Commonest cause of non – engagement at term, in primi is:
**Core Concept**
The question is testing the understanding of the factors that contribute to non-engagement of the fetal head at term, particularly in primigravidas (primi). Non-engagement is a condition where the fetal head fails to move down into the pelvis, which can increase the risk of complications during labor. Contracted Pelvis Disease (CPD) is a condition where the maternal pelvis is abnormally small, leading to difficulty in fetal head engagement.
**Why the Correct Answer is Right**
The correct answer is CPD because it is a common cause of non-engagement in primigravidas. CPD can be due to various factors such as a small pelvic inlet, a narrow pelvic outlet, or a combination of both. In primigravidas, the fetal head is larger in proportion to the maternal pelvis, making it more difficult for the head to engage. The pelvis may not be able to accommodate the fetal head, leading to non-engagement. This condition can increase the risk of prolonged labor, fetal distress, and other complications.
**Why Each Wrong Option is Incorrect**
**Option B:** Hydramnios is a condition characterized by an excessive amount of amniotic fluid. While it can lead to complications during labor, it is not a direct cause of non-engagement of the fetal head at term.
**Option C:** Brow presentation is a type of fetal malpresentation where the brow of the fetus is presenting first. While it can cause difficulties during labor, it is not a common cause of non-engagement of the fetal head at term.
**Option D:** Breech presentation is a type of fetal malpresentation where the buttocks or feet are presenting first. While it can cause difficulties during labor, it is not a common cause of non-engagement of the fetal head at term.
**Clinical Pearl / High-Yield Fact**
In primigravidas, the risk of non-engagement of the fetal head at term is increased in cases of CPD. A careful assessment of the maternal pelvis and the fetal head size is essential to determine the risk of non-engagement and to plan for a safe delivery.
**✓ Correct Answer: A. CPD**