GROWTH & DEVELOPMENT
What does your baby’s next step look like?
A growth chart gives you numbers. A play mat shows you new attempts. A fussy week may leave you wondering whether something is changing. These articles help you look at each question without trying to fit every baby to the same calendar.
Prepared by Nerumi · Sources checked September 23, 2026
What does that percentile actually mean?
It’s tempting to read a higher number as a better result. Start with how growth charts work, then look at the pattern your pediatrician sees across several measurements.
How to read your baby's growth percentiles
Understand percentiles, measurement differences, and why weight, length, and head circumference are considered together.
Learn to read a growth chartIf you’re comparing today’s weight with birth weight, there’s a more specific question to explore next.
When Do Babies Double Their Birth Weight?
What does doubling birth weight tell you—and what does it leave out? See how U.S. pediatricians assess growth in context.
Put birth-weight doubling in contextMore feeding, more fussing: is it a growth spurt?
A difficult few days can make a growth-spurt explanation sound convincing. This article looks at what you can observe and what those observations cannot confirm by themselves.
Baby growth spurts: what can you actually tell?
Explore the difference between a measured growth pattern and a prediction from a popular leap calendar.
Make sense of growth-spurt claimsEveryone mentions an “8-week leap.” What should I look for?
If your baby’s feeds, sleep, and alert periods all seem different, you don’t need to solve everything with one label. Start with the changes you’re seeing around two months.
Is There Really an 8-Week Leap or 2-Month Growth Spurt?
A U.S. guide to the questions behind the “8-week leap”: changing behavior, feeding concerns, and what to bring up at the next visit.
Look beyond the leap labelShould my 6-month-old be sitting or crawling?
Watching another baby sit or move can make you question your own baby’s progress. Look at what the milestone lists describe and how to talk about the skills you’re seeing.
Should a 6-Month-Old Be Sitting Up or Crawling?
Explore supported sitting, independent sitting, and movement development using U.S. milestone resources, including when to raise a concern.
Explore sitting and crawling questionsTake your observations to the next visit
The 2-, 4-, and 6-month well-child visit guide explains how development fits into routine care. You can also explore the U.S. 6-month baby guide.
If your baby has lost a skill or you’re concerned about development, contact your pediatrician rather than waiting for the next routine appointment. A checklist can help you describe a concern; it cannot diagnose a delay.
Sources and official guidance
These U.S. resources support the topics on this page. Each linked article includes sources for its detailed guidance.
- CDC — Developmental Milestones: Age-specific checklists and guidance on discussing concerns.
- CDC — Using WHO Child Growth Standards: How WHO growth standards are used in U.S. infant care.