3 Month Milestones: What Most Babies Do at 12 Weeks (Australia)

The 3 month milestones most babies show around 12 weeks are steadier head control, a lifted head and chest in tummy time, hands brought together in the middle, real smiles and eye contact, cooing back at you, and, for many, a longer first stretch of night sleep. Every one of these has a wide normal range.

This page zooms in on one age. The wider picture, birth to 24 months, lives in our guide to baby milestones by age. The month before is covered in 2 month milestones and the month after in 4 month milestones.

What do most babies do at 12 weeks, by area?

The list below is drawn from the birth to 4 months band of the ACECQA developmental milestones(opens in a new window), the national reference used by early childhood educators in Australia. It is the same checklist the BabyLog milestone tracker records, so what you tick here is what the app tracks. The rows lean towards the skills that arrive in the third month rather than the newborn reflexes.

• Physical: Lifts head and chest when lying on their tummy; begins to roll from side to side; reaches to swipe at dangling objects; grasps an object put into their hands.
• Social and emotional: Smiles and laughs; makes eye contact when held about 20 cm from your face; is alert and preoccupied with faces; turns their head to voices; shows excitement as you get a feed ready; crying peaks at six to eight weeks and levels off at about 12 to 14 weeks.
• Communication: Coos and gurgles; makes small throaty noises when content; may start to copy sounds; is soothed by your voice or low rhythmic sounds.
• Cognitive: Eyes track a slow-moving object for a short time; looks at edges, high-contrast patterns and faces; looks towards a sound; copies your tongue movements when held close and talked to.

Read the whole list, not one line. A baby pouring effort into tummy time can look quieter on cooing for a fortnight.

Is 12 weeks the same as 3 months?

12 weeks is about 2 and three-quarter months. Your baby turns 3 months on the same date three months after birth, about 13 weeks. Milestone guides use 3 months for roughly 12 to 14 weeks, so the 12-week and 3-month lists are the same.

The gap comes from the calendar. A month is not four weeks: most months have 30 or 31 days, so a month averages a little over 4.3 weeks. Three calendar months from birth is 89 to 92 days, depending on the months involved. 12 weeks is 84 days, so a 12 week old turns 3 months about a week later.

Milestone guides do not split that week. The Raising Children Network's development tracker runs a 2 to 3 months(opens in a new window) stage straight into a 3 to 4 months(opens in a new window) stage, so a 12 week old sits at the join. The ACECQA developmental milestones(opens in a new window) go further and treat birth to 4 months as one band.

For a baby born early, count corrected age as well. The Sydney Children's Hospitals Network(opens in a new window) defines corrected age as the time since birth minus the weeks your baby arrived early. A 12 week old born 4 weeks early has a corrected age of 8 weeks, so the 2 month milestones are the closer guide for now.

What is typical at 3 months?

Head control and mini push-ups

Most 12 week olds hold their head steadier when you hold them upright or help them sit, and many lift their head and chest off the mat in tummy time. The Raising Children Network(opens in a new window) describes babies at 2 to 3 months resting on their forearms when on their tummy, with head control still emerging, and by 3 to 4 months pushing up on forearms or hands(opens in a new window) with the head held high.

That push-up is built on the floor. Pregnancy, Birth and Baby(opens in a new window) suggests short goes of tummy time that add up to at least 30 minutes across the day, always with you watching, and back to sleep every time.

Hands find each other

Around 12 weeks the fists open. The Raising Children Network(opens in a new window) notes that at 2 to 3 months a baby's hands are open most of the time, and many babies enjoy opening and closing them and bringing them together. Pregnancy, Birth and Baby lists hands together near the middle of the body among the physical changes at 3 months, alongside reaching for objects and putting things in the mouth.

Cooing and turn-taking

Crying is still the main language at 12 weeks, and it usually has company now. Pregnancy, Birth and Baby describes more cooing and gurgling sounds when a 3 month old is calm and content. The Raising Children Network adds that by 3 months a baby might coo and even echo you, and by 3 to 4 months makes sounds like 'ah-goo', listens when you talk and tries to reply.

Those replies are the first conversation. Pause after you speak and let bub fill the gap.

Raising Children Network · Baby development at 3-4 months

When you talk, your baby listens and tries to reply.

Longer night stretches

Many families notice the first longer sleep around now. Pregnancy, Birth and Baby(opens in a new window) says that by 3 months many babies settle into longer wake times in the day and longer sleeps overnight, often a continuous 4 to 5 hour stretch. Plenty of healthy 12 week olds still wake for one to three feeds. What the change looks like month by month is in our guide to night feeds by age.

