Mueller-Hillis maneuver and angle of progression: Are they correlated?

Objective: Mueller-Hillis maneuver (MHM) and angle of progression (AOP) measured by transperineal ultrasound have been used to assess fetal head descent during the second stage of labor. We aimed to assess whether AOP correlates with MHM in the second stage of labor. Method: A prospective observational study including women with singleton pregnancy in the second stage of labor was performed. The AOP was measured immediately after the Mueller-Hillis maneuver. A receiver-operating characteristics (ROC) curve analysis was performed to determine the best discriminatory AOP cut-off for the identification of a positive MHM. A p-value less than 0.05 was considered statistically significant. Results: One hundred and sixty-six (166) women were enrolled in the study and 81.3% (n = 135) had a positive MHM. The median AOP was 143 degrees (106 degrees to 210 degrees). The area under the curve for the prediction of a positive maneuver was 0.619 (p = 0.040). Derived from the ROC curve, an AOP of 138.5 degrees had the best diagnostic performance for the identification of a positive MHM (specificity of 65% and a sensitivity of 67%). Conclusion: An AOP of 138 degrees seems to be associated with a positive MHM in the second stage of labor.