At one year of age, what may be the expected weight and length of a normal full-term baby with a birthweight of 3 kg and length of 50 cm?

1. A

   6 kg and 50 cm

2. B

   9 kg and 75 cm

3. C

   12 kg and 80 cm

4. D

   6 kg and 75 cm

Appeared in: DSSSB 12 August 2024

Explanation

• A normal infant's birth weight typically triples by the end of the first year.
• For a baby with a birth weight of 3 kg, the expected weight at one year is approximately 9 kg (3 kg × 3).
• An infant's birth length increases by about 50% by the first year.
• With a birth length of 50 cm, the expected length at one year is approximately 75 cm (50 cm + 25 cm).

Why Other Options Were Wrong

• Option A: 6 kg is the expected weight around 5-6 months when the birth weight doubles, and 50 cm is the birth length, indicating no growth in length.
• Option C: 12 kg is the expected weight at 2 years of age (when birth weight quadruples), and 80 cm is the average length for a child around 18 months old.
• Option D: While 75 cm is the correct expected length for a one-year-old, 6 kg is the expected weight for a 5-6 month old infant.

Related Visual

Clinical Relevance

• Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Normal infant growth parameters (weight and length) at one year as background academic context rather than a clinical decision trigger.
• Monitoring growth is a fundamental part of pediatric nursing care to assess nutritional status and overall health. Deviations from the expected curve can be the first sign of underlying health issues.
• What if? If the same baby weighed only 7 kg at one year, this would be classified as 'underweight' and may indicate failure to thrive, prompting a detailed nutritional assessment and investigation into potential feeding problems or organic disease.

How to Approach the Question

• First, identify the key information given: the baby's age (one year), birth weight (3 kg), and birth length (50 cm).
• Recall the standard rules for infant growth in the first year.
• Apply the rule for weight: birth weight triples by one year. Calculate 3 kg * 3 = 9 kg.
• Apply the rule for length: birth length increases by 50% (or to about 75 cm) by one year. Calculate 50 cm + (50% of 50) = 75 cm.
• Compare your calculated values (9 kg and 75 cm) with the given options to find the correct match.

Concept Tested & Keywords

• Concept Tested: Normal infant growth parameters (weight and length) at one year.
• Stem keywords: one year of age, expected weight, expected length, normal full-term baby, birthweight 3 kg, length 50 cm
• Lead-in keywords: what may be
• Negative lead-in flag: false

Question ID

QwWWjE65pPl5SfQq6k5vHI

Copy ID

Reference Book

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