There is no reference to “sleep regressions” in academic or clinical literature. Yet, ask any parent their experience of sleep and almost all will mention, with fear in their eyes, any number of "regressions", with the absolute certainty that they are most definitely a "thing".
Personally, I try to avoid the term “regression” as it makes it sound as if things are going backwards and actually the opposite is true – whilst sleep can periodically deteriorate, and often around predictable ages/stages, if this does happen (and it is an "if" rather than a "when"), it is because a little one is leaping forwards in their development, which is something to celebrate rather than fear. It is also very possible to help your little one steer past any sleep-strains as confidently and successfully as possible.
There typically is a broad commonality in terms of children reaching various developmental milestones. Significant advances in a child's motor and/or language skills, can put a temporary strain on sleep, and it is common to see sleep wobble in the most acute periods of change.
Here is a look at the periods we tend to hear the most about...
Of all the sleep “regressions”, this is the most poorly named! Firstly, it takes place anywhere in the first 6 months and whilst month 4 is a common time, it’s as likely to occur at 3 or 5 months. Secondly, of all the changes in a little one’s sleep that are termed as a regression, this one should in fact be called a “sleep progression”.
Newborn sleep is more simple in architecture to that of older babies, children and adults. In-utero, babies spend most of their time in REM sleep, with a typical newborn sleep pattern manifesting at around 38-weeks gestation. Even then, newborns spend much of their time in REM sleep, thought be crucial for brain development and have short sleep-cycles of just 30-40 minutes. As babies advance through their early weeks, they begin to spend some of their time in NREM sleep, but even then do not sleep in the same way as adults. They completely skip the lighter phases of NREM sleep, meaning that when they have shifted into a solid sleep, they are really quite deeply asleep. It may be that the absence of the lighter stages of NREM sleep, is one of the reasons babies under 6-months are more vulnerable to SIDS. It is almost certainly why babies of this age can be placed into their beds having fallen asleep in arms or on the breast/bottle, and not wake for several hours - in fact, it's not uncommon for little ones of 10-12 weeks to sleep for stretches of 8-hours or more!
In line with every other aspect of your baby's biology, however, sleep changes, and, usually around their forth month, they make a shift to sleeping in a more organised and complex way, cycling through lighter and deeper sleep on a predictable pattern. Each cycle typically lasts around one-hour. In the periods of lighter sleep, little ones check in with themselves and also perform a check of their sleep environment. This is actually great news, as this regular rousing and heightened awareness helps to keep babies safe as they sleep. Another aspect of this inevitable maturating of sleep architecture is that a child will begin to wake in the night periodically - perhaps more frequently than they did before, hence why it can feel like things have gone backwards. They haven't, it's just that a baby has started to sleep more like the rest of us.
In the midst of this fairly seismic sleep-shift, many babies will wake very regularly indeed - perhaps as frequently as every hour. After a bumpy period, lots will settle into a more consistent pattern with two-to-four wakings each night. Others will continue to wake after much shorter chunks of sleep. This gruelling pattern can be particularly prevalent in little ones who are uncomfortable, overtired or those transferred into a sleep-space already asleep. And this is where the age-old myth of feeding/rocking a baby to sleep being a "bad habit" comes from...
Whilst there are some babies who can fall asleep however/wherever, be placed down already out-for-the-count and slumber happily until the morning, there are lots of little ones who rouse at the end of almost every sleep-cycle if there has been a significant change in their sleep environment. There isn't a secret baby training school that makes sure it graduates are in the first category - it's a lot to do with the natural relationship a baby has with sleep. And luck-of-the-draw!
The change to sleep-architecture is permanent. It always pays to let the dust settle on the initial shift, as many little ones will settle into a more manageable pattern after a gruelling week or two.
Once the peak of the fussiness has passed, it's a good time to take stock of whether your sleep situation is working for you. If it is, there is no need to change anything. I can't say it loud enough but the question is always whether the habits your family has around sleep are working for you? If they are, and sleep is happening safely, then even if your sleep-situation wouldn't work for your mother-in-law, your Health Visitor or Karen at baby class, the habits you have aren't "bad". On the other hand, if your family isn't getting the rest it needs, then it is absolutely worth reviewing how some gentle modifications may help. At this age, habits are not particularly set - in fact, they are barely even formed, which can make it a great time to start to experiment with what may work for you moving forward.
After the challenge of a child’s sleep maturing, things usually have settled down a little and a family may well have enjoyed a few months of restful nights. But the second half of the first year can also be a tricky time for sleep.
There is a lot going on for a baby developmentally in this window and it’s not a surprise that sleep is often affected. Little ones are typically working through the journey from crawling to standing - all steps on the path to walking. They may also be rapidly developing their language and communication skills. With learning to walk and learning to talk being two of the most significant developmental milestones of our entire lives, it's no small wonder that sleep can be a little bumpy in this window!
