Fetal Presentation

Fetal position is defined as designation of landmark of fetal presenting part (occiput, mentum, sacrum, scapula) to right or left, and anterior, posterior, or transverse portion of the woman's pelvis.

A three-letter abbreviation is used to describe the relationship of the presenting part to the maternal pelvis.

• Sides of presenting part facing in the pelvis are described as: R (right) or L (left).
• Landmarks of presenting part are described as: O (occiput, or head), S (sacrum), Sc (scapula, or shoulders), M (mentum, or chin).
• Directions of presenting part facing in the pelvis are descreibe as: A (anterior, or front), P (posterior, or back), or T (transverse).

The first and third letters relate to the pelvis, and the second letter relates to the fetus.


Common possible fetal presentations are :

VERTEX / OCCIPITAL PRESENTATION
LOA = Left Occipital Aterior
LOT = Left Occipital Transverse
LOP = Left Occipital Posterior
ROA = Right Occipital Anterior
ROT = Right Occipital Transverse
ROP = Right Occipital Posterior

FACE PRESENTATION
LMA = Left Mentum Anterior
LMT = Left Mentum Transverse
LMP = Left Mentum Posterior

BREECH PRESENTATIONS
LSA = Left Sacrum Anterior
LST = Left Sacrum Transverse
LSP = Left Sacrum Posterior


Here are images of fetal presentation :



click image to enlarge.