Abstract: Objective To investigate the imaging features and predictive value of penetrating and pernicious placenta previa (PPP) based on magnetic resonance imaging (MRI) and color Doppler ultrasonography (CDUS). 
Methods In total, 70 pregnant and parturient women with PPP who were admitted to our hospital were selected as the research subjects, and all of them underwent MRI and CDUS examination. The diagnostic value of MRI and CDUS alone and in combination for PPP was analyzed.The characteristics of MRI and CDUS in non-penetrating PPP and penetrating PPP in pregnant and parturient women were compared, and the prognostic factors of penetrating PPP in pregnant and parturient women were analyzed.Receiver operating characteristic (ROC) curve was used to evaluate the predictive value of MRI and CDUS scores for the prognosis of pregnant and parturient women with penetrating PPP. 
Results Among the 70 PPP patients, 52 had non-penetrating PPP and 18 had penetrating PPP. The diagnostic accuracy of MRI combined with CDUS was higher than that of single detection, but data comparison showed no statistical significance (P＞0.05). Compared with pregnant and parturient women with non-penetrating PPP, those with penetrating PPP had higher hysterectomy rate and more severe asphyxia in neonates (P＜0.05). Compared with the good prognosis group, the poor prognosis group had more cesarean sections, shorter delivery cycle, longer duration of operation, more intraoperative blood loss, and higher MRI and color Doppler scores (P＜0.05). Intraoperative blood loss, MRI score, and CDUS score were independent risk factors for poor prognosis of pregnant women with penetrating PPP (P＜0.05).The area under the ROC curve (AUC)of intraoperative bleeding, MRI score, and CDUS score were 0.806, 0.854, and 0.806, respectively, and the differences were statistically significant when compared with the AUC of combined detection (P＜0.05). 
Conclusion MRI and CDUS have high diagnostic value for penetrating PPP, and have certain predictive value for the prognosis of pregnant and parturient women and neonates. 

Key words: placenta previa, magnetic resonance imaging,  , ultrasonography, Doppler, color