Ultrasonographic fetal head position to predict mode of delivery: a systematic review and bivariate meta-analysis.

OBJECTIVE We performed a systematic review to determine whether sonographic assessment of occipital position of the fetal head can contribute to the prediction of the mode of delivery. METHODS We performed a systematic literature search of electronic databases from inception to May 2011. Two reviewers independently extracted data from the included studies. We used a bivariate model to estimate point estimates for sensitivity and specificity curves for the outcome Cesarean delivery. Eligible studies were cohort studies or cross-sectional studies that reported on both the position of the fetal head, as assessed by ultrasound, before or at the beginning of active labor as well as the outcome of labor in women at term. RESULTS We included 11 primary articles reporting on 5053 women, of whom 898 had a Cesarean section. All studies indicated disappointing values for sensitivity and specificity in the prediction of Cesarean section. Summary point estimates of sensitivity and specificity were 0.39 (95% CI, 0.32-0.48) and 0.71 (95% CI, 0.67-0.74), respectively. CONCLUSION Sonographic assessment of occipital position of the fetal head before delivery should not be used in the prediction of mode of delivery.