by Doctor Mummy | 11:11

I recently found my diary from when my eldest, L, was a baby. I don’t remember her having a 4 month sleep regression (she wasn’t a great sleeper anyway) but when I read back, it was about the 4 month mark that I started panic-buying baby sleep books so there must have been some change.


My youngest, J, is a different matter. J slept through with just a single night feed from when he was about two and half months old. It was bliss. Then he hit four months and started to wake more. Unfortunately, J turning 4 months old coincided with a heatwave, which didn’t help much. J’s 4 month old sleep regression was very obvious!


He’s now five months and we are coming out the other side. He isn’t quite back to normal yet, but he’s sleeping 6pm-7am with just two feeds, which I’m happy with.


Having made it out the other side, I thought it would be helpful to have a look at the 4 month old sleep regression and what you can do about it.


Why does it happen?

Babies’ sleep patterns mature at 4 months old and they start to have proper sleep cycles. Sleep cycles last between 60-120 minutes and at the end of each cycle they wake briefly (adults do this too). It’s thought to be a protective measure – we briefly wake to ensure that we are safe and all is well, then fall back asleep. Most of us have no memory of even waking.


The problem is that if baby wakes and all isn’t well (from their perspective) then they do what any sensible baby would do – they call for their parents. Young babies really only wake naturally if they have a need – they’re hungry, wet, cold, hot or have had enough sleep. Older babies wake because they’re designed to do so.


When your baby wakes up they might think something’s wrong if, for example, they fell asleep in bed next to you and are now in their cot. They may think something is wrong if they are still tired but don’t know how to get back to sleep. They may think something is wrong if the room was light and now it’s pitch black. Basically any change can trigger it.


If this happens then instead of a brief waking that neither you nor they are really aware of, they wake fully and call for you. If this is happening every 60-120 minutes then the two of you are in for a very disrupted night.


Where I went wrong

Hindsight is a marvellous thing and reading my old diary I’m frustrated because it seems so clear to me what I did that exacerbated L’s poor sleep, but at the time I couldn’t see it at all.


L usually went to sleep either feeding or being rocked. When she started waking up more at 4 months old, I just put her back to sleep the same way. Breast milk was like a wonder drug, a quick feed and she was out like a light. On the rare occasion that failed, a few minutes rocking her and she was down.


This was very well-intentioned but two things happened – these became L’s firmly entrenched sleep associations, and she started feeding more at night and less during the day. This meant that she didn’t know how to fall asleep without being fed or rocked and she was taking in fewer calories in the day so waking genuinely hungry at night.


I’ve previously written about how we overcame L’s dependence on being fed and rocked to sleep and encouraged other sleep associations, but it was a slow process. If you’re reading this and your baby is younger than 4 months old then the best thing is to try to give them a range of sleep associations that you’re happy with and head off trouble early on!

If you’re already in the 4 month old sleep regression

I learned from my experience with L, so I’ve worked hard to encourage J to be a good sleeper from the start. He is perfectly happy to be put down awake in his cot and go to sleep with me just sitting beside him. He doesn’t rely on any one method for falling asleep and I got him used to sleeping in his cot instead of the sleepyhead pod just before 4 months.


That didn’t stop him from hitting the 4 month sleep regression, but it did make it easier to deal with. If your baby is already reliant on certain ways of falling asleep, you can read my earlier article on how to break sleep associations that don’t work for you and encourage a range of new ones.


Assuming that you’ve done this and your baby is able to fall asleep by himself so isn’t simply crying because he needs your help to fall back asleep, think about what else could be causing him to think ‘something’s wrong’ during his brief waking at the end of a sleep cycle.


Change in environment

One of the easiest ways to avoid the ‘something’s wrong’ response is to make sure that baby is falling asleep in the same environment he wakes up in. You can use gro-blinds to ensure it’s consistently dark, sleep aids for comfort and a consistent routine so baby knows you are leading up to the ‘big sleep’ and not a nap.


This is also a good time to consider stopping moving baby when he is asleep. I know it’s tempting to let them fall asleep next to you and then transfer them to their cot (I often did this with L), but they’re now old enough to notice and object to this! Think of how disorientating you would find it if you fell asleep in bed and woke up on a mattress in your kitchen – it’s the same for your baby.


Current advice is to always be in the same room as baby until he is at least 6 months old.  This is to reduce risk of SIDS.  This makes it difficult to achieve a consistent environment, unless you are willing to sit in your room with baby all evening!


If your baby still tolerates falling asleep in the living room with you and then being moved to your bedroom, fantastic.  If not and he is waking or you can’t get him to fall back asleep easily after the move, then you need to judge the risk and decide what you’re comfortable with.  Personally, I started putting both of mine down for the night in their cot in our room, as they didn’t settle well after being moved.


You can read more about safe sleeping guidance here.



Baby may become more aware of the world and so easily distracted during the day, but it’s important he is feeding well in the daytime and not relying on night feeds to get his calories. I went through a phase of having to feed both of mine in a quiet room alone, as otherwise they weren’t feeding properly!


Even if your baby is feeding well during the day, she might still wake up genuinely hungry and it can be hard to tell the difference between true hunger and comfort feeding. J has been waking more during the heatwave and wanting fed, but this makes sense – I’m thirsty at night too as it’s so hot, so why wouldn’t my baby be?


Your baby’s usual feeding pattern should give you an indicator of whether she might be truly hungry. J feeds three hourly during the day, so if it’s been over three hours since his last feed and he wakes overnight then I suspect he may be hungry. I’ll try to settle him first, but if he’s not settling quickly (unusual for him) then I’ll pick him up and feed him.


