Why does the CDC recommend WHO growth standards for children under 2?

The World Health Organization (WHO) growth charts are based on healthy infants raised in optimal conditions (primarily breastfed). They reflect how infants grow under ideal conditions, making them the gold standard worldwide.

How much weight should a newborn gain per week?

After regaining birth weight by 10 to 14 days, a healthy infant typically gains 5 to 7 ounces (140 to 200 grams) per week during the first 3 months, and about 3 to 5 ounces per week from 3 to 6 months.

When should I be concerned about my baby’s growth curve?

Pediatricians monitor for sudden crossing of two or more major percentile lines (e.g., dropping from the 75th to the 25th percentile) or a flattening curve over consecutive checkups.

WHO Pediatric Standards

Baby Growth Percentiles & WHO Growth Charts Explained

Learn how pediatricians use World Health Organization (WHO) growth charts to track weight, length, and head circumference curves from 0 to 24 months.

Typical Infant Weight Gain Velocity

Age Stage	Weekly Weight Gain	Monthly Weight Gain	Milestone Benchmark
0–2 Weeks	Weight loss initially (up to 7–10%)	Regain birth weight by day 10–14	Return to birth weight
2 Weeks – 3 Months	5–7 oz (140–200 g)	1.5–2.0 lbs (680–900 g)	Rapid growth spurt phase
4–6 Months	3–5 oz (85–140 g)	1.0–1.25 lbs (450–560 g)	Double birth weight by 5–6 mo
6–12 Months	2–3 oz (55–85 g)	0.5–1.0 lb (225–450 g)	Triple birth weight by 1 year

What Does "Staying on the Curve" Mean?

A baby born in the 15th percentile who consistently gains weight along the 15th percentile curve is just as healthy as a baby in the 85th percentile. The percentile is a marker of size, not a grade of health.

Consistency

Tracking regular pediatric checkups creates a continuous trendline that proves steady nourishment.

Head Circumference

Measures brain and cranial growth—equally as critical as length and weight during the first 2 years.

Growth Spurts

Temporary surges occur at 3 weeks, 6 weeks, 3 months, and 6 months with increased feeding demand.

Frequently Asked Questions About Baby Growth

A percentile indicates where your baby ranks compared to a standard population of healthy babies of the same age and sex. For example, if your baby is in the 60th percentile for weight, it means they weigh more than 60% of babies and less than 40%. A higher percentile is not "better"—consistency along their own individual curve is what matters.

Plot your baby's WHO growth curves in Tummy

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