How long does the 8 month sleep regression last?

Usually somewhere between two and six weeks. It tends to ease as the new skill becomes ordinary: once crawling or standing stops being thrilling, babies stop practising it at 2am. If it drags on well beyond six weeks, look at daytime sleep and wake windows before assuming it is still the regression.

Is the 8 month sleep regression real?

The name is informal, but the pattern is real and well known. Several big developmental changes cluster around this age, and disrupted sleep is a common side effect of all of them. It is less a single event than a few things arriving at once.

Why does my baby stand up in the cot and cry?

Because they have learned to pull up to standing but not yet how to get back down. It is very common and genuinely distressing for them. Practising lying down from standing during the day, guiding their hands down the cot bars, shortens this phase noticeably.

Is it separation anxiety or the regression?

Often both. Separation anxiety tends to show up as crying the moment you leave, clinging at bedtime, and settling quickly once they see you. Motor practice looks more like a baby who is wide awake, rolling, crawling or standing, and not especially upset about you.

Should I move my twins into separate rooms?

If one twin's night practice is waking the other every time, separating them for a couple of weeks is a sensible short-term fix, and most twins go back to sharing without trouble once the phase passes. It is a temporary measure, not a decision about the long term.

Should I drop to two naps?

Many babies drop the third nap somewhere between 7 and 9 months, and the transition itself can cause a few rough weeks. Let the third nap go when it is consistently refused rather than forcing it, and bring bedtime a little earlier while the day adjusts.

The 8 month sleep regression, and twins

For a few weeks it was good. Maybe really good. Two naps, or three, a bedtime that stuck, a night with one feed or none. Then somewhere around eight months, without anything obvious changing, it went. Now there is a baby standing in the cot at 3am, delighted with themselves, or a baby who screams the second you put them down and stops the second you pick them up.

This is usually called the 8 month sleep regression, and it is one of the more predictable things in the first year.

Three things arrive at once

Unlike the 4 month change, which is one thing (sleep cycles maturing), the 8 month regression is several developments piling up in the same few weeks.

Movement. Crawling, pulling up to stand, cruising along furniture. These are enormous skills, and a baby's brain rehearses new motor skills during light sleep. So they wake, and the first thing they do is practise. Getting onto hands and knees in the cot is not a baby who cannot sleep. It is a baby who is too busy to.

Separation anxiety. Around this age babies start to understand that people exist when they cannot see them, which sounds lovely and is, but it also means they know you have gone. Being put down and left becomes something to protest. This often shows up hardest at bedtime and after night wakings.

Nap changes. Many babies move from three naps to two somewhere between seven and nine months. Transitions like that tend to make the day a little too long or a little too short for a while, and an overtired baby sleeps worse at night, not better.

Any one of these would disrupt sleep. Together they explain why so many parents describe it as a switch being flipped.

How long it lasts

Usually between two and six weeks. The motor practice fades once the skill stops being new, and separation anxiety eases as your baby learns, night after night, that you do come back. Neither of those can be hurried, which is frustrating, but it also means the regression tends to end without you needing to fix anything.

What actually helps

Keep the routine you already have. This is the single most useful thing and the hardest to stick to at 3am. Whatever your bedtime looks like, keep doing it. The regression ends faster in babies whose evenings stay predictable.

Practise the new skill in daylight. If your baby is pulling up and getting stuck, spend a few minutes each day showing them how to come back down, hands down the bars, knees bent. It sounds almost too simple. It works.

Protect daytime sleep. A baby who arrives at bedtime overtired has a worse night. Watch the wake windows, which at this age are usually around two and a half to three and a half hours, and bring bedtime forward a little if naps have been short.

Respond calmly and briefly. At night, go in, reassure, lie them back down, and keep it dull. Low light, few words. You are showing them that nothing interesting happens after dark.

Be careful about new habits. It is tempting to bring back whatever worked at three months: feeding to sleep, rocking, bringing them into your bed. None of those is wrong, but anything you start now you will probably have to stop again in a month. If you choose to do it, choose it on purpose.

With twins, it is rarely a shared phase

One of the more useful things to know is that twins almost never go through this at exactly the same time. Motor milestones in particular can be weeks apart, even in identical twins, and one twin's separation anxiety might be mild while the other's is intense.

So a lot of what feels like two babies regressing is actually one baby regressing and waking the other. That is a different problem with a different fix.

If they share a room and one twin's 3am practice session keeps waking the other, separating them for a couple of weeks is a perfectly reasonable temporary measure. Most twins move back in together without any fuss once the phase has passed. It is not a permanent decision.

It also helps to write down who woke first. After a week the pattern is usually obvious, and it changes what you do: if it is always the same twin, that is the one to focus on, and the other one mostly needs protecting from the noise.

When to get advice

A regression is a phase in an otherwise well baby. Talk to your health visitor or GP if the waking comes with a fever, pulling at the ears with signs of illness, a rash, noisy breathing or snoring with pauses, or if your baby seems unwell during the day as well as at night. And if it goes on well past six weeks with no sign of easing, it is worth a conversation.

The part to remember

It feels like a step backwards. It is actually a sign of everything going right: a baby learning to move, learning that you are a separate person, learning to sit in a longer day. Sleep takes a knock while all of that settles in, and then, for most babies, it comes back.

The 8 month sleep regression: why a good sleeper suddenly stops (and what to do)