Expected weight of one-year old child, when the birth weight is 3.5 kg:

Appeared in: OSSSC Nursing Officer-2021

Explanation

According to standard pediatric growth milestones, an infant's birth weight is expected to triple by their first birthday.
Given a birth weight of 3.5 kg, the expected weight at one year is calculated by multiplying the birth weight by three.
This results in an expected weight of 10.5 kg (3.5 kg × 3 = 10.5 kg), making it the correct answer.

Option A: This weight represents the doubling of the birth weight (3.5 kg × 2 = 7 kg).
Option B: This weight is significantly below the expected weight for a one-year-old and does not correspond to any standard growth milestone for a child with a 3.5 kg birth weight.
Option C: While closer to the correct weight, 9.5 kg is still below the expected tripling of birth weight by one year.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Infant growth milestones: weight gain as background academic context rather than a clinical decision trigger.
Nurses use these weight milestones during well-child visits to assess growth, nutritional status, and overall health. Plotting weight on a growth chart is a fundamental nursing assessment.
Failure to meet these milestones can be an early indicator of 'failure to thrive,' feeding problems, or other underlying health issues, requiring further investigation and intervention.
What if? If the question asked for the expected weight at 2 years, the answer would be quadruple the birth weight (3.5 kg × 4 = 14 kg). This demonstrates the importance of knowing milestones for different age groups.

How to Approach the Question

First, identify the key information provided in the question: the child's age (one year) and the birth weight (3.5 kg).
The question asks for the 'expected weight,' which requires recalling a standard pediatric growth milestone.
Recall the rule for weight gain at one year: an infant's birth weight typically triples.
Apply this rule by performing the calculation: multiply the birth weight (3.5 kg) by 3.
The result is 10.5 kg. Compare this calculated value with the given options to find the correct answer.

Concept Tested & Keywords

Concept Tested: Infant growth milestones: weight gain
Stem keywords: Expected weight, one-year old child, birth weight, 3.5 kg
Lead-in keywords: Expected weight
Clinical cues: Age/sex group narrows the expected diagnosis, intervention, or normal reference range.
Negative lead-in flag: false

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E6 Ghai Essential Pediatrics(pp 26-904 of 913) p. 10-12

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