(2)
Specific points on the fetus.
(a) Cephalic or head presentation.
1 Occiput (O). This refers to the Y sutures on the top of the head.
2 Brow or fronto (F). This refers to the diamond sutures or
anterior fontanel on the head.
3 Face or chin presentation (M). This refers to the mentum or
chin.
(b)
Breech or butt presentation.
1 Sacrum or coccyx (S). This is the point of reference.
2 Breech birth is associated with a higher perinatal mortality.
(c)
Shoulder presentation.
1 This would be seen with a transverse lie.
2. Scapula (Sc) or its upper tip, the acromion (A) would be used
for the point of reference.
(3)
Coding of positions.
(a) Coding simplifies explaining the various positions.
1 The first letter of the code tells which side of the pelvis the fetus
reference point is on (R for right, L for left).
2 The second letter tells what reference point on the fetus is being
used (Occiput-O, Fronto-F, Mentum-M, Breech-S, Shoulder-Sc or A).
3 The last letter tells which half of the pelvis the reference point is
in (anterior-A, posterior-P, transverse or in the middle-T).
(b) Each presenting part has the possibility of six positions. They are
normally recognized for each position--using "occiput" as the reference point.
1 Left occiput anterior (LOA).
2 Left occiput posterior (LOP).
3 Left occiput transverse (LOT).
MD0921
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