Many scan reports in India show an estimated fetal weight (EFW) in grams. It is natural to compare that number with a chart and worry if it looks low or high. This article explains how to read it calmly.
What is a percentile?
A percentile compares your baby with other babies at the same week of pregnancy. If your baby is on the 50th percentile, half of babies are smaller and half are bigger. The 30th or 70th are also very ordinary. Most healthy babies fall between roughly the 10th and 90th percentile.
Why the number is an estimate
The scan does not weigh the baby. The machine measures the head, tummy and thigh bone, and a formula turns those into a weight. The result can be off by a good margin, so one number is never the whole story. Your doctor looks at several scans over time to see how your baby is growing.
Where our reference comes from
Our checker uses the INTERGROWTH-21st standards (University of Oxford, published in 2016), which describe how babies grow in healthy pregnancies across several countries. It covers weeks 22 to 40.
What the ranges mean
- Typical range: where most babies sit. Higher or lower inside this range is normal.
- Smaller or bigger side: often family build or a date that is a few days off. Usually watched with repeat scans.
- Much smaller or much bigger than most: worth seeing your obstetrician soon to go over the scan. This is not always a problem, but it should be looked at properly.
When to call your doctor the same day
Call your doctor or go to the hospital if your baby is moving less than usual, or if you have bleeding, leaking fluid, severe tummy pain or a severe headache.
Try it with your own report: Is my baby's weight okay?