This time-lapse 3D medical animation shows the stations of presentation during labor (labour) and childbirth. The animation follows the baby's
progress through the mother's birth canal, marking the baby's position by how her head lines up with specific points in the mother's bony pelvis. These points are called vertex positions, and use the designations +3, +2, +1, 0, -1, -2 -3 in what obstetricians (OB/GYNs) call the 1/3 system.