EP15.03: Does a short cervix predict antepartum massive hemorrhage in patients with placenta previa?

Abstract

Placenta previa complicates 0.3 - 0.5% of pregnancies and can cause antepartum and/or intrapartum massive hemorrhage, which often necessitates allogenic blood transfusion and/or hysterectomy, rarely leading to maternal death. A useful clinical predictor of identifying patients at high risk for massive hemorrhage has been awaited. As several recent retrospective studies indicate, cervical length (CxL) measured by transvaginal ultrasonography may be a predicting parameter for antepartum massive hemorrhage (AMH) in cases with placenta previa. However, conflicting data exist. Thus, we evaluated if a short cervix is associated with eventual AMH in patients with placenta previa. A retrospective chart review was performed on 129 singleton pregnancies with placenta previa who delivered at our institution from January 2010 to December 2016, and information on patient characteristics and clinical course was collected. The shortest CxL measured throughout gestation in each patient was used for analysis. A receiver-operating characteristics (ROC) curve was plotted to determine the cut-off CxL value in the prediction of AMH defined as bleeding that was uncontrollable and/or over 100 ml. Statistical evaluation also included univariate and multivariate analysis. Institutional Review Board approval was obtained for the study. AMH occurred in 26 patients, and all of them required emergency Caesarean section. ROC analysis determined a cut-off CxL of 35 mm in the prediction of AMH, with a sensitivity of 81% and a specificity of 60%. The area under the curve was 0.74, and the positive and negative predictive values were 34% and 93%, respectively. The adjusted odds ratio for AMH was 5.2 (95% CI, 1.7 – 15.4) in patients with a CxL at or below 35 mm (n = 62), and the ratio for AMH in those with at least one episode of antepartum minor hemorrhage (n = 50) was 5.2 (95% CI, 1.9 – 14.1). Our data indicate that CxL measurements may be useful in determining high-risk patients for AMH.