Prediction of cesarean hysterectomy in placenta previa complicated with prior cesarean: a retrospective study.

BACKGROUND: The prevalence of both placenta previa and cesarean are on the rise. Multiple adverse outcomes are critically increased when placenta previa is subsequent to prior cesarean. The purpose of the present study is to develop a pre-surgical method for predicting adverse outcomes in pregnancy complicated with both placenta previa and prior cesarean.

METHODS: Clinical data was obtained from the medical history system at the First Affiliated Hospital of Sun Yat-sen University from February 2003 to December 2016. All cases with a final diagnosis of "placenta previa/low lying placenta (ICD:O44.001-105)" and "scarred uterus complicated with pregnancy (ICD: O34.200-202)" were collected and reviewed. Hysterectomy was taken as the primary outcome; and blood loss was taken as the secondary outcome.

RESULTS: Of 219 pregnant women in the final analysis, 25 received a hysterectomy following delivery, and 48 had blood loss exceeding 1000 ml. Pre-surgical risk factors for hysterectomy are ultrasonic signs of vascular lacunae, central placenta previa, and loss of normal hypoechoic retroplacental zone. A pre-surgical predictive equation referred to as "Hysterectomy Index in Placenta Previa with Prior cesarean (HIPs)" was generated and each risk factor was weighted to create an 8-point scale. This index yielded an area under the curve of 0.972 for the prediction of hysterectomy.

CONCLUSIONS: Application of the HIPs score may provide an effective pre-surgical prediction of cesarean hysterectomy in pregnant women complicated with both placenta previa and prior cesarean.