Malpresentation

In early pregnancy fetuses have a variable lie within the uterus. As the pregnancy approaches the latter part of the third trimester, the majority of singleton pregnancies have a longitudinal lie and the fetus enters the pelvis with a cephalic presentation. Transverse lie, compound presentation, face presentation, and brow presentation together account for less than 1% of fetal positions at term. Such noncephalic presentations are referred to as malpresentation. Malpresentation can recur in subsequent pregnancies. This chapter explores what percentage (diagnostic test characteristics) are associated with known risk factors of breech presentation. It examines the effectiveness of cesarean delivery in improving maternal and fetal outcomes compared to planned breech vaginal delivery. The chapter provides information on the risks of undergoing external cephalic version (ECV) compared to not undergoing ECV, and the maternal and fetal characteristics that predict a successful ECV.