Value Of Ultrasound Scoring In Assessing The Risk Of Pernicious Placenta Previa Accreta And Poor Pregnancy Outcomes

Objective: To evaluate the value of ultrasound scoring system for predicting the risk of pernicious placenta previa(PPP)combined with placenta accreta(PA)and poor pregnancy outcomes.Methods: This is a prospective study of women with PPP at ?28 weeks' gestation based on ultrasound diagnosis from December 2016 to December 2017 in our center.Transabdominal or transvaginal ultrasound is used to assess PA and poor pregnancy outcomes with the scoring system involving uteroplacental demarcation,number and size of lacunae,bladder line,lacunae and placental basal blood flow.Each item is assigned 0to 2 points,and the sum yields the final score.Diagnosis of PA is based on surgery or pathology.Following up with pregnancy outcomes,at least one of the three PA complications with postpartum hemorrhage(PPH)?1000ml,hysterectomy and organ involvements is thought to be the poor pregnancy outcomes.The value of ultrasound scoring system is performed by a receiver operating characteristic curve(ROC)and correlation analysis.Results: 51 PPP women,36(70.6%)has PA,of which 27(75%)with poor pregnancy outcomes.?The area under the curve(AUC)for PA diagnosis is 0.887(95%confidence interval(CI),0.798-0.977).The score is ?2 points with the sensitivity 100%;?5 points which has the maximal Youden index with the sensitivity 86.1% and specificity 73.3%;?8 points with the specificity 100%.?AUC is 0.940(95%CI,0.836-0.987)for predicting poor pregnancy outcomes.The score is ?5 points with the sensitivity 100%;?8 points with the sensitivity 70.3% and specificity 100% for the maximal Youden index.?The system has the clinical reference value for PPP with PA and poor pregnancy outcomes:The score is <2 points with the incidence of PA 0%(0/4);the incidence of PA is 36.4%(4/11)and poor outcomes in pregnancy 0%(0/4)for 2 ?score <5;the incidence of PA is76.5%(13/17)and 61.5%(8/13)poor outcomes for 5?score<8;the incidence of PA100%(19/19)and poor pregnancy outcomes 100%(19/19)happens in ?8 points.?According to the correlation analysis,PA and PPH are correlated,the higher the score,the more the amount of postpartum hemorrhage,the score?10 points with 63.6% of the abdominal aorta surgery.Conclusion: The ultrasound scoring system predicting PPP with PA and poor pregnancy outcomes is of highly diagnostic accuracy.When 2?score<5,the probability of poor pregnant outcomes is very low;?5 points,the incidence of PA is very high;?8 points,PA and poor pregnant outcomes will all happen,PPH is always the most common poor outcomes,the higher the score,the more the amount of postpartum hemorrhage,the greater the difficulty of surgery,and preoperative arterial intubation is the best preventive intervention when necessary.