Fetal tachycardia is caused due to all of the following factors except

Appeared in: NHM UP Staff Nurse-2021 Shift-1st

Explanation

Severe fetal hypoxia is the correct exception because it leads to fetal bradycardia, not tachycardia.
While early or mild hypoxia can cause a compensatory tachycardia, severe and prolonged oxygen deprivation depresses the fetal heart muscle (myocardium).
This myocardial depression, combined with increased parasympathetic (vagal) nerve stimulation, results in a significant slowing of the fetal heart rate, defined as bradycardia (less than 110 bpm).
Therefore, severe hypoxia is associated with a decreased heart rate, making it the factor that does not cause tachycardia.

Option A: Maternal or fetal anemia is a well-established cause of fetal tachycardia.
Option B: Maternal or fetal infection is a common cause of fetal tachycardia.
Option D: Fetal compromise or distress often initially presents as tachycardia.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Causes of Fetal Tachycardia as background academic context rather than a clinical decision trigger.
Recognizing the cause of fetal tachycardia is critical for timely intervention. While often compensatory, persistent tachycardia can indicate an underlying problem like infection or hypoxia that requires immediate attention.
A key nursing responsibility is to differentiate between the causes. For example, if maternal fever is present, infection is likely. If not, other causes like anemia, dehydration, or medication effects must be considered.
A change from tachycardia to bradycardia is an ominous sign, indicating the fetus is no longer able to compensate and is decompensating, often due to severe hypoxia. This requires emergency intervention.

How to Approach the Question

First, identify the core concept: causes of fetal tachycardia. The keyword 'except' is crucial, meaning you must find the option that is NOT a cause.
Define fetal tachycardia in your mind: a baseline FHR greater than 160 bpm.
Evaluate each option to see if it causes an increase in fetal heart rate.
Option A (Anemia): Recall that anemia means less oxygen-carrying capacity. The heart compensates by beating faster. So, this causes tachycardia.
Option B (Infection): Recall that infection/fever increases metabolic demand, which increases heart rate. So, this causes tachycardia.
Option D (Fetal compromise): Recall that tachycardia is an early compensatory response to stress. So, this is associated with tachycardia.

Concept Tested & Keywords

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E6 Obstetrics Williams p. 56-75

E6 Nursing Fundamentals Taylor p. 124-126

Practise the full NHM UP Staff Nurse-2021 Shift-1st

Attempt every question from this paper in a timed mock, then review the full solution for each one.