An infant has a 3 kg weight at birth. What is the expected weight after 1 year?

Appeared in: AIIMS Delhi NO - 2017

Explanation

A key milestone in infant development is that they typically triple their birth weight by their first birthday.
For an infant with a birth weight of 3 kg, the expected weight at 1 year is calculated as 3 kg × 3, which equals 9 kg.
This rule of thumb is a standard part of pediatric growth assessment.
Infants are also expected to double their birth weight by approximately 5 to 6 months of age.

Option B: A weight of 8 kg is below the expected tripling of the 3 kg birth weight. It suggests a slightly slower than average growth rate.
Option C: A weight of 10 kg is more than the expected tripling of birth weight. This weight is closer to the median weight for an infant around 15 months of age.
Option D: This is the infant's weight at birth. A weight of 3 kg at 1 year would indicate a complete lack of growth, a serious condition known as 'failure to thrive' that requires immediate medical investigation.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Infant growth milestones, specifically weight gain in the first year of life as background academic context rather than a clinical decision trigger.
Monitoring an infant's weight is a fundamental nursing responsibility to assess growth, nutritional status, and overall health.
Significant deviations from expected weight milestones can be an early indicator of underlying health issues, such as feeding problems, metabolic disorders, or illness.
What if? If the same infant weighed only 6 kg at 1 year, this would represent a doubling, not tripling, of birth weight. This finding would be a significant concern for 'failure to thrive' and would require immediate nursing assessment, nutritional counseling, and medical evaluation.

How to Approach the Question

First, identify the key data provided in the question: the infant's birth weight (3 kg) and the age for which the weight is being asked (1 year).
Recall the standard rule for infant weight gain during the first year of life.
The key milestone is that an infant's weight typically triples by the age of one year.
Apply this rule to the given birth weight: 3 kg × 3 = 9 kg.
Compare the calculated result with the given options and select the matching value.

Concept Tested & Keywords

Concept Tested: Infant growth milestones, specifically weight gain in the first year of life.
Stem keywords: infant, 3 kg weight, birth, expected weight, 1 year
Lead-in keywords: What is
Clinical cues: Age/sex group narrows the expected diagnosis, intervention, or normal reference range.

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

E6 Nutrition Kumud Khanna 2e p. 109-111

Practise the full AIIMS Delhi NO - 2017

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