Placenta accreta. Additional sonographic observations

Abstract

Recent reports describe the antenatal sonographic diagnosis of placenta accreta based on failure to visualize a hypoechoic zone at the placental margin. This finding was confirmed in our series of seven cases. New observations in this series include prominent large or multiple placental venous lakes and periuterine vascularity in six of seven cases, and progressive thinning and disappearance of the retroplacental hypoechoic zone on sequential examinations in two of seven cases. Loss of normal venous flow pattern on Doppler interrogation of the peripheral placental margin also appeared to be of value in two patients. Histologic correlates for these findings are suggested on the basis of the primary histopathologic feature of placenta accreta: deficiency of the decidua basalis. Differential diagnostic considerations, including abdominal pregnancy and trophoblastic disease, also are discussed.

Placenta accreta: prospective sonographic diagnosis in patients with placenta previa and prior cesarean section

“…Recently Hoffman-Tretin and coworkers provided confirmation of this observation, noting venous lakes in six of seven patients with one or more earlier cesarean sections, current placenta previa, and surgical and his+ tologic presence of placenta accreta requiring hysterectomy. 3 In two of the Hoffman• Tretin patients, Doppler interrogation of the outer placental margin revealed venous flow in regions where a hypoechoic myometrial zone was present, but not in areas where this zone was absent. Although the use of Doppler may provide ancillary evidence of placenta accreta, we believe both pulsed and color flow Doppler would still be subject to false-positive interpretation from scar windows and false-negative results when placenta previa-accreta is associated with increased anastomotic uterine serosal vascular supply, an observation seen in at least four of the cases in our own series.…”

“…1 and 2), (2) thinning, irregularity, or focal disruption of the linear hyperechoic uterine serosa-bladder wall complex (Fig. 3), and (3) presence of focal mass-like elevations or extensions of tissue with the same echogenicity as placenta beyond the uterine serosa, whether seen through the distended bladder or cephalad or lateral to the bladder (Fig. 4).…”

“…A B Figure 2 Loss of the myometrial zone without thinning or distortion of the serosal echogenic complex in two patients FlNBERG AND WILLIAMS 335 these formations had been found to be associated with placenta accreta in two other clinical studies.z. 3 With the exception of one patient scanned at 22.5 weeks, and another at 25 weeks, all patients were evaluated in third trimester. The generally advanced stage of pregnancy at entrance into this study is a reflection of the referral nature of our practice, with consultation most often requested by the primary care obstetrician only after a clinically significant event.…”

Three-dimensional ultrasonography and diagnosis of placenta percreta with bladder involvement.

“…Gray-scale real-time ultrasonography, preferably using the transvaginal approach in cases of anterior placenta previa, should be the primary screening tool. The criteria for suspecting placental invasion are well known [5][6][7] and may be summarized as follows:…”

Ultrasound Imaging of Postpartum Hemorrhage

“…however, it is one of the more obvious findings at screening evaluation and should prompt a detailed evaluation for other ultrasound markers. 29 Color and/or power Doppler reveals hypervascularity of the interface between the uterine serosa and the bladder wall (Fig. 17).…”