Your baby’s growth spurts

Your baby’s growth does not happen in a linear and continuous way. In fact, growth typically happens in bursts – a child can rapidly gain height or weight in a matter of days or weeks. In fact, according to childhood development expert Dr Michelle Lampl, a child can grow as much as 9mm in 24 hours. (1) A baby is likely to have doubled their birth weight by the time they are five months old and tripled in weight by the time they reach one year of age.

It should not be surprising then that when a baby is experiencing a growth spurt they can become irritable, insatiably hungry and have difficulty sleeping. In the article below, we take a look at baby growth spurts so that you can understand and support your child through periods of fast growth periods.

What is a growth spurt?

A growth spurt is any period in which your baby gains weight or height during a short amount of time. There is no accepted technical definition of what constitutes a “spurt”, although most experts seem to agree that they last between two and seven days.

When do growth spurts happen?

Once breastfeeding has established and newborns have regained their birth weight, the first growth spurt will usually happen at around seven to ten days old; the second at around three to six weeks, with four or five growth spurts happening over the next 11 to 12 months, typically at three, six and nine months.

Growth spurts – what to look out for

Often your child may have a growth spurt without you even realising it, that is until one day you notice they no longer fit into their sleepsuit. However, there are some growth spurt signs to look out for. These might include:

  • Irritability: if your baby seems a little grumpy and tired, it could be because she’s using all her energy to grow.
  • Increase in appetite: if your child suddenly wants to breastfeed, bottle-feed or, once weaned, eat all the time, it could be a sign that they need extra energy for growth.
  • Difficult nights: if your baby seems restless and is waking during the night, it could be a sign that a growth spurt is causing some discomfort and internal upheaval.

Growth spurt or something else?

Although growth spurts can make your baby hungry, irritable and generally below par, they do not cause fever, floppiness or significant fatigue. If your baby is experiencing any of these symptoms, you should contact your GP.

Similarly contact your GP if you have any particular concerns about changes in your baby’s mood, alertness, sleeping habits or behaviour.

Lastly, growth spurts can be confused with and may sometimes occur simultaneously with teething, so if your child experiences symptoms of teething such as reddened cheeks, drooling or sore gums, it may be that your baby is cutting new teeth.

How to help your baby manage growth spurts

The most important thing is to keep calm and not worry too much. Growth spurts are entirely normal and natural, and your baby’s irritability will pass in just a few days. However, if there are other symptoms, such as a rash, high temperature or vomiting, then you should always get your baby checked out by your healthcare team.

The human growth hormone (HGH) is responsible for growth spurts and since this hormone is produced during sleep, you might want to allow your baby/child a few additional hours sleep if possible, even if this means an extra nap in the day.

Lastly, although your child may need additional food, guard against overfeeding as this may only serve to make your baby more irritable. Remember, if she turns her head away from the breast or bottle, she has had enough.


Baby growth spurts are a normal part of development. However, given that babies can grow very quickly over a period of just a few days it is understandable that growth spurts can leave them feeling a little irritable and off-colour.