An infant whose weight falls between the 10th and 90th percentile on intrauterine growth curves comes under the classification of:

Appeared in: BTSC Staff Nurse 1 August-2025

Explanation

An infant whose weight is between the 10th and 90th percentile for their gestational age is classified as Appropriate for Gestational Age (AGA).
This classification signifies that the infant has demonstrated normal, expected growth in utero.
AGA is the standard benchmark for assessing a newborn's size relative to the duration of the pregnancy.
Infants classified as AGA typically have the lowest risk of neonatal morbidity and mortality related to size.

Option B: Small for Gestational Age (SGA) is the classification for infants with a birth weight below the 10th percentile, not between the 10th and 90th.
Option C: Intrauterine Growth Restriction (IUGR) is a prenatal diagnosis describing a pathological process where the fetus fails to achieve its growth potential. It is a cause, not the resulting classification based on percentile at birth. Many, but not all, IUGR infants are born SGA.
Option D: Large for Gestational Age (LGA) is the classification for infants with a birth weight above the 90th percentile.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Classification of newborn weight based on gestational age percentiles as background academic context rather than a clinical decision trigger.
Nurses use these growth classifications to anticipate and screen for potential neonatal complications. This initial assessment guides the plan of care.
SGA infants are at higher risk for hypoglycemia, hypothermia, and polycythemia, requiring close monitoring of blood sugar and temperature.
LGA infants, often born to diabetic mothers, are at risk for birth trauma (e.g., shoulder dystocia), hypoglycemia, and respiratory distress.

How to Approach the Question

This is a factual recall question that tests your knowledge of standard neonatal classifications.
First, identify the key data point in the question stem: 'weight falls between the 10th and 90th percentile'.
Next, recall the definitions for the three main newborn growth classifications: Small for Gestational Age (SGA), Appropriate for Gestational Age (AGA), and Large for Gestational Age (LGA).
Match the given percentile range (10th-90th) to the correct term, which is 'Appropriate for Gestational Age'.
Eliminate the other options by defining their specific percentile cutoffs: SGA is less than the 10th, and LGA is greater than the 90th.
Differentiate AGA from IUGR by remembering that IUGR is a diagnosis of a pathological growth process, not simply a measurement classification at birth.

Concept Tested & Keywords

Concept Tested: Classification of newborn weight based on gestational age percentiles.
Stem keywords: infant, weight, 10th and 90th percentile, intrauterine growth curves, classification
Lead-in keywords: comes under the classification of
Clinical cues: Age/sex group narrows the expected diagnosis, intervention, or normal reference range.
Negative lead-in flag: false

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E6 Nelson Textbook of Pediatrics(2024) — Volume 1 p. 1056-1058

E6 Midwifery Obstetrics and Gynecology Nursing Sandeep Kaur p. 8-13

Practise the full BTSC Staff Nurse 1 August-2025

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