Is Cervical Length a Useful Predictor of Antepartum Hemorrhage in Patients with Placenta Previa?

Objective: Placenta previa complicates 0.3-0.5% of pregnancies and can cause sudden antepartum massive hemorrhage (APH). Previous studies have indicated that cervical length (CL) measured by transvaginal ultrasonography may be a predicting parameter for APH in patients with placenta previa; however, conflicting data exist. Thus, we investigated the association between CL and APH in patients with placenta previa.

Methods: In total, 129 singleton pregnant women with placenta previa, who delivered at our institution from January 2010 to December 2016, were included in this study. The shortest CL measured throughout gestation was used for analysis, and we defined CL less or more than 30 mm as short or normal CL, respectively. We performed univariate and multivariate analyses, and a receiver-operating characteristics (ROC) curve was plotted to determine the cut-off CL value to predict APH.

Results: APH occurred in 26 patients. The adjusted odds ratio for APH was 3.80 (95% CI, 1.36-10.65) in patients with short CL. ROC analysis was performed to determine a cut-off CL value of 35 mm to predict APH, with a sensitivity of 80.7% and a specificity of 60.2%.

Conclusions: Our data indicated that CL measurements may be useful in determining patients at high risk of APH.