EP01.01: Prediction of severe hemorrhage in placenta previa/accreta using ultrasound and clinical risk factors

To evaluate the value of ultrasound and clinical risk factors in predicting severe hemorrhage (>1.5 l) in pregnancies undergoing Caesarean section for placenta previa/accreta. A retrospective review of all cases of placenta previa/accreta undergoing Caesarean delivery over a period of 5 years in a regional service unit. Cases were identified and delivery data was retrieved from a comprehensive obstetric database. Detailed ultrasound findings from the examination just before delivery were obtained from manual review of individual records. There were a total of 21908 deliveries within the review period of 2012 to 2016, and the incidence of Caesarean section for placenta previa/accreta was 0.98% (n=215). Of these, 12.1% (n=26) had severe postpartum hemorrhage (PPH) with blood loss of 1.5 l. There were 6 cases of placenta accreta (2.8%), of which one had classical Caesarean section with the placenta left in situ and another had classical section and direct hysterectomy, so that both of them did not have severe PPH. Univariate analysis showed that advanced maternal age, previous pregnancies with previa or PPH, the type of previa or distance of the placental edge from the os, occurrence of antepartum hemorrhage before delivery, anterior placenta, thick placental edge and presence of accreta were all significantly associated with severe PPH. A logistic regression model showed that major previa, APH before delivery and anterior placenta remained significant factors associated with severe PPH, whereas other factors were excluded. Due to the differential treatment for accreta cases, placenta accreta was not a significant factor in the final equation. The sensitivity/specificity and positive/negative predictive value of the model for severe hemorrhage are 61.5%, 96.8%, 72.7% and 94.5% respectively. The significant ultrasound and clinical factors identified as predictive factors for severe PPH could be used as a model for triaging risks when planning Caesarean section delivery for placenta previa/accreta. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.