Small Gestational Age Calculator

Small Gestational Age Formula:

\[ SGA = Birth\ Weight < 10^{th}\ Percentile\ for\ Gestational\ Age \]

Small for Gestational Age (SGA):

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1. What is Small for Gestational Age?

A newborn is considered Small for Gestational Age (SGA) when their birth weight is below the 10th percentile for their gestational age. This indicates the baby is smaller than 90% of babies born at the same gestational week.

2. How Does the Calculator Work?

The calculator uses a simple comparison:

\[ SGA = Birth\ Weight < 10^{th}\ Percentile\ for\ Gestational\ Age \]

Where:

\( Birth\ Weight \) — Measured weight of the newborn in kilograms
\( 10^{th}\ Percentile \) — The weight threshold for the 10th percentile at the given gestational age

Explanation: The calculator compares the actual birth weight against standard growth charts to determine if the baby falls below the 10th percentile for their gestational age.

3. Importance of SGA Determination

Details: Identifying SGA infants is crucial as they may be at higher risk for complications including hypoglycemia, polycythemia, and long-term growth and developmental issues.

4. Using the Calculator

Tips: Enter the baby's birth weight in kilograms and the 10th percentile weight for their gestational age (from standard growth charts). Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between SGA and IUGR?
A: SGA refers to size (weight below 10th percentile), while Intrauterine Growth Restriction (IUGR) refers to a fetus that hasn't reached its growth potential, often due to placental insufficiency.

Q2: What gestational age charts should I use?
A: Use population-specific growth charts when available. Common references include Fenton, INTERGROWTH-21st, or WHO growth standards.

Q3: Are all SGA babies unhealthy?
A: Not necessarily. Some are constitutionally small but healthy. However, SGA babies require closer monitoring for potential complications.

Q4: What follow-up is needed for SGA infants?
A: Typically includes monitoring for catch-up growth, developmental assessments, and screening for metabolic complications.

Q5: Can SGA be prevented?
A: Some risk factors (like smoking) are modifiable, but many causes (like placental insufficiency) may not be preventable.