Older babies, bigger babies and babies in hot weather may start to need fed more often. J is over 95th centile for length, five months old and exclusively breast-fed so I’ve accepted that he may now need two feeds overnight until he starts on solids – no point in trying to force him back to one feed a night if he’s truly hungry!


It will pass

If you’ve made sure that your baby’s environment is consistent, she knows how to get herself back to sleep when she wakes and she’s feeding often enough, then if she’s still waking more than before it may just be a case of giving it time (sorry).


It’s taken J about a month to get back to a sleep pattern that I’m happy with. Part of it is that he’s made some pretty big leaps developmentally – he’s learned to roll over and has even managed to do a (very slow) commando shuffle forwards on his tummy to get what he wants. He’s working hard on sitting up. His favourite time to practice all these skills? Night time.


If your baby is busy working out how to do something – whether it’s babbling more or getting mobile, his sleep may be disrupted as he works on this new skill.


It’s frustrating – I was really proud when he started rolling over on to his tummy but after a few nights did descend to shouting ‘for goodness sake, if you don’t like being on your tummy then don’t roll’ when he woke me up for the fifth time showing off his newfound talent!


If there is something obvious irritating him – J kept getting his legs stuck out of the cot when he rolled about – you can try to solve it. I started putting J to bed in just his nappy and a 1-tog sleeping bag, instead of a nappy and sleep-suit. This stopped him getting his legs out of the cot, but didn’t stop the constant rolling about and attempting to crawl!


Unfortunately though, you can be doing all the right things and your baby might still wake up – in that case, you’ve just got to wait it out. I promise it will pass eventually.


I hope you’ve found this discussion of the 4 month old sleep regression helpful. Please comment below if you have any further questions, tips or suggestions!





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Corey Watson

I had similar issues with my oldest. He was a major crier and not a sleeper at all. still isn’t and he is 10. He fully relied on me nursing him to sleep – I was glad to do so with him because he screamed for the first 4 months of his life and him sleeping gave me a break that was much needed. My second child nursed in a similar way but that was totally my own fault. I never realized there was a change at 4 months old and had I read this article when they were little I would likely have done things differently. Great article and good advice for new moms!

Jul 27.2018 | 11:09 pm

    Doctor Mummy

    Hi Corey, thanks for commenting. Sorry to hear you found sleep so hard when your two were little. I too got in to the habit of feeding my eldest to sleep and it became a very hard habit to break! Please feel free to pass the article on to any mums who you think might be interested!

    Jul 29.2018 | 06:03 pm

Brandi Gray

This is such a great article, very informative. I do not have any children, yet, but reading this article surely has helped me gain knowledge of what to expect and how to readjust some things whenever I have children.
I do have a Goddaughter and my husband and I used to keep her overnight and she would always wake up in the middle of the night. She is now 1 years old and sleep through the night. Thank God!
Thanks so much for this post, very helpful!

Jul 27.2018 | 11:15 pm

    Doctor Mummy

    Hi Brandi, thanks for commenting. Glad that you found the article informative, hopefully some of the tips for older children will also be helpful for your godchild!

    Jul 29.2018 | 06:01 pm

shalisha alston

This is good to know! I don’t have kids, but it’s still good to know. It makes sense that a baby would think something is wrong if he wakes up in a different environment other than what he went to sleep in. Also, I didn’t know that learning new skills would be the stimulus for the baby waking up at night. Rolling over on the tummy. That makes sense too. All this talk about babies makes me wish I had one – kind of.

Jul 27.2018 | 11:28 pm

    Doctor Mummy

    Hi Shalisha, thanks for commenting. Glad that you found the article informative!

    Jul 29.2018 | 06:00 pm


Thank you for sharing your experience with sleep regression. My baby sleeps pretty well right now, but she is only 3 months old. I’m hoping she continues to sleep well, but I’m sure there will be some disturbances when she starts hitting more milestones. I will keep the tips you shared in mind moving forward!

Jul 27.2018 | 11:45 pm

    Doctor Mummy

    Hi Kait, thanks for commenting. I sincerely hope that your baby avoids the 4 month old sleep regression, but if not then hopefully you will find some of these pointers helpful!

    Jul 29.2018 | 05:59 pm


Amy, you have walked me down memory lane with your article. My son is now 18, but I remember soooo fondly when he was 4 months old. It happen to coincide with the summer months, and we were just back from our month-long stay in Italy to visit my family for my son’s first time. It was absolutely beautiful finally to be the two of us, and of course he was so much more alert and playful and laughing – 4 months is when the start giggling, is it right? and that giggle and that laugh was the most infectious laughter I have ever come across. But I wish your website had existed 18 years ago, as with the newly found energy my son did find also ways to stay awake at night. Not that it helped get rid of the problem, as the problem went by itself – as you say, they do grow out of it. But one advice my midwife gave me at the time was to sleep when baby slept. Easier said than done though, especially if this is not your first child. I am sure your suggestions in this time and age are far more helpful 🙂

Jul 29.2018 | 01:00 pm

    Doctor Mummy

    Hi Giulia, thanks for commenting. You’re right, 4 months is a lovely age (sleep regression aside!) and yes, that is when most babies start giggling! Most of my day is spent trying to get L and J to laugh just now. I also remember being told to sleep when the baby sleeps, but rarely managed this with my first and not at all with my second as the toddler isn’t allowed to sleep in the day!

    Jul 29.2018 | 05:58 pm

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