The anterior shoulder hinges below the symphysis pubis and with continuous descent the posterior shoulder is delivered first by lateral flexion of the spines followed by anterior shoulder then the body. There is less blood loss and less liability for retention of fragments. The lower edge of the placenta separates first and placenta is delivered side ways. There is more liability of bleeding and retained fragments. It is due to obstruction of the venous return from the lower part of the scalp by the cervical ring.
Caput succedaneum disappears spontaneously within hours to days of birth.
As it is a vital manifestation, so it is not detected in intrauterine foetal death.