Analysis Of Risk Factors And Clinical Outcomes Of Placental Accreta Disease

Objectives: This study aimed to analyze the general clinical characteristics of PAS patients and the perioperative managements and clinical outcomes of different types of PAS to analysis risk factors of PAS,establishe a prediction model for the occurrence of PAS,guide the layered management of PAS patients and the implement of targeted treatment for different types of PAS.Simultaneously,clinical data of patients with cicatricial uterus complicated with placenta previa during the second trimester were collected to analyze the safety and effectiveness of different methods of labor induction,so as to provide evidence for the selection of labor induction methods for such patients.Methods: The study was divided into two parts.Part Ⅰ:The data of pregnant women with late single pregnancy who delivered by cesarean section in the First Affiliated Obstetrics Department of Kunming Medical University from January 1,2017 to December 31,2022 were collected,262 cases diagnosed with placenta accreta of which were set as the research group and other 275 cases without placenta accreta of which were set as the control group.The data of the two groups were analyzed to compare the risks of PAS,and the prediction model of PAS was built by logistic regression model to provide evidence for the prevention and prenatal diagnosis of PAS.According to the degree of placenta accretion,the research group was divided into placenta accreta group,placenta inrcreta group and placenta percreta group,and the clinical outcome of different types of PAS patients was analyzed by comparing the operation-related indexes and the birth situation of newborns in each group.Part Two: Patients with a cesarean section history and complicated with placenta previa during this pregnancy who performed labor induction in the First Affiliated Obstetrics Department of Kunming Medical University from January 1,2017 to December 31,2022 were objectives of this study.Based on different methods of labor induction,these 45 patients with placenta previa in the second trimester of cicatricial uterus were divided into three groups.10 cases belonged to abdominal hysterotomy group;14 cases belonged to mifepristone + misoprostol group;and 21 cases belonged to mifepristone + rivanol group.The clinical outcomes of the three groups were compared and analyzed to probe into delivering modes of labor induction of such patients.The clinical characteristics of different placenta previa status,placenta position,and whether prophetic uterine artery embolization was used were analyzed.Results: Part Ⅰ:(1)Risk Factors for PAS: Old age,BMI≥28,number of pregnancies,number of abortions,number of cesarean sections,placenta previa,central type of placenta previa,anterior wall placenta,female infant,IVF,and interval from previous cesarean section to last menstrual period were risk factors for PAS(P<0.05).Among them,placenta previa(OR=8.842,95%CI 5.288-15.172,P<0.05),anterior wall placenta(OR=1.807,95%CI 1.081-3.045,P<0.05),cesarean deliveries(OR=3.189,95%CI 1.831-5.618,P<0.05)、IVF(OR=4.38,95%CI 1.976-10.155,P < 0.05),IVF(OR=4.38,95%CI 1.976-10.155,P < 0.05)and female infants(OR=1.749,95%CI 1.125-2.738,P<0.05)were independent risk factors for PAS.And the number of induced abortions ≥2 is related to the occurrence of PAS(OR=1.672,95%CI 0.979-2.865,P<0.1).Vaginal birth was a protective factor for PAS(OR=0.458,95%CI 0.132-1.475,P<0.05).(2)Establishment of prediction model: the area under Receiver operator characteristic curve of PAS prediction model based on high risk factors was 0.856(95%CI0.8240.887),with the sensitivity of 0.773 and the specificity 0.804.After testing,the model had good differentiation,calibration,and prediction efficiency.(3)Outcome of pregnant women:(1)Comparison between research group and control group showed that there were statistical differences in blood loss,blood transfusion(suspended red,plasma),blood transfusion cases,autologous blood transfusion,postoperative hospitalization days,hospitalization costs,local focus excision,ureteral stent placement,intervention,balloon tamponade,gauze tamponade,uterine artery embolization,uterine artery ligation,B-lynch suture,hysterectomy,unplanned secondary,hemorrhagic shock,ICU transfer rate(P < 0.05);while there were no significant differences in bladder repair and thrombosis(P > 0.05).(2)Comparing between any two groups related indexes and complications of the placenta accreta group,placenta increta group,placenta percreta group and non-PAS group,it can find that there were statistical differences in blood loss,number of blood transfusions,postoperative hospitalization days and hospitalization costs among all groups(P < 0.05),and the placenta percreta group > placenta increta group > placenta accreta group > control group.The transfusion volume of blood products in placenta penetration group was significantly higher than that in other groups(P < 0.05).Autologous blood transfusion was mainly applied in placenta increta and placenta percreta group,including 9 cases in placenta increta group and 14 cases in placenta percreta group,with statistical difference(P < 0.05).Hospitalization costs were almost four times higher in the placenta percreta group than in patients without PAS.Overall,the placental percreta group had the worst prognosis,followed by the placental increta group;and the placental accreta group had the same prognosis as the control group.A total of 30 patients underwent hysterectomy,all of which were in the research group.Among them,19 patients underwent direct hysterectomy without placenta stripping,and 11 patients underwent hysterectomy immediately after placenta stripping because they could not effectively stop bleeding.After comparison,there was a statistical difference in the amount of blood loss between the two patients,and those who attempted placenta stripping were significantly greater than those who did not attempt placenta stripping(P < 0.05).In the placental percreta group,compared with patients in the same group who did not receive interventional therapy,blood loss was not significantly increased(P>0.05).There were 9 cases of common iliac artery and 9 cases of abdominal aorta.There was no significant difference in blood loss between the two groups(P > 0.05).