Page 744 - Saunders Comprehensive Review For NCLEX-RN

Face Presentations

RMA: Right mentoanterior
LMA: Left mentoanterior
RMP: Right mentoposterior

Breech Presentations

LSA: Left sacroanterior
LSP: Left sacroposterior

Other Presentations

Brow presentation
Shoulder presentation

Box 23-2

Mechanisms of Labor

Engagement

▪ Engagement is the mechanism whereby the fetus nestles into the pelvis.
▪ Engagement occurs when the presenting part reaches the level of the ischial
spines.

Descent

▪ Descent is the process that the fetal head undergoes as it begins its journey
through the pelvis.
▪ Descent is a continuous process from prior to engagement until birth and is
assessed by the measurement called station.

Flexion

▪ Flexion is a process of nodding of the fetal head forward toward the fetal chest.

Internal Rotation

▪ Internal rotation of the fetus occurs most commonly from the occipitotransverse
position, assumed at engagement into the pelvis, to the occipitoanterior position
while continuously descending.

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