Prenatal Diagnosis Of Ultrasonographic Scoring System In Placenta Previa With Placenta Accreta

Objective To explore the diagnostic value of prenatal ultrasonographic scoring system in placenta previa complicated with placenta accreta. Methods A total of 204 pregnant women with placenta previa who were given antenatal ultrasound examinations and cesarean section from January 2012 to June 2015 as study subject. Based on clinical surgery and/or pathological results as the gold standard, all of cases were divided into placenta accreta group and non-placenta accreta group. Univariate analysis and multiple logistic regression analysis were used in screening out the sonographic parameters closely related to placenta accreta. Then establish a scoring system, whose diagnostic value were evaluated by receiver operating characteristic(ROC) curve. Results(1) The rates of age ≥ 35 years, gravidity ≥ 3 times, parity ≥ 2 times and cesarean delivery ≥ 2 times on placenta accreta group were more than those on non-placenta accreta group(P<0.05). The rates of postpartum hemorrhage,hysterectomy,preterm and neonatal asphyxia on placenta accreta group were significantly higher than those on non-placenta accreta group(P<0.01).(2) The logistic regression identified 4 sonographic parameters, including loss of retroplacental clear space, smallest sagittal myometrial thickness, abnormal vasculature of uterine-bladder interface and lacunar flow distributed within placenta parenchyma. Different scores were assigned according to the odds ratio(OR) of these parameters.(3) When a score of 3 was used as the cutoff value for diagnosing placenta accreta by ROC curve, the sensitivity, specificity, positive predictive and negative predictive were 88.1%, 94.9%, 89.4% and 94.2% respectively. The area under ROC curve was 0.948. Conclusion Placenta previa increta threatens the lives of the mother and the fetus because of massive hemorrhage. Prenatal ultrasonographic scoring system has good diagnostic value for placenta previa with placenta accreta.