H. S. Wong

Evaluation of sonographic diagnostic criteria for placenta accreta

To compare the diagnostic value of reported sonographic criteria for placenta accreta and to develop a composite score system for antenatal evaluation.

Antenatal diagnosis of non‐previa placenta increta with histological confirmation

A 36-year-old woman, gravida 4 para 3, was referred to our unit at 20 weeks’ gestation because of a complicated obstetric history. She had had three previous vaginal deliveries, all of which had been associated with primary postpartum hemorrhage. In the second and third deliveries, the placenta was noted to be adherent at the third stage of labor. Manual removal of the placenta resulted in profuse hemorrhage, requiring massive blood transfusion and intensive care admission. In the third pregnancy, partial/focal placenta accreta was confirmed on histopathological examination of the placenta. On ultrasound examination in the current pregnancy (ATL HDI 5000, Philips, Bothell, WA, USA), the placenta was noted to be bilobed, with one lobe located posteriorly and the other anteriorly, and with the cord insertion between the lobes. Placental lacunae were not seen in the anterior lobe. However, tongues of placental tissue could be seen interrupting the placental–uterine wall interface in the anterior, lateral and posterior walls of the uterus (Figures 1 and 2a). Communicating vessels were seen running directly between the placental substance and the uterine musculature at these interface-interruption sites on Doppler examination of both posterior (Figure 2a) and anterior (Figure 2b) walls. Placenta increta was diagnosed. Since the couple had completed their family, an elective Cesarean hysterectomy was planned and this was performed uneventfully at 37 weeks’ gestation. The placenta was bilobed and adherent to the uterine wall both anteriorly and posteriorly, with histological evidence of increta. Abnormal placentation varies in the degree of myometrial invasion from placenta accreta, to increta and percreta. Detection rates recorded in the literature of antenatal sonographic detection of placenta accreta vary, ranging from 33% (4/12)1 to 100% (5/5)2. The diagnostic criteria suggested in the literature for the sonographic diagnosis of placenta accreta, increta or percreta include loss of hypoechoic retroplacental myometrial zone, presence Figure 1 On gray-scale ultrasound, the placental–uterine wall interface is interrupted by tongues (arrows) of placental (PL) tissue in the anterior (a) and lateral (b) uterine (UT) walls. L, left; LAT, lateral.

Specific sonographic features of placenta accreta: tissue interface disruption on gray‐scale imaging and evidence of vessels crossing interface‐ disruption sites on Doppler imaging

The antenatal detection rate of placenta accreta (a collective term for accreta, increta and percreta) on ultrasound varies in the literature, ranging from 33% (4/12)1 to 100% (5/5)2. Similarly, the gray-scale sonographic diagnostic criteria are diverse (placental lacunae, absence of the retroplacental clear zone and interruption of posterior bladder wall–uterine interface), with the sensitivity of individual criteria ranging from 7% to 93%3. With the use of color and/or power Doppler, the reported sensitivity and specificity of antenatal diagnosis increase to 82.4–100% and 92–96.8%, respectively2,4,5. We have reported the sonographic signs of tissue interface disruption on gray-scale imaging and those of vessels crossing interface-disruption sites on Doppler imaging6 (Figure 1). These signs correspond with the histological findings of placenta accreta. In this retrospective analysis, we examined the performance of these signs in the diagnosis of placenta accreta. From our departmental ultrasound database, 41 patients were identified who had been referred for the exclusion of placenta accreta in 2004–2005. Five patients were lost to follow-up and were excluded from the analysis. Gray-scale imaging was performed in all of the remaining 36 patients and Doppler (color and/or power) was perfomed in 30, using ATL HDI 5000 or iU22 ultrasound machines (Philips, Bothell, WA, USA). Doppler was not performed if on gray-scale imaging there was clear

A Case of Thanatophoric Dysplasia : The Early Prenatal 2D and 3D Sonographic Findings and Molecular Confirmation of Diagnosis

