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Fetal Percentile Calculator – Baby Growth Chart

Calculate fetal weight percentile by gestational age

This calculator provides estimates. Actual fetal growth should be monitored by healthcare professionals through regular ultrasound examinations.
Calculate Percentile

How to Use

  1. Enter gestational age in weeks
  2. Enter current fetal weight
  3. Select weight unit (grams or pounds)
  4. Click calculate to see the percentile

What is Fetal Percentile?

Fetal percentile indicates how your baby's weight compares to other babies at the same gestational age. The 50th percentile represents the average, while higher or lower percentiles indicate above or below average size.

Understanding Percentiles

  • 10th percentile or below: Small for gestational age (SGA)
  • 10th-90th percentile: Average for gestational age (AGA)
  • 90th percentile or above: Large for gestational age (LGA)
  • Most babies between 10th-90th percentile are healthy
  • Extreme percentiles may warrant additional monitoring

Factors Affecting Fetal Size

  • Genetics and parental size
  • Maternal nutrition and health
  • Placental function
  • Multiple pregnancy (twins, triplets)
  • Gestational diabetes
  • Maternal smoking or substance use

Frequently Asked Questions

What does it mean if my baby is in a low percentile?
A lower percentile (below 10th) may indicate small for gestational age. However, some babies are naturally smaller. Your healthcare provider will monitor growth trends and check for any underlying issues.
Is a high percentile concerning?
A high percentile (above 90th) indicates a larger baby. This can be normal, especially if parents are large, but may also be associated with gestational diabetes. Your doctor will provide appropriate guidance.
How often should fetal weight be checked?
Routine ultrasounds typically check fetal weight in the second and third trimesters. More frequent monitoring may be recommended if there are concerns about growth.

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