(4)Outcome of newborns: In the comparison between the research group and the control group,there were statistically significant differences in neonatal birth weight,NICU conversion rate,interventionated preterm birth,gestational age at birth,Apgar score(P < 0.05),but no statistically significant differences in neonatal asphyxia rate(P > 0.05).The preterm birth rate in the placenta aatercca group and placenta increta group was higher than that in the placenta percreta group and control group(P < 0.05),but there was no statistical difference between the former two groups and the latter two groups(P > 0.05).The asphyxia rate in placenta percreta group was significantly higher than that in other groups(P < 0.05).(5)Part Two:(1)There were no statistical differences among the three groups in age,number of pregnancies,number of vaginal births,number of abortion,number of cesarean section,pregnancy interval,cause of labor induction,IVF,twins,anterior wall placenta,central placenta previa status,placenta accreta,etc.There were statistical differences in gestational weeks between mifepristone + misoprostol group and hysterectomy group and mifepristone + Rivanol group(P < 0.05),but no statistical differences in gestational weeks between the latter two groups(P >0.05).The median blood loss in the hysterectomy group was 550 ml,which was significantly higher than that in the other two groups(200ml/200ml)(P < 0.05),but there was no significant difference in blood transfusion volume(P > 0.05).All patients in the three groups received preventive uterine artery embolization and uterine tamponade for hemostasis,and there was no statistical difference(P > 0.05).There were no significant differences in placenta residue and unplanned secondary admission among the three groups(P < 0.05).The length of hospital stay and cost in hysterotomy group were significantly higher than those in mifepristone +misoprostol group and mifepristone + rivanol group(P < 0.05),and there was no statistical difference between the latter two groups(P > 0.05).(2)There were statistical differences among different types of placenta previa status(P < 0.05).The UAE utilization rate,hospitalization cost and fever rate after labor induction in the central type group were significantly higher than those in the non-central type group(P < 0.05),but there was no statistical difference in blood loss and other data(P > 0.05).(3)There was no significant difference in the delivery mode of different placental body positions(P < 0.05).The placenta previa status was mainly central type(84.6%)in the anterior wall placenta group,and the placenta implantation rate and hospitalization cost were significantly higher than those in the non-anterior wall placenta group(P < 0.05),but there were no significant differences in blood loss and UAE utilization rate(P > 0.05).(4)The blood loss in UAE plus drug induced labor group was significantly lower than that in drug induced labor group(P < 0.05),and the hospitalization cost was significantly higher than that in drug induced labor group(P < 0.05).There were no statistical differences in the success rate of labor induced labor,complications and other data between the two groups(P > 0.05).Conclusions: 1.Old age,BMI≥28,pregnancy number,abortion number,cesarean section number,placenta previa,placenta location,female infants,IVF and gestational age of first hemorrhage might be the risk factors for PAS,among which the previous cesarean section number ≥2,placenta previa,placenta body in the anterior wall,cesarean section number,IVF and female fetus might be independent risk factors for PAS.The number of abortion ≥2 might be correlated with the occurrence of PAS.Vaginal delivery might be a protective factor for PAS.2.The prediction model created based on high risk factors has good differentiation and calibration,and has good prediction efficiency,which can provide theoretical basis for the pre-pregnancy guidance and pregnancy care of PAS.3.PAS has great harm to pregnant women,and the prognosis of mothers and children with penetrative placenta accreta might be the worst.When placental penetration is severe and there is no need for fertility,direct hysterectomy without placental dissection could reduce the amount of blood loss.In the placental percreta group,intravascular balloon occlusion could not effectively reduce the amount of blood loss,and the choice of blood vessel occlusion may have no effect on the amount of blood loss.4.During labor induction during pregnancy in patients with cicatra-uterus complicated with placenta previa,if there is central placenta previa,placenta is located in the anterior wall,prenatal diagnosis or high suspicion that the placenta penetrates the surrounding organs hysterectomy could be recommended.5.Vaginal labor induction during pregnancy might be safe and feasible for patients with cicatricial uterus combined with placenta previa,and it might be not increase the occurrence of complications.Mifepristone combined with misoprostol and mifepristone combined with rivanol have similar effects and safety in inducing labor.Preventive uterine artery embolization could effectively reduce the amount of blood loss in patients with vaginal induction of labor.