Inobstetrics,position is the orientation of thefetus in thewomb, identified by the location of thepresenting part of the fetus relative to thepelvis of the mother. Conventionally, it is the position assumed by the fetus before the process of birth, as the fetus assumes various positions and postures during the course ofchildbirth.
Depending upon which part of the fetus is expected to be delivered first (fetal presentation), there are many possible positions:
| Name | Abb. | Description |
|---|---|---|
| Left occipitoanterior | LOA | occiput,[note 1] 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 | occiput faces anteriorly and towards right. Less common than LOA, but not associated with labor complications. |
| Left occipitoposterior | occiput faces posteriorly (behind) and towards left. | |
| Right occipitoposterior | ROP | occiput faces posteriorly and towards right. |
| Occipitoanterior | occiput faces anteriorly (absolutely straight without any turning to any of the sides) | |
| Occipitoposterior | occiput faces posteriorly (absolutely straight without any turning to any of the sides) | |
| Left occipitotransverse | LOT | occiput faces left |
| Right occipitotransverse | ROT | occiput faces right |