To investigate the value of various ultrasound parameters in the diagnosis of placenta accreta.

To retrospectively analyze the sonographic images of 112 patients with prental diagnosis of placenta previa at Xiangya Hospital of Central South University between April 2016 and July 2017. All patients were confirmed by surgery pathology. Pathology was as golden standard for diagnosis, and the sensitivitity, specificity, positive predictive value and negative predictive value of each ultrasound parameter in the prenatal dianosis of placenata accreta and the predicting postpartum hysterectomy of patients with placenta accreta were calculated.

Of 112 patients with placenta previa, 71 cases were confirmed with placenta accreta by histology, 41 cases without placenta accrete, accurate prenatal ultrasound diagnosis is 72 cases, the accuracy is 64.1%. Ultrasonic parameters assessed included loss of retroplacental clear zone, smallest myometrial thickness, presence of ″moth-eaten″ lacunar spaces, and sub-placental or the posterior wall of the bladder hypervascularity. The sensitivity (specificity) of diagnosis of placenta accreta was 83.10% (29.27%), 64.79% (73.17%), 43.66% (87.80%), 64.79% (58.54%), respectively, the positive predictive value (negative predictive value) was 67.05% (50.00%), 80.70% (54.55%), 86.11% (47.37%), 73.02% (48.98%), respectively, the loss of retroplacetal clear zone has high sensitivity and low specificity in the prenatal diagnosis of placenata accreta, the presence of ″moth-eaten″ lacunar spaces has the highest specificity. The sensitivity (specificity) of each ultrasound parameter to predict postpartum hysterectomy of patients with placenta accreta was 100% (25.53%), 77.78% (54.26%), 61.11% (73.40%), 83.33% (48.94%), respectively, the positive predictive value (negative predictive value) was 20.45% (100%), 24.54% (92.73%), 30.56% (90.79%), 23.81% (93.88%). The loss of retroplacetal clear zone has high sensitivity and low specificity in predicting the postpartum hysterectomy in patients with placenata accreta, and the presence of ″moth-eaten″ lacunar spaces has high sensitivity and specificity.

Ultrasound is important for the prenatal diagnosis of accreta placentation. The loss of retroplacental clear zone in the prenatal diagnosis of placenta accreta has high sensitivity and low specificity, and the presence of ″moth-eaten″ lacunar spaces has high specificity, and has some correlation with the pregnancy outcomes of patients with palcenta previa. Performing routine detailed placenta ultrasound examination for women with prior caesarean delivery presenting with a low-lying or a placenta previa is essential in improving the detection rate of placenta accreta.