Which of the following fetal position is most favorable for birth?

Concept:

• Fetal lie, attitude, position, and station are the reference points to locate the position of the fetus.
• Fetal position refers to the relation of the presenting part of the fetus to the maternal pelvis.
• The position depends on the fetal occiput directing to the right or left side of the mother's pelvis (anteriorly or posteriorly).
• Therefore, the positions are:
  • Left occipito-anterior (LOA); Occiput is present anterior to the pubic bone of the left side of the mother's pelvis.
  • Right, occipito-anterior (ROA); Occiput is present anterior to the pubic bone of the right side of the mother's pelvis.

• Left occiput-posterior (LOP); Occiput is present posteriorly to the pubic bone of the left side of the mother's pelvis.
• Right, occiput-posterior (ROP); Occiput is present posteriorly to the pubic bone of the right side of the mother's pelvis.
• Left occiput transverse (LOT); Occiput is present in between anterior and posterior position on the left side of mother's pelvis. The babyfaces towards the right thigh of the mother.
• Right occiput transverse (ROT); Occiput is present in between anterior and posterior position on the left side of mother's pelvis. The babyfaces towards the left thigh of the mother.

Explanation:

Attitude	It refers to the relation of fetal parts to each other. It could be flexion and extension.
Lie	It refers to the relation of the fetal long axis to the mother's uterus long axis. There are three types: Longitudinal lie (same axis) Transverse lie (90-degree angle) Oblique lie (45-degree angle)
Station	It refers to the relation of the presenting part to the ischial spines. It is measured through vaginal examination where the fetus's skull is measured above or below the ischial spines.

Additional InformationThe denominator is a bony landmark on the presenting part. For example, the occiput is the denominator in the vertex position.