of the fetus in Obstetrics
refers to the orientation
of the presenting part
with the pelvis
of the mother. Conventionally, it is the position assumed by the fetus before the process of birth as during the course of childbirth
, the fetus assumes various positions and postures.
Depending upon which part of the fetus is expected to be delivered first (fetal presentation), there are many possible positions:
- Vertex presentation with longitudinal lie:
- Left occipitoanterior (LOA)—the occiput, as against the buttocks, is close to the vagina (hence known as vertex presentation) faces anteriorly (forward with mother standing) and towards left. This is the most common position and lie.
- Right occipitoanterior (ROA)—the occiput faces anteriorly and towards right. Less common than LOA, but not associated with labor complications.
- Left occipitoposterior (LOP)—the occiput faces posteriorly (behind) and towards left.
- Right occipitoposterior (ROP)—the occiput faces posteriorly and towards right.
- Occipitoanterior—the occiput faces anteriorly (absolutely straight without any turning to any of the sides)
- Breech presentation with longitudinal lie:
- Left sacrum anterior (LSA)—the buttocks, as against the occiput of the vertex presentation, like close to the vagina (hence known as breech presentation), which like anteriorly and towards the left.
- Right sacrum anterior (RSA)—the buttocks face anteriorly and towards the right.
- Left sacrum posterior (LSP)—the buttocks face posteriorly and towards the left.
- Right sacrum posterior (RSP)—the buttocks face posteriorly and towards right.
- Sacrum anterior (SA)—the buttocks face anteriorly.
- Sacrum posterior (SP)—the buttocks face posteriorly.
Normal Labor and Delivery from Management of Labor and Delivery provided by Google books