Baby Weight Gain and Milestones in the First Year

Most healthy babies lose a little weight in the first days, start gaining again by about two weeks, and then grow fast. By four to six months, a baby’s weight is usually about double the birth weight. After that, growth slows down.

This guide explains how doctors judge growth, what milestones to expect between birth and one year, and which signs mean you should talk to a doctor.

Normal weight changes in the first year

MedlinePlus explains that babies normally lose about 10% to 12% of their birth weight soon after birth, then start gaining by about two weeks of age. By 4 to 6 months, weight should be double the birth weight. Growth in the second half of the year is slower than in the first months, and in the second year toddlers gain only about 5 pounds (around 2.2 kg).

Healthy children follow their own growth curve. Some babies are naturally small and some are bigger. What matters most is that your baby keeps following a steady curve over time rather than matching another baby’s weight.

• First 2 weeks: early weight loss, then weight starts to climb
• 2 weeks to 6 months: the fastest gain, with weight doubling by 4 to 6 months
• 6 to 12 months: slower, steady gain as your baby becomes more active
• After 12 months: growth slows further, and appetite may be smaller

What the WHO growth charts show

The World Health Organization (WHO) growth standards describe how children aged 0 to 5 years should grow when their needs are met. They were built from a study of 8,440 children from Brazil, Ghana, India, Norway, Oman and the United States whose mothers breastfed and did not smoke. This means the charts apply to children of any ethnicity, income or feeding method, and the breastfed baby is the benchmark.

Each child should have an individual growth chart, checked over time. A single weight is less useful than the pattern across several visits. WHO also notes that the standards allow growth speed to be tracked, so a problem can be spotted before a child falls below a cut-off. In India, ask your doctor or health worker to plot your baby’s measurements on the chart in the child health card.

Tip: weigh your baby at clinic visits, not daily at home. Day-to-day changes in weight are normal and can cause needless worry.

Feeding and growth

WHO advises exclusive breastfeeding for the first six months, then safe and nutritious local foods alongside continued breastfeeding up to two years or beyond. Our guide on starting solid foods explains how to begin. Signs of good feeding include steady weight gain, regular wet nappies and a baby who seems satisfied after feeds. For newborn feeding patterns, see newborn feeding schedule and hunger cues.

Milestones month by month

The US Centers for Disease Control and Prevention (CDC) lists milestones that most babies reach by certain ages. Treat them as guides, not strict deadlines. Every child develops at their own pace.

By 2 months

• Calms when spoken to or picked up
• Looks at your face and smiles when you smile or talk
• Makes sounds other than crying and reacts to loud sounds
• Holds the head up on the tummy and moves both arms and legs

By 6 months

• Knows familiar people and laughs
• Takes turns making sounds with you
• Reaches for a toy and puts things in the mouth
• Rolls from tummy to back and leans on hands when sitting

By 9 months

• Shy or clingy around strangers
• Makes many sounds such as “mamama” and “bababa”
• Looks for objects that are dropped out of sight
• Sits without support and gets into a sitting position alone

By 12 months

• Waves “bye-bye” and plays games such as pat-a-cake
• Calls a parent “mama” or “dada” and understands “no”
• Pulls up to stand and walks holding on to furniture
• Picks up small bits of food between thumb and finger

Babies born early often reach milestones later. Doctors usually judge them by corrected age; see our guide to premature baby care and development.

Supporting your baby’s development

• Talk, sing and read to your baby every day
• Give supervised tummy time while awake
• Offer safe toys to reach for, shake and hold
• Respond to your baby’s sounds and cries with warmth
• Keep vaccinations and checkups on time; see the baby vaccination chart

When to be cautious: do not compare your baby with a neighbour’s child or with a social media chart. Use your child’s own growth card and your doctor’s advice to judge progress.

Common myths about baby growth

Myth: a bigger baby is always a healthier baby

Fact: healthy babies come in many sizes. WHO standards also flag excess weight, so a steady curve is the goal, not the highest weight.

Myth: a baby who is smaller than others is not eating enough

Fact: many small babies grow normally along a lower curve. A doctor looks at the whole pattern before deciding if there is a problem.

When to see a doctor

The CDC advises talking with your child’s doctor if your baby is not meeting one or more milestones, has lost skills they once had, or if you have any concern about their development. Ask about developmental screening. Also ask for a check if:

• Weight gain stops, or your baby’s weight drops across the growth chart
• Your baby is not feeding well or seems unusually sleepy
• Your baby does not respond to sounds, or does not look at faces
• Your baby was born early or has a health condition and you are unsure what to expect
• You are worried for any reason

A baby who has trouble breathing, a seizure, or is very hard to wake needs urgent care. See our emergency page for 24/7 emergency care, and our postnatal and newborn care speciality for routine support.

Talk to a doctor

If you have any worry about your baby’s weight, feeding or milestones, early advice can put your mind at ease. You can book an appointment or call +91 944 103 0587. This article is for general awareness and is not a substitute for a doctor's advice.