The document discusses the relationship of the fetus to the uterus and pelvis during pregnancy and birth. It defines lie, presentation, presenting part, position, attitude, and denominator. The lie refers to the orientation of the fetus, which is usually longitudinal but can also be transverse or oblique. The presentation is the part of the fetus occupying the lower uterus, most commonly the head (cephalic) but also the breech or shoulders. The presenting part is the portion overlying the internal os. Position refers to the relationship between the denominator (occiput, sacrum, etc.) and maternal pelvis quadrants. Attitude describes the flexion of fetal parts. Common presentations, positions, attitudes, and denominators are defined in