With periods of rapid development tend to come more night-wakings. This is often exacerbated by a deterioration in daytime sleep causing a little one to be overtired. Add into the mix that the third naps usually drops around the eight-month mark, and the separation anxiety that tends to arrive with a vengeance and it's actually surprising that children sleep much at all around this age!
Parents often report a deterioration in sleep somewhere around their child’s first birthday. For many little ones, this tallies with mastering the skill of walking, which of all the physical milestones typically has the most noticeable effect on sleep. Extended night-wakings are common around this time as a little one may either lie awake trying to work out how to walk or actually having a practice, despite it being 3am and him being in a cot!
As a little one can become tricky around their naps during this period, parents may (entirely logically) take it as a sign of readiness to transition to one nap. However, the two-to-one switch can be challenging and is typically more easily mastered from the age of 15 months upward. If there is nap-refusal happening in the 11-13 month window, I would typically advise initially assuming it is a phase and continuing to offer two naps. Very often, after a tricky week or two, a little one settles back into the two-nap pattern and remain there for another few months before tackling dropping the morning nap.
Typically, children who are more likely to resettle themselves when they wake are less noticeably affected by periods of sleep-strain. They may be waking more frequently, and even staying awake for a little while, pondering their next move or practising their latest skill - but, once ready to settle back off to sleep, will do so. Parents may not even notice these little ones have woken at all. Although, I remember a few nights around this age where by son would have a little run through of all the sounds he could make in the small hours of the morning! For children who require parental help to resettle, knowing why this has increased in frequency can help parents to cope with the additional nighttime disturbance.
It is still possible to work on a child's sleep habits during a sleep-strain - in fact, it is often a family's motivation for taking action! However, I would only recommend doing so if using a strategy where you are in the room with your child. Sometimes, when a child’s sleep has been reasonable for a spell and then a real fussy stage hits, parents believe their little one is acting up or being difficult around their sleep. This can then be a motivation to “sleep-train” – often switching from rocking or feeding-to-sleep to leaving their little one alone to cry. The step between these two extremes is huge and will be particularly hard on a child who is in the middle of a development leap and/or experiencing separation anxiety.
Whilst there is a lot of anecdotal evidence of a regression at this age, in my experience, any challenges arising are more to do with a little one’s emerging independence and a testing of the boundaries than genuine sleep interference - although separation anxiety can be playing a part. I always advise parents to remember that bedtime and sleep not take place in a vacuum – hence daytime behaviour will impact what goes on at night. This applies to the parents and their child! A little one who is testing the daytime boundaries is likely to do so at night – by association, children typically expect consistency from their parents so if they see that in the daytime, a parental “no” actually means, “OK yes if you shout loudly enough”, they will pretty inevitably expect bedtime boundaries to be similarly flexible.
It’s not uncommon for separation anxiety to re-emerge around this age. Again, a parent is likely to see evidence of this during the day as well as at night. Usually, the smoothest way through challenges around this age is for a parent to provide extra comfort and reassurance if it is sought whilst maintaining the boundaries - for example, providing extra support and reassurance by going into their child's room, as opposed to bringing the little one out into the parent's bed, if the family does not wish to bed-share on the other side of the sleep-strain. Whilst this means more disturbance for parents in the short-term, it keeps things as consistent as possible for a little one, who has less capacity to understand why the goalposts keep shifting.
Anyone who has parented a two-year old will know they can be tricky – and not just around their sleep! Most two-year olds go through a phase (or phases!) of not wanting to nap. Yet, most little ones really do need some daytime sleep until at least their third birthday and those who drop the nap earlier often see their night-time sleep adversely affected. It is advisable therefore to treat nap-refusal as a temporarily glitch – to keep offering the nap and working on the basis that it is needed.
This is a time of genuinely huge transitions for a child – potty-training, the move from cot to bed and for many little ones, the arrival of a sibling, all of which can impact sleep. Wherever possible, I advise parents to keep their child in a cot until they are at least two and a half. It’s not until around this age that a child really grasps the concept of “staying put” and so a move into a bed that doesn’t have sides is likely to mean a lot of time spent returning a little one to their bed. Of course, safety takes priority and if a child has become skilled in scaling out of their cot then the move to a bed may be necessary but as a general rule, a cot-escapee will transition smoothly into a bed-absconder and so if there is a way of keeping a little one safely in their cot that is usually the best way forward.
Finally, boundaries really matter to a two-year old so the best approach is to not say anything you don’t mean or won’t follow through – no matter how frustrated you are! You will find things settle more quickly if boundaries are age-appropriate, empathetic and and consistently applied.