Scoring patients for VBAC

Dr. Mozurkewich responds:

Thank you, Dr. Hakim-Elahi, for your comments. To my knowledge, none of the scoring systems designed to predict failed trial of labor have proven reliable.

In an assessment of several models, Macones and colleagues reported a bestmodel sensitivity for prediction of failed trial of labor of 77%, with a specificity of 65%.¹ This means that 35% of women discouraged from undergoing a trial of labor under this system would have achieved vaginal delivery. Other investigators have reported on scoring systems with similar test characteristics.^2,3 In a decision analysis, Macones suggested that an ideal system should have both sensitivity and specificity in excess of 75% in order “to obtain a reasonable trade-off between reduction in morbidity and the total rate of cesarean sections.”⁴ In the absence of a validated scoring system meeting these requirements, our institution continues to select and counsel candidates for trial of labor according to published ACOG guidelines.⁵