Most common position of is LOA in normal labour ?
Reading File
Finding Sources
Finding Sources
Finding Sources
Finding Sources
Finding Sources
Reading File
The textbook source confirms this clearly. Here is a complete answer:
Most Common Fetal Position in Normal Labour: LOA (Left Occiput Anterior)
LOA - Left Occiput Anterior is the most common position of the fetal head in normal labour and the most common intrauterine position overall.
Definition
- The occiput (presenting part in vertex presentation) points toward the left iliopectineal eminence of the maternal pelvis
- The sagittal suture lies in the right oblique diameter of the pelvis
- The face is directed toward the right sacroiliac joint
Why LOA is Most Common
The left oblique diameter of the pelvis is slightly more accommodating due to the position of the sigmoid colon on the left, which "pushes" the fetal head toward the LOA position. The fetus naturally adopts this position as the path of least resistance.
Clinical Significance
- As confirmed in Campbell's Operative Orthopaedics (15th Ed, 2026), LOA is explicitly called "the most common intrauterine position," and this is why DDH (Developmental Dysplasia of the Hip) is more common in the left hip - because in LOA, the left hip of the fetus is pressed in an adducted position against the maternal lumbosacral spine.
Summary of Positions by Frequency
| Position | Frequency |
|---|---|
| LOA (Left Occiput Anterior) | Most common (~40%) |
| ROA (Right Occiput Anterior) | Second most common |
| LOP / ROP (Occiput Posterior) | Less common |
| LOT / ROT (Occiput Transverse) | Intermediate |
Key Exam Point
LOA = Most common position in normal labour Sagittal suture in right oblique diameter, occiput to the left and anterior.
- Campbell's Operative Orthopaedics, 15th Ed, p. 4233-4234
This is a shared conversation. Sign in to Orris to start your own chat.