Prenatal Diagnosis Of Ultrasonographic Scoring Systemin Placenta Previa With Placenta Increta And Percreta

Objective: To evaluate the value of prenatal ultrasound scoring system for predicting the risk of placenta previa with placenta increta/percreta.Methods: A total of 363 pregnant women with placenta previa who were hospitalized and given cesarean section from January 2015 to December 2017 were included.Depending on clinical-surgical and/or pathological diagnosis,the study was divided into two groups:placenta increta/percreta group and non-placenta invasion/placenta accreta group.The ultrasound parameters were analyzed by univariate analysis and multiple logistic regression,then established the prenatal ultrasound score system.The diagnostic value of the receiver was evaluated by the operating characteristic curve.Results:1.The incidence of placenta previa with placenta invasion in our hospital increased year by year;2.The rates of gravidity?2 times,parity?1 times,abortion,cesarean sections and complete placenta previa were higher in placenta increta/percreta group(P<0.05).The rates of intraoperative hemorrhage ?1000ml,hysterectomy,preterm delivery and need for admission to neonatal intensive care unit were higher in placenta increta/percreta group(P < 0.05);3.Logistic regression analysis showed that thickness of the placenta,lacunnr flow distributed within palcenta parenchyma,focal exophytic mass,loss of clear space,smallest sagittal myometrium thickness,blood flow signals at the placenta base,cervical and peripheral blood flow signal were contributed to the establishment of logistic regression model,in which loss of clear space has largest OR value;4.The area under the ROC curve of the ultrasound score was 0.915.When a score of 4 points as the cutoff,the sensitivity,specificity,positive predictive value and negative predictive value were 75.8%,90.0%,81.3% and 86.7%;When a score of 5 points as the cutoff,they were 47.0%,99.6%,98.4% and 76.7% respectively.Conclusion:1.Increasing gravidity or parity,abortion,cesarean section and complete placenta previa are risk factors for placenta increta/percreta in placenta previa,which can lead to poor pregnancy outcomes.2.The study provided the predictive value of each ultrasound index,which loss of clear space has the most weight.3.The prenatal ultrasound score has a good value for predicting the presence of PI/PP in patients with placenta previa,which the best diagnostic cut-off point is 4 points.The area under the ROC curve is 0.915.