Baby development: how it happens

Baby development in the first 12 months is amazing because so much happens. Most healthy babies develop new skills in a completely natural and continually surprising way.

Babies all grow and develop at very different rates – and they don’t always do what the parenting textbooks say they’ll be doing!

If your baby is eating and sleeping well and seems mostly happy when she’s awake, she’s likely to be developing well. You know your baby best – if you think she’s OK, she probably is. But if you’re worried about her development, trust your instincts and talk to your GP, child and family health nurse or paediatrician.

Baby developmental milestones

Developmental achievements are called ‘milestones’. Growth and development milestones are a useful guide for tracking your baby’s development.

Developmental milestones are grouped under headings according to the parts of the body they refer to:

  • Large body movements (gross motor skills) involve the coordination and control of large muscles, and skills like walking, sitting and running.
  • Small body movements (fine motor skills) involve the coordination and control of small muscles, and skills like holding a rattle and picking up crumbs.
  • Vision is the ability to see near and far, and to understand what you see.
  • Hearing is the ability to hear, listen to and interpret sounds.
  • Speech and language is the ability to produce and understand sounds that form words.
  • Social behaviour and understanding is the ability to learn and interact with others. It includes skills for play and connecting and communicating.

Developmental delay

Some babies have delays in their development, but it’s hard to predict whether these delays are short term or permanent. Permanent delays don’t happen often.

Premature birth or other illness and injury that affect brain development are some of the things that might cause developmental delays.

Babies’ development can also suffer because of their environment. For example, baby development can be affected if babies don’t have warm, responsive and reliable relationships with those around them, if they don’t have predictable routines that help them feel safe, or if their parents abuse alcohol and other drugs or are involved in family violence.

Things to watch out for in baby development

Every baby develops differently, and there’s a big range of ‘normal’.

Try not to compare your baby with others, because this can lead you to worry when you don’t need to. Comparing your baby to others can even have a negative impact on your relationship with your child.

But as a general guide, if you’re seeing delays in a few different areas over several months, it’s a good idea to seek advice from a health professional. Here are some signs to look out for.

Physical signs
Your baby:

  • doesn’t seem to see things or hear properly
  • doesn’t move or use both arms and/or legs
  • can’t hold his head up by the time he’s reached 3-4 months
  • isn’t sitting well by 10 months
  • doesn’t want to stand up, even if you support him, by 12 months.

Behaviour signs
Your baby:

  • is persistently crying for more than three hours a day, especially after 3-4 months (it’s normal for babies to cry for about two hours a day, with crying peaking at 6-8 weeks)
  • has an unusual cry – for example, a high-pitched squeal.

Social, emotional and communication signs
Your baby:

  • doesn’t look at you
  • isn’t interested in what’s going on around her
  • doesn’t consistently respond to sounds
  • isn’t babbling by 9 months or is using fewer than five words at 18 months.
It’s normal for babies to do actions like waving, clapping or making a particular sound, then suddenly stop. These actions usually reappear. It might be that your baby is fascinated by learning a new task. But if your baby shows signs of forgetting skills over several months or if you’re concerned, you should talk to your GP, child and family health nurse or paediatrician.