Risk Factors and Pregnancy Outcome in Women With a History of Cesarean Section Complicated by Placenta Accreta
Authors: Liang Yingyu , Zhang lizi , Bi Shilei , Chen Jingsi , Zeng Shanshan , Huang Lijun , Li Yulian , Huang Minshan , Tan Hu , Jia Jinping , Wen Suiwen , Wang Zhijian , Cao Yinli , Wang Shaoshuai , Xu Xiaoyan , Feng Ling , Zhao Xianlan , Zhao Yangyu , Zhu Qiying , Qi Hongbo , Zhang Lanzhen , Li Hongtian , Du Lili , Chen Dunjin 
Published: December 2020

Abstract
Objective: To explore the risk factors and pregnancy outcomes in women with a history of cesarean section complicated by placenta accreta.Methods: This retrospective study included clinical data from singleton mothers with a history of cesarean section in 11 public tertiary hospitals in 7 provinces of China between January 2017 and December 2017. According to the intraoperative findings or the pathologic diagnosis after delivery, the study population was divided into placenta accreta (PA) and non-PA groups. We compared the pregnancy outcomes between the 2 groups, used multivariate logistic regression to analyze the risk factors for placental accreta, and used receiver operating characteristic curves to evaluate the value of the risk factors.Results: For this study we included 11,074 pregnant women with a history of cesarean section; and of these, 869 cases were in the PA group and 10,205 cases were in the non-PA group. Compared with the non-PA group, the probability of postpartum hemorrhage, severe postpartum hemorrhage, diffuse intravascular coagulation, puerperal infection, intraoperative bladder injury, hysterectomy, and blood transfusion was significantly increased in the placenta accreta group (P<0.05)). At the same time, the rate of neonatal low-birth weight, the probability of neonatal comorbidities, and the rate of neonatal intensive care unit admission also increased significantly (P<0.05). Weight, parity, number of miscarriages, number of previous cesarean sections, history of premature rupture of membrane, previous cesarean-section transverse incisions, history of placenta previa, and the combination of prenatal hemorrhage and placenta previa were all independent risk factors for placenta accreta; while non-Han ethnicity was an independent protective factor for placenta accreta (P<0.05). The area under the ROC curve (AUC) was 0.93 (95% CI=0.92-0.94); and the specificity, sensitivity, and accuracy rate were 0.87, 0.93, and 0.93, respectively.Conclusions: There was an increased risk of adverse outcomes in pregnancies complicated by placenta accreta in women with a history of cesarean section, and this required close clinical attention. Weight before pregnancy, parity, number of miscarriages, number of previous cesarean sections, Han ethnicity, history of premature rupture of membranes, past transverse incisions in cesarean sections, a history of placenta previa, prenatal hemorrhage, and placenta previa were independent risk factors for pregnancies complicated with placenta accreta in women with a history of cesarean section. These independent risk factors showed a high value in predicting the risk for placental accreta in pregnancies of women with a history of cesarean section.