Deep transverse arrest is complication of?

VSSC Nursing Officer - 2021

Obstetrics & Gynaecology

Medium

Appeared in: VSSC Nursing Officer - 2021

Explanation

Deep transverse arrest (DTA) is a specific type of obstructed labor where the fetal head gets stuck in the transverse diameter deep within the maternal pelvis.
This occurs due to a failure of internal rotation, a crucial movement the fetal head must make to navigate the birth canal.
This failure of rotation is most commonly associated with a persistent occipito-posterior (OP) position, where the fetus starts with its occiput facing the mother's back.
In an OP position, the head must undergo a long 135-degree rotation. If it only rotates 90 degrees to an occiput-transverse (OT) position and then stops, DTA occurs.
Factors like an android or platypelloid pelvic shape, or inefficient uterine contractions, can contribute to this failure of rotation.

Option A: This is the ideal and most favorable position for vaginal delivery. The head is already aligned for easy passage, making arrest unlikely.
Option B: Vertex presentation simply means the baby is head-down. While DTA occurs in a vertex presentation, this term is too general. The complication arises from a specific malposition (OP) within the vertex presentation, not the presentation itself.
Option C: Breech presentation means the baby is positioned feet or buttocks first. Deep transverse arrest is a complication related to the arrest of the fetal head in a cephalic (head-first) presentation.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Complications of Fetal Malposition during Labor as background academic context rather than a clinical decision trigger.
Recognizing the risk factors for DTA, such as a persistent OP position and prolonged second-stage of labor, is a critical nursing skill.
Nurses play a key role in monitoring labor progress using a partograph, identifying lack of descent and rotation, and alerting the obstetrician.
Nursing interventions may include encouraging maternal position changes (e.g., hands and knees, lunging) to facilitate fetal rotation.

How to Approach the Question

First, define the term in the question stem: 'Deep transverse arrest' is an arrest of labor where the fetal head is stuck in a transverse position deep in the pelvis.
Recall the normal mechanism of labor. The fetal head typically enters the pelvis in a transverse position and must rotate to an anterior position to pass through the outlet.
Understand that 'arrest' implies a failure of this normal process, specifically a failure of internal rotation.
Evaluate each option: A) Occipito-anterior is the normal, desired outcome. B) Vertex presentation is too general. C) Breech is the wrong presentation.
Identify which option represents a malposition known to cause difficult or failed rotation. The occipito-posterior position requires the longest rotation (135 degrees), making it the most likely cause of rotational failure and subsequent arrest in a transverse position.

Concept Tested & Keywords

QB3sQksJN6mLHJVBiMOYCe

E6 Obstetrics Williams pp. 39-57, 19-36