Prediction of Version Outcomes for External Maneuvers of Breech Fetus by Assessment of Breech Progression Angle

Breech presentation complicates about 3-4% of single pregnancies at term. Although vaginal delivery is also possible in breech presentations, this is associated with an increased risk of fetal morbidity and mortality. The cephalic version for external maneuvers is an obstetric procedure that allows conversion of an abnormal presentation/situation (breech or transverse) to a cephalic presentation by applying pressure to the maternal abdomen. Over the years, many authors have analyzed numerous factors that might be associated with an increased likelihood of successful maneuvering. Over time, transperineal ultrasonography has proven to be a valid, objective, and highly reproducible tool for the assessment of fetal head progression during delivery in conjunction with examination. The Angle of Progression (AoP) is the angle between the line passing through the longitudinal axis of the pubic symphysis and the line passing through the inferior border of the pubic symphysis and tangent to the fetal skull. AoP is an accurate and reproducible parameter for the assessment of fetal head descent during labor, with a strong correlation with the mode of delivery. The investigators are not aware of any studies that have established the role of transperineal ultrasound in assessing podietal engagement and its role in predicting the success of the cephalic version maneuver, an aspect the investigators want to explore with this study.