What is the expected head circumference of the child at the age of one year?

RUHS, Jaipur, PB B.Sc Nursing Entrance-2020

Child Health Nursing (Pediatrics)

Easy

Appeared in: RUHS, Jaipur, PB B.Sc Nursing Entrance-2020

Explanation

The average head circumference for a child at one year of age is approximately 45-47 cm.
This rapid growth during the first year is a direct reflection of brain development.
At around one year of age, a key developmental milestone is when the head circumference becomes equal to the chest circumference.
After one year, the chest continues to grow more rapidly than the head.

Option A: A head circumference of 25 cm is abnormally small for a one-year-old and is a sign of severe microcephaly, indicating impaired brain growth.
Option B: A head circumference of 35 cm is the expected average for a full-term newborn infant, not a one-year-old.
Option D: A head circumference of 55 cm is far too large for a one-year-old and is closer to an adult measurement. In a child, this would suggest macrocephaly or hydrocephalus.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Normal pediatric growth parameters, specifically head circumference milestones as background academic context rather than a clinical decision trigger.
Monitoring head circumference is a critical nursing responsibility in pediatric care as it provides a non-invasive way to assess brain growth and neurological development.
Deviations from the normal growth curve (either too small, microcephaly, or too large, macrocephaly) can be the first sign of a serious underlying medical condition, prompting the need for further investigation.
What if? If a 9-month-old infant's head circumference has crossed two percentile lines upwards on the growth chart, the nurse should suspect rapidly increasing intracranial pressure (e.g., hydrocephalus) and report it to the physician immediately for further evaluation.

How to Approach the Question

First, identify the key parameters in the question: the measurement required (head circumference) and the specific age (one year).
This is a factual recall question that relies on knowledge of normal pediatric growth milestones.
Recall the average head circumference at birth (around 33-35 cm) and the expected growth pattern in the first year.
Remember the key milestone that at one year, the head circumference is about 45 cm and equals the chest circumference.
Evaluate the given options against this knowledge. 35 cm is the birth size, 25 cm is too small (microcephaly), and 55 cm is too large (macrocephaly).
Select the option that matches the expected value for a one-year-old.

Concept Tested & Keywords

Concept Tested: Normal pediatric growth parameters, specifically head circumference milestones.
Stem keywords: head circumference, child, one year
Lead-in keywords: expected
Clinical cues: Age/sex group narrows the expected diagnosis, intervention, or normal reference range.

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