'Sleep Regression'... two words that are guaranteed to strike fear into the hearts of most parents! However, instead of seeing the word 'regression' make sure you see the word 'progression' as that is EXACTLY what this is. I'll start with the most infamous of all the progressions...
The Four-Month Regression
You may have previously had a baby sleeping through the night with one or two wakings and a dream to lay down for their daytime naps up until this point- this frustrating process is more commonly referred to as the 4-month sleep regression. Whereas before your baby had fallen quite easily into a deeper sleep state and stayed asleep in previous months the sleep regression refers to the sleep cycle becoming mature, more like that of an adult -or older child.
At 0-3mths your baby's sleep cycle would have been around 30 minutes in length, which would have looked like REM-DEEP SLEEP-REM. They would have dropped off to sleep nice and easily in your arms or in their moses basket and sleep was just sleep- simple! But not anymore...
This means your 4 month old baby will now have distinct stages of sleep with a sleep cycle of around 45 minutes opposed to 30 minutes and they will now have to go through light/active sleep to enter deep sleep. This sometimes causes tears and grizzling as it is harder for a baby to fall asleep but much easier with practise, positive sleep cues, a predictable routine, and simplifying the approach to nap put down.
The Eight-Month Regression
This is less of a sleep regression, more of a cognitive leap. Sleep becomes affected because in simple terms baby is becoming more active and using more of their brain space to practise crawling, babbling, sitting up and standing at all sorts of hours during the day and the night. Baby will seemingly be in the wide-awake club in the middle of the night with no signs whatsoever that they are going back to sleep! Given time they will drift back and intervention here is usually unnecessary.
Babies can be up randomly at night for anything from 20 minutes to 1hr at a time often anywhere between the hours of 1-5am when REM sleep is prevalent. I often have worried calls from Mums at around 2/3am saying 'I was fast asleep and just glanced at the monitor and he/she is sitting there just staring into space rocking side to side, what shall I do?!' This is completely normal, albeit it looks a bit eerie on the monitor! The answer is unless they are distressed leave them to it. If they are crawling round their cot happily or just sitting they will eventually go back to sleep on their own. Our presence here can sometimes be counterproductive and we can rouse them from a sleep they may go back into on their own.
The 18- Month Regression & Toddler Sleep
The 18 month regression is yet another developmental change and leap forwards. You may find when you put your 18 month old down to sleep at 7pm that they do not go to sleep like they used to in months gone by. You will find them 'downloading' the words they have spoken during the day, singing songs and re-playing scenes from the day! There is not much you can do here other than make sure that they safety see themselves to sleep. Don't fall into the trap of putting them to bed later. If you are concerned that they are having too much daytime sleep then this can be cut down to around 60-90 minutes (60 minutes being the minimum in an case and never past 3pm).
Toddler sleep regressions are much more to do with any change in their little lives. This could be moving nursery classes, starting pre-school, having a new sibling, a change in family situation, moving house and so on. They can come on suddenly and out of nowhere. Very commonly this happens after a family holiday, for example....If your child spends a lot of their waking hours at nursery/with a nanny then their routine is really 'set', they know when they see you and compartmentalise their behaviour on Mummy & Daddy days and on Nursery/Nanny days. So, you all go on holiday you have that wonderful cherished time together but the flip side of this can be some separation anxiety when you are back at home. Toddlers can start to resist bedtime and start waking through the night having previously been great sleepers. If this happens on your arrival home it is really important to validate your child or toddlers feelings during the daytime and offer reassurance at night wakings but remembering to also leave at the end of this reassurance. Offering lots of love cuddles and praise during waking hours and keeping your bedtime routine really straight forward and calm is helpful. Leaving your toddler in their room to sleep post holiday on night one can often become upsetting for them, it is at this point we have to take care and nuture their emotional security. You may have to give them the benefit of the doubt and stay with them a little while longer (holding hands for example with no other interaction) whilst they drop off to sleep for a temporary period (I'm talking two or three nights) whilst they get back in the saddle. It is important this is short lived and brief so as not to create a long-term lingering bedtime!