Growth
Weight in the first weeks, and what percentiles mean
When to get help: fever, breathing, feeding and other warning signs. In an emergency, call your local emergency number.
The first weeks
- Most babies lose some weight after birth (often up to 7 to 10%) and are back to their birth weight by 10 to 14 days.
- After that, babies typically gain about 150 to 200 g (5 to 7 oz) a week for the first few months.
- Many babies double their birth weight by about 4 to 6 months and triple it by 1 year.
Percentiles
- A percentile compares your baby with healthy babies of the same age and sex. On the 30th percentile, 30 in 100 babies weigh less.
- There is no “best” percentile. What matters is growing steadily along a curve. Your doctor watches for big jumps up or down across the lines.
- This app uses the World Health Organization growth standards, also used by doctors for babies under 2.
Measuring at home
- Home scales and tape measures vary. Use the same scale, at the same time of day, with your baby undressed. Your doctor’s measurements are the ones to rely on.
Sources
- World Health Organization
- U.S. Centers for Disease Control and Prevention
- American Academy of Pediatrics (HealthyChildren.org)
General information for most babies, not medical advice. Your doctor, nurse or midwife knows your baby: always ask them, and call your local emergency number in an emergency.