According to the leading part, this is identified as a cephalic, breech, or shoulder presentation.

A shoulder presentation is an indication for a C/S.

Shoulder presentations are classified into four types, based on the location of the scapula:

The shoulder presentation was a feared obstetrical complication.

Impacted shoulder presentations contribute to maternal mortality.

Asynclitic presentation is significantly different from a shoulder presentation, in which the shoulder is presenting first.

Further, if the amniotic fluid sac ruptures the shoulder or arm may become wedged as a shoulder presentation.

The delivery of the second twin in a transverse lie with a shoulder presentation represents a special situation that may be amenable to a vaginal delivery.

Shoulder presentation is a malpresentation that is not to be confused with shoulder dystocia, a complication during the birth of a baby in a vertex presentation.

Presentation: Relationship between the leading fetal part and the pelvic inlet: cephalic, breech (complete, incomplete, frank or footling), face, brow, mentum or shoulder presentation.

Shoulder presentation with transverse lie are classified into four types, based on the location of the scapula (shoulderblade); note: this presentation needs to be delivered by cesarean section.

In the textbook Siegmundin presented a solution to the delivery of a shoulder presentation, in those days often catastrophic situation leading to the death of the baby and potentially the mother.

Shoulder presentations are uncommon (about 0.5% of births) as usually towards the end of gestation either the head or the buttocks start to enter the upper part of the pelvis anchoring the fetus in a longitudinal lie.

While a baby can be delivered vaginally when either the head or the feet/buttocks are the leading part, it usually cannot be expected to be delivered successfully with a shoulder presentation unless a cesarean section (C/S) is performed.

A shoulder presentation refers to a malpresentation at childbirth where the baby is in a transverse lie (its vertebral column is perpendicular to that of the mother), thus the leading part (the part that enters first the birth canal) is an arm, shoulder, or the trunk.

It is not known in all cases of shoulder presentation why the longitudinal lie is not reached, but possible causes include bony abnormalities of the pelvis, uterine abnormalities such as malformations or tumors (fibroids), and other tumors in the pelvis or abdomen can also lead to a shoulder presentation.