Why is my 3 month old still crying, and when does it ease?

Crying usually peaks before this age and eases through it. The ACECQA milestones describe crying peaking at about six to eight weeks and levelling off at about 12 to 14 weeks, and the Raising Children Network(opens in a new window) gives 12 to 16 weeks for any extra crying and fussing to settle. If your 12 week old cries a lot and is hard to soothe and that worries you, that is on the nurse's list, not a sign you are doing something wrong.

Two things can make a settled baby fussier for a few days at this age. Pregnancy, Birth and Baby(opens in a new window) notes that babies may have a growth spurt at about 3 months and want to feed more than usual. Straining or crying before a poo is also common at 3 months as babies learn to use their muscles.

One safety point sits with the new wriggling. A 12 week old may not roll yet, but they kick and squirm hard, so Pregnancy, Birth and Baby's advice is to never leave a baby alone on a change table or any raised surface.

Crying peaks around six to eight weeks and eases around 12 to 14. If you are reading this at 12 weeks, the worst of it is usually behind you.

Which child health check falls around 3 months?

Usually none exactly at 12 weeks. Pregnancy, Birth and Baby(opens in a new window) lists routine baby checks at birth, 1 to 4 weeks, 6 to 8 weeks, 4 months, 6 months and 12 months, so a 3 month old sits between the 6 to 8 week check and the 4 month check. Victoria's 4 month maternal and child health visit(opens in a new window) reviews growth, health and development, works through the parent development questions in the green book, and covers safe sleeping, immunisations and first foods. Each state runs its own schedule and record book, and our guide to baby health checks in Australia sets those out.

Weeks 10, 11 and 12 at a glance

Early clinic visits and the rotavirus cut-offs count in weeks, while milestone guides and most vaccine visits count in months. The same baby can be 11 weeks at the clinic and 2 months in a guide. This list lines up the weeks this page covers with the months, the guides and the Australian check and vaccine points.

• 10 weeks (70 days): About 2 months and 1 week. Guides put it in Raising Children's 2 to 3 months stage. Checks and vaccines: 2 month vaccines overdue if not yet given; book a catch-up.
• 11 weeks (77 days): About 2 and a half months. Guides put it in Raising Children's 2 to 3 months stage. Checks and vaccines: Victoria's next maternal and child health visit is at 4 months.
• 12 weeks (84 days): About 2 and three-quarter months. Guides put it at the end of the 2 to 3 months stage and on Pregnancy, Birth and Baby's 3 month page. Checks and vaccines: if 2 month vaccines were missed, first rotavirus dose by 14 weeks.
• 13 weeks (91 days): About 3 months. Guides put it at the start of Raising Children's 3 to 4 months stage. Checks and vaccines: 4 month vaccines about a month away; 4 month check in Vic, WA and ACT.

If the 2 month vaccines have not happened yet, book them now rather than waiting for the 4 month appointment. The National Immunisation Program schedule(opens in a new window) says the first rotavirus dose must be given by 14 weeks of age and the second by 24 weeks. Ask your GP or immunisation provider about a catch-up.

What about 10 and 11 week milestones? They come from the same ACECQA birth to 4 months list as 12 week milestones, often at an earlier stage. A 10 week old is often smiling back, watching faces and making the first coos, while steadier head control and forearm push-ups are still coming. The 2 month milestones page covers where these skills start.

When to talk to your child health nurse

The Raising Children Network(opens in a new window) and Pregnancy, Birth and Baby(opens in a new window) both suggest a chat with your child health nurse or GP if a 3 month old:

• is crying a lot and is difficult to soothe, and this is worrying you
• is not looking you in the eyes, even briefly, or does not pay attention to faces
• is not smiling when you talk to or smile at them
• is not making sounds when you speak to them
• does not react to loud noises, or is not distracted by a rattle
• is not feeding well at the breast or bottle, or seems very tired
• keeps their hands in a fist most of the time
• is very floppy or very stiff, or is not moving their arms or legs

At any age, a skill that was there and has gone is worth a visit on its own. healthdirect(opens in a new window) puts it simply: most children learn these skills in the same order, but not always at the same time.

Keeping track at 12 weeks

The 4 month check asks what you have noticed, and three weeks is long enough to forget whether the first laugh came before the first roll to the side.

BabyLog's milestone tracking, part of Pro, uses the same ACECQA checklist as the list above. Mark a milestone as one to watch, then tap it when it happens. The moment is stamped with the date and your baby's exact age, and every caregiver sees the same list. For the check itself, a checkup report on Pro pulls feeding, sleep, growth and the milestone checklist for the stage you pick into one summary you can share as a private link or PDF.

Common questions