Sonographic Predictors of Antepartum Bleeding in Placenta Previa.

Of 149 women with placenta previa, 37% had VB and 15% had VB requiring delivery. Women with VB requiring delivery had significantly more episodes of VB than those who did not require delivery for VB (1.5, interquartile range (IQR) [1-3] vs 1.0 [1-5]; p=0.001). In univariate analysis, women with VB had decreased CL (3.9 cm vs. 4.2 cm; p<0.01) compared with those without. Women with VB requiring delivery had increased DPO (2.6 cm IQR [1.7-3.3] vs. 1.5 cm [1.1-2.4], p=0.01) compared to those without. After adjusting for confounders, only CL<4cm remained independently associated with increased risk of VB (aOR 2.27, 95% confidence interval CI) [1.12-4.58], p=0.01). None of the measures were predictive of either outcome (AUC <0.65) Conclusion: Decreased CL may be associated with risk of VB in placenta previa.