Vertex position of foetus means
A. Head is toward fundus of uterus B. Head is unstable C. Head is toward mother’s pelvis D. Foetus is oblique is uterus
Correct Answer: C. Head is toward mother’s pelvis
Explanation
Vertex position of the fetus means:
👉 The fetal head is presenting, and the occiput (back of the head) is the presenting part in the birth canal.
Explanation
- Vertex refers to the area of the fetal skull between the anterior and posterior fontanelles.
- In vertex presentation, the head is well-flexed, so the occiput leads during labour.
- The long axis of the fetus is parallel to the long axis of the uterus (longitudinal lie).
- This allows the smallest anteroposterior diameter of the head (suboccipito-bregmatic, ~9.5 cm) to engage in the pelvis.
Key points
- ✔ Most common and normal fetal presentation
- ✔ Most favourable for vaginal delivery
- ✔ Accounts for about 95% of term deliveries
Simple definition (exam-friendly)
Vertex position means the fetal head presents with the occiput as the leading part due to good flexion of the head.
Other Options Details
These options describe different fetal lies/presentations in the uterus. I’ll explain each option clearly and also mention whether it is normal or abnormal.
A. Head is toward fundus of uterus
- This means the fetal head is in the upper part of the uterus (fundus).
- The buttocks or feet are toward the pelvis.
- This is called Breech presentation.
- ❌ Not the normal presentation for vaginal delivery.
- Breech may cause difficult or assisted delivery.
B. Head is unstable
- The fetal head is not fixed in the pelvis.
- It moves freely above the pelvic inlet.
- Seen in:
- Multiparous women
- Excess liquor (polyhydramnios)
- Prematurity
- ❌ Risk of cord prolapse if membranes rupture.
- Called unstable lie.
C. Head is toward mother’s pelvis
- The fetal head is downward toward the pelvis.
- This is called Cephalic (Vertex) presentation.
- ✅ Most common and most favourable for normal vaginal delivery.
- Normal presentation in about 95% of pregnancies at term.
D. Foetus is oblique in uterus
- The fetus lies diagonally in the uterus.
- Neither longitudinal nor transverse.
- This is called Oblique lie.
- ❌ Abnormal lie.
- May convert to longitudinal lie before labour, but if persists → risk of complications.
Summary Table
Option Condition Normal/Abnormal A Breech presentation ❌ Abnormal B Unstable lie ❌ Abnormal C Vertex presentation ✅ Normal D Oblique lie ❌ Abnormal
I hope that you liked this article.
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Writer: Vandita Singh, Lucknow (GS India Nursing Group