Objective: To present the early 2D and 3D ultrasound findings and the molecular confirmation in a case of thanatophoric dysplasia. Methods: On ultrasound examination, there was frontal bossing, increased nuchal translucency and short limbs at 12 weeks’ gestation and a small thorax and short and bowed long bones on 3D at 16 weeks. Amniocentesis and DNA analysis confirmed the mutation of FGFR3 gene indicating thanatophoric dysplasia. Results: After medical termination of pregnancy, the postmortem X-ray and pathology examination findings were consistent with the diagnosis. Conclusion: 3D anatomy scan and molecular confirmation may be helpful in early diagnosis and genetic counseling of thanatophoric dysplasia.

Examination of the secondary palate on stored 3D ultrasound volumes of the fetal face

To examine the use of oblique planes from stored three‐dimensional (3D) ultrasound volumes of the fetal face for viewing the secondary palate at various gestational ages.

Antenatal diagnosis of anophthalmia by three-dimensional ultrasound: a novel application of the reverse face view

The prenatal diagnosis of anophthalmia can be made on the demonstration of absent eye globe and lens on the affected side(s) on two‐dimensional ultrasound examination, but when the fetal head position is unfavorable three‐dimensional (3D) ultrasound may reveal additional diagnostic sonographic features, including sunken eyelids and small or hypoplastic orbit on the affected side(s). We present two cases of isolated anophthalmia diagnosed on prenatal ultrasound examination in which 3D ultrasound provided additional diagnostic information. The reverse face view provides valuable information about the orbits and the eyeballs for prenatal diagnosis and assessment of anophthalmia. Copyright

Sonographic study of the decidua basalis in early pregnancy loss.

To describe the sonographic findings in the decidua basalis layer in spontaneous early pregnancy loss and to compare them with those in normal pregnancy.

Viewing of the Soft and the Hard Palate on Routine 3-D Ultrasound Sweep of the Fetal Face – A Feasibility Study

Objectives: To report a technique to view the fetal soft and hard palates, utilizing acquired routine 3-D volumes of the fetal face. Method: The axial, sagittal and coronal planes in acquired volumes of 3-D surface rendering of 5 normal fetal faces obtained at 19, 21, 23, 26 and 28 weeks, respectively, were reviewed by focusing on the uvula. Results: The surfaces of the soft and the hard palate could be viewed in oblique axial, oblique sagittal and targeted coronal planes in all fetuses. Conclusion: Rotating or tilting of the axial, sagittal and coronal planes of the fetal head allows the visualization of the various aspects of the soft and hard palates, with the uvula as a useful landmark.

Antenatal topographical assessment of placenta accreta with ultrasound.

The major risk of placenta accreta is severe haemorrhage when the placenta is separated at delivery. A case series of placenta accreta with antenatal sonographic topographical assessment of myometrial involvement is presented. The extent of myometrial involvement and the vascularity could be assessed by the observation of the extent of placental–uterine wall interface disruption and the vessels crossing the interface disruption sites. Such assessment results in strategic planning of management of the placenta at delivery with favourable pregnancy outcomes.

The use of ultrasound in assessing the extent of myometrial involvement in partial placenta accreta

The continued presence of abundant maternal vascularization of the retained placenta (depicted by angiography and color Doppler imaging) despite decreasing serum βhCG levels, as in the present case, has been reported previously7. The continued vascularization, previously associated with failure of conservative treatment of placenta previa percreta, led us to perform multiple bilateral uterine artery embolization procedures during the postoperative course in the current case. A systematic English language literature search (PubMed and Medline) between 1966 and 2007 using the search terms ‘placenta previa’, ‘placenta percreta’, ‘previa percreta’, ‘uterine artery embolization’, ‘conservative management’ and ‘methotrexate’ has confirmed that this is the first report of multiple bilateral uterine artery embolizations in the conservative management of a patient with placenta previa percreta. This case suggests that multiple postoperative bilateral uterine artery embolizations may increase the success of conservative management of patients with this life-threatening condition.