umbilical cord attached at the center of the placenta and demonstrated an elevated lobule located at the center of the placenta. At 16 + 5 weeks' gestation, HDlive mode depicted clearly a central depression in the placenta with thick edges folded upon themselves, forming rolled-up placental margins (Figure 1). Two weeks later, follow-up ultrasound with HDlive mode revealed the umbilical cord attached to the central depressed area of the placenta, which was surrounded by thick, scalloped placental edges (Figure 2a). HDlive silhouette mode (Voluson E10, GE Healthcare Ultrasound) depicted the thickened, curved edges of the placenta and the central depressed region to which the umbilical cord was attached. Chorionic surface vessels were seen branching out from the umbilical cord over the fetal surface of the placenta to form the villous tree (Figure 2b). Fetal growth was normal and no fetal anomalies were detected during pregnancy. At 38 + 3 weeks' gestation, Cesarean section was performed due to non-reassuring fetal heart rate patterns, and a 2834-g female, 49 cm in length, was delivered. Apgar scores were 8 at 1 min and 9 at 5 min and umbilical artery pH was 7.27. Placental examination revealed a weight of 580 g and confirmed a typical circumvallate placenta (Figure 3), with true knot formation. In the present case, circumvallate placenta was suspected correctly on early mid-trimester 2D ultrasound examination. HDlive imaging demonstrated clearly a central depression of the placenta surrounded by thick, rolled-up placental margins, and attachment of the umbilical cord to the central depressed region, confirming the diagnosis of a circumvallate placenta. The clear image obtained by HDlive mode is due to its ability to increase depth perception through the creation of light and shadow effects from an adjustable light source5. HDlive silhouette mode demonstrated the placental margins and the depressed placental center clearly. Moreover, chorionic surface vessels were seen branching out from the umbilical cord over the fetal surface of the placenta to form the villous tree. These techniques depicted the shape of the circumvallate placenta as it is seen on postpartum imaging and thus appear to be useful adjuncts to 2D sonography for the diagnosis of placental abnormalities.