The dreaded 4 month regression is a subject I see questions about the most. I know from personal experiences with my own children how difficult this regression can be, on everyone involved. The 4 month regression is what led me to sleep training, when my first son went through it! It is truly one of the most dreaded regressions in the world of sleep.
Why does this regression occur?
At the age of 4 months your once "sleepy" newborn is not only becoming more aware of the world, but developing more adult like sleep patterns. This means, your little one now has 5 sleep cycles, resulting in transitioning through, and remaining in, lighter sleep cycles more often than ever. Of course, because of these lighter sleep cycles, you will find your little one waking frequently at night, having short naps, and sometimes no longer accepting help with their sleep (swings, bright spaces, car rides, etc) Every time your baby transitions out of a deep sleep cycle, and into a lighter one, there is a good chance they will wake up, and require assistance to fall back into the next sleep cycle.
When does this regression start?
This regression can start as early as 3 months, and as late as 5 months. The most common age is 3.5-4 months of course.
When does this regression end?
The easiest way to put this - it doesn't. This regression is a permanent change to your baby's sleep patterns. Some babies may come out of it on their own, but the majority of babies will need to change their sleep habits in order to sleep well again.
How does the regression present itself?
Naps: Naps are quickly becoming a nightmare. What once worked before, is not longer working. Baby-wearing, swing/car naps, nap holding, etc, are now much less effective, and a whole lot of work for everyone.
Reverse Cycling: This simply means your baby is eating more overnight than during the day. This happens when baby is waking frequently, parents cannot get baby back down, so a feed is offered. This is repeated multiple times a night until finally, its morning. This is a vicious cycle of baby getting most of the needed calories during the night, and not enough in the day. This is often how a feeding association is created, which is hard, but do-able habit to break.
Frequent Night Wakings: Maybe your baby was once a great sleeper, maybe they weren't. Either way, when you are in the regression, you will know it. Baby will try likely be waking every 45 minutes - 2 hours during the night.
Other things to note:
This is often around the same time that the rolling milestone comes into play for most babies. I often hear "can my baby sleep like this she got there by herself!" The answer is yes. Once your baby can roll onto his/her belly unassisted, they are fine to stay that way. This is often difficult for parents to accept. We are programmed by society to believe that any form of belly sleeping is dangerous, but the AAP suggests if baby has gotten into that position, and is in a safe sleeping environment, you are good to go! Now some babies will roll onto their bellies, and never leave them (mine included). However, some babies are not fans of belly sleeping, and will likely cry out for help if they cannot flip over independently. The best way to handle this is to practice, practice, practice during awake periods. Next, give your little one space when they do flip. Just like your little one needed time/space to learn the belly roll, he/she needs space to master the back roll as well!
How do you survive this dreaded regression?
Change the way you respond in the night: If baby is waking frequently overnight and your first thought is to feed, take a deep breath and give them a few minutes. It is important to not over compensate with feeds during the night, which results in the reserve cycling mentioned above. It is important to allow your baby 10-15 minutes of independent time, to see if they can transition into the next sleep cycle on their own. I recommend only 1-2 feeds at this age (always get the go ahead from your doctor first)
Introduce independent sleeping skills: This is a big one for babies who are reliant on help for all sleep. If independent sleeping skills were not introduced prior to the regression, now is the time. You will not see your child's sleep improve much, if at all, without removing those dependencies surrounding their sleep.
Nap, nap, nap: Naps are a HUGE part of making night sleep a success. If your child is getting too much, or too little day time sleep, it can negatively impact their night sleep. Naps need to be a priority at this point, and its very important to follow an age appropriate schedule. Some 4 month olds are able to extend naps earlier than others, which means they can do 3 naps a day. However - it is normal for most 4 month olds to still need 4 naps a day. At 4 months of age, your little one's awake time should be approximately 2 hours, with 4 hours of day time sleep.
Check environment: Double check your little one's sleep environment to ensure it is encouraging to sleep. The room should be pitch black, correct temperature and using white noise.
As a mother, and a Certified Sleep Consultant, I understand the desperation that comes from the 4 month regression. If you and your family are currently struggling, do not hesitate to reach out for help!