Fetal Growth Percentile Calculator

The Fetal Growth Percentile Calculator estimates your baby's growth percentile based on ultrasound measurements like estimated fetal weight, head circumference, and femur length. This tool helps expectant parents and healthcare providers track fetal development to ensure the baby is growing correctly. Whether you are monitoring for small for gestational age (SGA), checking for large for gestational age (LGA), or confirming healthy progress, this calculator provides clear, data-driven insights.

Enter the gestational age in weeks (e.g., 24.5 for 24 weeks and 5 days)
Enter the estimated fetal weight in grams from ultrasound
Enter the femur length measurement in millimeters
Enter the abdominal circumference measurement in millimeters
Enter the biparietal diameter measurement in millimeters
Enter the head circumference measurement in millimeters

How Average Fetal Growth Percentile Is Calculated

The Average Fetal Growth Percentile represents how your baby's size compares to a standardized population of healthy babies at the same gestational age and sex. Instead of relying on a single number, this tool uses a method that compares multiple biometric measurements against established medical growth charts.

  1. First, you input specific ultrasound data, such as abdominal circumference, head circumference, and femur length, along with the gestational age.
  2. The calculator then compares each of these measurements to standard reference values based on the fetal gender.
  3. It converts these raw numbers into individual percentiles and derives a composite average score to represent overall growth.

Using these specific growth standards ensures that the result is accurate and accounts for natural variations in development.

What Your Average Fetal Growth Percentile Means

This percentile score tells you what percentage of babies your fetus is larger or smaller than at this specific stage of pregnancy. For example, a result of 50 means your baby is right in the middle of the size range, while higher or lower numbers indicate size differences relative to the average population.

Growth Categories

Small for Gestational Age (SGA): Below the 10th percentile. Your doctor may monitor for growth restriction to ensure the baby receives enough nutrients.

Appropriate for Gestational Age (AGA): Between the 10th and 90th percentiles. This indicates normal growth, and routine prenatal care is usually all that is needed.

Large for Gestational Age (LGA): Above the 90th percentile. This may prompt checks for gestational diabetes or planning for a safer delivery.

Important: Percentiles are just one part of the picture. Genetics and parental size also play a major role in how big a baby will be.

This tool is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your healthcare provider with any questions regarding fetal health or pregnancy conditions.

For the best results, compare your current percentile with previous scans to track the growth trend over time rather than focusing on a single result.

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