What is 4-month sleep regression?
Is 4-month sleep regression a myth?
How long does 4-month sleep regression last?
Will I ever get a full night’s sleep again?

There you were giving yourself a high five and pat on the back because you were finally seeing improvements in your baby’s sleep.
They were sleeping for more extended periods; perhaps even through the night, their daytime naps were starting to have some predictability when
BAM!
Your baby is suddenly waking up multiple times in the night and seems to be resisting naps.
What happened?
Where did it all go wrong?
Do not despair
The Good News
This is entirely normal.
Not So Good News
It will last for about 2 – 6 weeks.
But Good News
It will not last forever.
In this post, I will attempt to answer your 4-month sleep regression questions without over complicating the issue.
What is 4-Month Sleep Regression?
4-month sleep regression is a perfectly normal developmental stage for your baby, although a very exhausting stage for you as the parent.
The way to look at this is not as regression but as progression. Your baby's sleep cycle is maturing. Your baby is now no longer a newborn (I hear a few melancholy sighs). On the one hand, it is sad to think that your little one is no longer a newborn, but on the other side, you are entering a new and exciting stage of your baby's development.
During this developmental stage, you may find your baby waking up more frequently at night. You may also find that their daytime naps are shorter and not as predictable.
What Causes 4-Month Sleep Regression?
4-month sleep regression is a result of the maturing of your baby’s sleep cycle. Unlike newborn sleep which only has 2 sleep stages, adult sleep has 4 stages.

Your 4-month-old is now going from 2 to 4 sleep cycles, which means they are experiencing more periods of lighter sleep, and this can take a bit of adjustment.
This adjustment can also be more challenging for babies who have a dependence on sleep props to fall asleep and stay asleep through the night.
4-month sleep regression also occurs at a time where your baby is becoming more active and learning new skills. You may find at this age your baby is starting to become more aware of their surroundings, recognising faces and learning to rollover (not my son, I always used to joke he was a ‘lump’ as he only started rolling over at around 5 ½ months old).
Signs of 4-Month Sleep Regression
So how do you know if your baby is going through sleep regression? Well if your baby is around 4-months old and their typical sleep pattern changes, then they are probably experiencing sleep regression.
By 4-months old, your baby will have developed a typical sleep pattern. There is some predictability around what time and how often they wake at night. If your baby is not ill and you see changes to this pattern, then ‘Yes' you are probably in the throes of 4-month sleep regression.
How Long Does 4-Month Sleep Regression Last?
If you have gotten this far in this post, then you have probably realised that your baby's sleep is permanently changing, so 4-month sleep regression does not ‘end' in the real sense. Your baby will, however, get used to these new sleep cycles and go back to sleeping well after about 2-6 weeks. Most babies would settle after a couple of weeks, especially if your baby was sleeping well before.
If your baby was not sleeping well before the 4-month sleep regression, then chances are they will not sleep well afterwards.
If you have not thought about sleep training your baby before, now might be a good time to consider this. Unfortunately, poor sleep habits can last for months or even years.
You can read my personal sleep story and review of Dana Obleman’s Sleep Sense Program here.
Can You Prevent 4-Month Sleep Regression?
The short answer is ‘No' you cannot prevent this as it is part of your baby's healthy development. If you are reading this before your baby goes through the 4-month sleep regression, then you can, however, do a few simple things that will help your baby to transition through this inevitable stage more quickly.
- Get Rid of Sleep Props/Aids – You need to reduce and ultimately eliminate your baby’s dependence on any form of sleep props. Babies need to learn how to fall asleep independently and then stay asleep through the night.
- Put Your Child to Sleep in the Same Place Every Night – Putting your child to sleep in the same place every night (and for naps where practical) helps them feel safe and understand that this is the place where you expect your child to sleep.

- Create a Bedtime Routine – Your child is never too young to start a bedtime routine. The routine should be simple and easy to maintain every night.
- Create an Ideal Sleeping Environment – Your child's room should help promote sleep. Try to keep their room dark (lights dimmed at the very least), quiet and cool.
What to do During 4-Month Sleep Regression
As I said, you cannot prevent 4-Month Sleep Regression, but there are some things you can do to help your baby through his developmental stage.

- Stick with Your Regular Bedtime Routine – Babies love routine, and by continuing your already established bedtime routine, you will be reinforcing the message that it is nighttime and therefore sleep is expected.
- Do Not Let Your Baby Get Overtired – This can be a little bit tricky during this period as your baby will probably be sleeping less during the night. 4 months old babies need around 14-16 hours of sleep. If your baby seems tired in the day, try and make up for the lost rest with more naptime during the day.
- Stick with Your Normal Nighttime Waking Routine – As I mentioned earlier in this post now is not the time for sleep training. Continue with what you would normally do when your baby wakes in the night. If you usually go in and shush them or pat them, then continue to do this.
- Do Not Give Your Baby Any Additional Feedings – If your baby has still been feeding once or twice at night, then stick to this. Do not provide additional feedings just because your baby is waking up more than they usually would. Supplemental feeding will lead to your baby expecting this and may cause her to start waking up more often during the night even when the 4-month regression stage is over.
- Take Care of Yourself – Ask for help, get family and friends to watch your baby for a while so that you can take a nap.
To Sum It All Up
4-month sleep regression is real, unavoidable and completely normal. Most importantly, it is only temporary.
Your baby's sleep cycle is maturing, and during this stage, they will wake more often during the night, and daytime naps may not be as predictable as they were before.
Continue to be consistent so as not to unwittingly create poor sleep habits that will be challenging to change later.
If you have not started sleep training your baby, this is not the time to start; however, this is something you should consider so as not to endure more months and even years of sleep deprivation.
Take care of yourself, ask for help and keep reminding yourself that this will only be for a short time.
People who say they sleep like a baby usually don’t have one.
– Leo J. Burk