Sleep Regressions: A GP’s Guide to Every Stage

A lot of parents arrive at the phrase “sleep regression” already braced for it. They’ve read that one is due in four months, another at eight, another at twelve, and they’re waiting for it to land.

Sleep regression timetables are far less fixed than they look online. Some babies have a noticeably bad stretch around those ages, and plenty don’t; when it does happen, it usually arrives alongside a burst of development.

Broken nights are more normal than most parents expect. The NHS is clear that newborns wake repeatedly through the night for the first few months, and that sleep settles at very different rates from one baby to the next.

Sleep regression is more of a parenting term than a medical diagnosis, but I think it’s a useful way to describe something many parents experience. It refers to a period when a baby or young child who has been sleeping reasonably well suddenly starts waking more frequently, resisting bedtime or struggling to settle.

My hesitation is with the word itself. Calling it a regression suggests your child’s sleep development has gone backwards when in reality, the opposite is often true. These disruptions frequently coincide with periods of rapid development.

There’s some genuine developmental science behind the four-, eight-, twelve-, and eighteen-month stages, but the internet has probably made them sound far more predictable than they actually are.

Babies go through enormous changes in their sleep patterns during the first two years, and some of those changes do coincide with important developmental milestones. There isn’t strong scientific evidence, though, that all babies experience sleep regressions at four, eight, twelve or eighteen months. Some babies will have noticeable disruptions around those ages, others won’t, and both the timing and the duration vary enormously.

Around four months

At around four months, one of the biggest changes is that your baby’s sleep architecture is maturing. Their sleep is becoming more organised into different stages, and they may start waking more noticeably between sleep cycles. Surfacing between cycles is something we all do. It simply becomes more obvious at this age.

Around eight to ten months

At around eight to ten months, babies are often developing new motor skills, such as crawling, pulling themselves up and sitting independently. A baby who has just worked out how to pull themselves upright often wants to practice it at two in the morning. Separation anxiety can also become more apparent as babies develop a greater awareness of their caregivers.

Around twelve months

Around twelve months, some children begin to walk, their communication skills are developing quickly, and their daytime sleep requirements are changing. A nap that worked perfectly a month ago can quietly stop fitting, and that shows up at bedtime.

Around eighteen months

By eighteen months, toddlers are becoming increasingly independent. They’re developing language, asserting their preferences and may experience separation anxiety or resistance around bedtime. These are all normal and exciting developmental changes, but they can sometimes temporarily disrupt sleep.

Many periods of disrupted sleep improve within days or a few weeks, although some difficulties can last longer. There’s no scientifically established duration for a sleep regression, so I’d encourage parents not to worry if their child’s sleep doesn’t follow a particular timetable.

I’d encourage parents to look at the bigger picture rather than focusing on a particular number of weeks. Is your child otherwise happy, feeding well, growing normally and developing as expected? If so, a temporary period of disrupted sleep is usually nothing to worry about.

If it comes with other symptoms, that’s a different conversation, and the section below covers what to look for.

One of the most understandable reactions is to completely overhaul a baby’s sleep routine the moment things become difficult. Parents are exhausted and understandably desperate to find a solution, but constantly changing bedtime, nap schedules, or settling techniques can sometimes make sleep less predictable.

Overtiredness is the other one. Parents may try to keep a baby awake longer in the hope that they’ll sleep better overnight, but this can sometimes have the opposite effect.

What I’d generally recommend is maintaining a consistent, calming bedtime routine, responding to your child’s needs and avoiding unnecessary changes. That’s far less satisfying than a new plan, but it tends to work better.

Regular loud snoring, pauses in breathing, or gasping during sleep also warrant investigation. Those can be signs of obstructive sleep apnoea, which affects children as well as adults and is treatable once it’s identified.

If your child is struggling to breathe, has prolonged pauses in breathing, becomes blue or is unusually difficult to wake, seek emergency medical help rather than waiting for a routine GP appointment.

Months of broken nights take a real toll on parents, and that gets far less attention than it should. Parents should seek help if sleep deprivation is having a significant impact on their own physical or mental health, and that’s a reason to book a doctor’s appointment in its own right, rather than something to mention in passing at an appointment about the baby.

You don’t have to reach the breaking point before asking for support.

Persistent exhaustion, low mood or difficulty coping shouldn’t automatically be dismissed as simply part of having a baby. Chronic sleep deprivation can take time to recover from, but these symptoms can also have other causes, including postnatal depression. If you’re struggling, please speak to your GP or health visitor.

Consistency applies to where your child sleeps as much as when. Changes in the environment are one of the things that can disrupt sleep at any age, so if a move out of the cot is coming, it’s worth doing it as one change on its own rather than alongside a house move, a new nursery or a fortnight of teething.