Untwisting of the neck sustained during internal rotation is called as?

JODHPUR AIIMS SNO-2018

Obstetrics & Gynaecology

Easy

Appeared in: JODHPUR AIIMS SNO-2018

Explanation

Restitution is the correct term for the untwisting of the fetal neck that occurs after the head is delivered.
This movement is a passive correction of the torsion (twist) that the neck undergoes during the process of internal rotation.
During internal rotation, the head turns to align with the pelvic outlet, but the shoulders do not, creating a twist.
Once the head is free, it spontaneously rotates back (restitutes) to align with the shoulders, which are still inside the birth canal.
This realignment is crucial for the subsequent delivery of the shoulders (external rotation and expulsion).

Option A: Crowning is a milestone in the second stage of labor, not a fetal movement. It describes the point when the fetal head is visible at the vaginal opening and no longer recedes between contractions.
Option B: Flexion is an early cardinal movement where the fetal chin tucks to its chest. This action reduces the presenting diameter of the head, facilitating its descent into the pelvis. It occurs before internal rotation and delivery of the head.
Option D: Torsion is a general term for the act of twisting. While the neck does experience torsion during internal rotation, the question asks for the name of the untwisting movement. Restitution is the specific, correct obstetrical term for this corrective action.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Cardinal Movements of Labor as background academic context rather than a clinical decision trigger.
Understanding the cardinal movements of labor is fundamental for nurses and midwives to monitor labor progress and identify abnormalities (dystocia).
The observation of restitution is a reassuring sign that the fetus is correctly aligning for the delivery of the shoulders.
What if? If restitution does not occur after the head is delivered, it may signal a problem like shoulder dystocia, where the anterior shoulder is impacted behind the pubic symphysis. This is an obstetric emergency requiring immediate and specific maneuvers to release the shoulder and prevent fetal injury.

How to Approach the Question

First, identify the key action described in the question: the "untwisting of the neck."
Next, recall the sequence of events in the mechanism of labor (the cardinal movements).
Remember that during internal rotation, the fetal head turns to pass through the pelvis, but the shoulders stay in a different orientation. This creates a twist, or torsion, in the neck.
The question asks for the term that describes the correction of this twist after the head is born.
Evaluate the options: 'Crowning' and 'Flexion' are distinct, separate events in labor. 'Torsion' describes the twist itself, not the correction.
'Restitution' specifically refers to the passive untwisting of the head to realign with the shoulders. Therefore, it is the correct answer.

Concept Tested & Keywords

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