Name two words parents dread more than sleep regression… we’ll wait.

We often hear about them in Whatsapp groups (why is my baby suddenly not sleeping?! Send coffee!), or in books about child development, with most agreeing the first sleep regression happens around the age of four months. Then eight months. Then 18 months and finally, two years.

But for lots of parents, it can feel like every week you’re starting a new sleep regression with a baby. And even when they’re toddlers, you’ll get the odd night where they sleep through in their cot (and you’ll pop some Prosecco in the morning to celebrate), but you’ll also get lots of occasions where they’ll wake up, end up in your bed, pull your hair, grab your lips and shout “DADDY!” approximately 59 times at 3.30am.

So what are sleep regressions – and why oh why does it feel like you’re constantly in one?

It turns out most sleep specialists don’t really consider sleep regression a thing, per se – the concept is not really used in scientific or medical contexts when discussing child sleep. That said, sleep specialists do recognise that lots of parents are aware of them.

“The only ‘regression’ with any science behind it, that I recognise, is the one that happens around four months old when babies’ sleep cycles actually change and become more like adult sleep,” says Emily Houltram, founder of The Sleep Chief. “But even that one divides professionals!”

Explaining what a sleep regression is, Lauren Peacock, a sleep consultant at Little Sleep Stars, says that “it generally refers to a sudden perceived deterioration in a child’s sleep pattern, typically characterised by difficulty settling at sleep onset and/or night-waking that is happening more frequently and possibly for an increased duration”.

Sleep isn’t linear, she explains, and like all other aspects of development, it matures over time with a noticeable change occurring in the first six months. “Once this change occurs, periodic night-waking becomes a normal part of the sleep pattern,” she says.

Then, whenever children hit a significant stage of their development – so that could be crawling, walking, talking, starting childcare, becoming a sibling, getting sick or teething (the list goes on), there is potential for their sleep to be impacted. Again, and again, and again.

Peacock suggests the term ‘regression’ is actually very misleading because none of these events occur as a result of a child going backwards – “they are only ever moving forwards,” she adds.

But for parents who aren’t sleeping that well, it can definitely seem like a step backwards compared to those halcyon days of newborn sleep when you could ease them gently back into slumber with a mere cuddle and a bit of milk.

Most babies will be impacted by a disruption to sleep at some point in their first few years, but some will be less impacted than others.

“All babies experience changes to their sleep pattern and many will go through phases where sleep feels more challenging,” says Peacock. “Some little ones do have a trickier relationship with sleep than others and so whilst some children will experience more frequent and persistent sleep disruption, others will navigate through these inevitable ups and downs much more smoothly.”

If you’re very much in the camp of surviving the day on four hours’ sleep and feeling like you might never get a good night’s kip ever again, we have some good news – and some bad news.

The good news is that this won’t last forever. When they’re teenagers they’ll be sleeping for lengthy stretches to the point where you’ll probably worry they’re sleeping too much.

The bad news is that even as your baby becomes a toddler, and then a young child, there’ll probably be a few bumps in the road as far as their sleep is concerned. (Like we said: basically one big sleep regression.)

:: Becoming more difficult to settle at bed or nap time

:: Waking more frequently than was previously typical

:: Waking in the night and then staying awake for a long period – something sleep experts refer to as a “split-night”

:: Waking up a lot earlier.

There is a popular narrative around sleep regressions occurring at specific ages: so typically we hear four months, eight months, 18 months and two years as inevitable points that sleep will deteriorate, says Peacock.

“However, some families will feel that their child never experiences a ‘regression’, whereas others will feel that they are hit hard by every single one – with some extra ones thrown in for good measure,” she says.

“There are ages that it is more common to see sleep challenges crop up, and they do tend to coincide with children making big developmental shifts which are more common in the baby and toddler phases, but even older children can hit bumps with their sleep.”

If you are struggling right now, infant sleep expert Katie Palmer, from Infant Sleep Consultants, suggests maintaining good sleep hygiene to get your child into the best position possible to navigate the next few months (and years, if you’re really lucky) of sleep disruption.

“This involves a good routine in the day, well-timed naps, a good bedtime routine and allowing your child to self settle,” she says. “They will always find this easier at the onset of sleep but if you know they can do it at the start of the night, there is no reason why they can’t for the rest of the night.”

The sleep specialist adds that if a child is going through a developmental leap, they may be more unsettled when it comes to drifting off – and if you’re finding this, you can help them by keeping familiar routines and boundaries in place.

Of course, there are certain points where a parent might think: is there something drastically wrong with my child because they literally do not sleep? And if you’re feeling that, it’s definitely worth speaking to a sleep specialist about it – or at the very least your GP.

If a child’s sleep is good enough most of the time – both in terms of quality and quantity – then sometimes just knowing that more challenging periods are biologically normal, and will pass, is all the reassurance parents need, says Peacock.

“All children will, sooner or later, reach the stage of sleeping through the night,” she adds.

But if a child isn’t managing well with the sleep they are getting – for example, if they are regularly tired and irritable throughout the day, or it’s taking hours to settle them at bedtime every night – that’s indicative of a more pervasive challenge with sleep rather than a short-term ‘regression’, she explains.

“Sometimes these challenges are underpinned by physiological aspects such as digestive discomfort or daytime naps not being optimal,” she says. “Other times, the patterns of behaviour that have developed around sleep aren’t helping a child to sleep well.

“The question really is whether things are working well enough, most of the time. If the answer to that is no, there are lots of ways that children can be supported towards better sleep.”