Must-Knows for Surviving the 4-Month Sleep Regression

If your baby is between 3-5 months old and suddenly hit a major rut with sleep, you’ve likely hit the dreaded 4-month sleep regression. New night-wakings, even as often as every 1-2 hours, waking up 40 minutes after bedtime, and cat-naps galore are all tell-tale signs. So what the heck is going on? And, more importantly, how do you survive?

The 4 -month sleep regression is actually a misnomer. Although it feels like a huge step backwards in sleep, it is actually a developmental milestone that marks a progression in your baby’s brain development. During this period of sleep disruption, their brains are going from a newborn sleep pattern to an adult-like sleep pattern. This matters significantly because:

  • Their circadian rhythm is now very much in-play and in rhythm with the sun, meaning they will need an earlier bedtime now and will likely start waking with the sun;

  • Biological nap windows become much more important (the optimal times of day for nap sleep);

  • Their sleep cycle length changes from 4-6 hours to 2-4 hours. They will be spending much more time in light sleep phases.

The last one is probably the most important in terms of the effects on their sleep. A baby that may have been doing a long 6-hour stretch at 3 months might now be waking up every 2 hours! They will need assistance getting to deeper sleep phases more often. What worked in the newborn stage often quickly becomes unsustainable.

Is it a growth-spurt? Some parents are tempted to think that the frequent wake-ups are because of a growth spurt, so they start feeding at every wake-up. But this unfortunately only reinforces the problem as your baby is likely using those feeds to get himself back to sleep, rather than for nourishment. Although a growth-spurt can cause an extra wake-up overnight, it will not cause the need to eat every 2 hours (for a healthy, normal sized 4-month old).

The 4 -month sleep regression is actually a misnomer. Although it feels like a huge step backwards in sleep, it is actually a developmental milestone that marks a progression in your baby’s brain development.
— lindsey at sleep little lamb

Why is the regression worse for some babies than others? There are certain things that can make the regression worse – a baby who is already overtired from short naps or a too-late bedtime, will often hit the regression hard. Also, a baby who is not on any sort of schedule and has a lot of sleep props (must be bounced/rocked/nursed to sleep, etc.) will also often have the hardest time during the regression.

Can you prevent the 4-month regression? No, it’s not possible for baby to skip this developmental stage, but there are certain steps you can take to help minimize the negative effects on sleep.

1)     Establish healthy hygiene before it hits. This means following age-appropriate wake-times, a consistent nap and bedtime routine, and an optimal sleep environment.

2)     Encourage a healthy schedule. Even during the newborn stage, you can start following a flexible schedule for sleep and feeding, that includes full feeds, age-appropriate wake-times, and as they get older, an earlier bedtime.

3)     Work towards independent sleep. Give your baby opportunities each day to work a little bit on self-settling. This means not responding to them the second they wake-up and fuss if it’s not time for a feed- give them 5 minutes to see if they’ll resettle. This is a great time to start sleep training!

What if the regression has hit and you haven’t done anything to prevent it? Don’t worry! Now is a great time to start implementing the above suggestions. The prevention is almost the same as the cure: Healthy sleep hygiene, optimal sleep environment, age-appropriate schedule. If you need the cure, you’ll need to add in choosing a sleep training method. (For help with this, check out my 45-minute assessment call and baby sleep packages.)

How long does it last? It’s different for every baby, but it will usually pass within 2-4 weeks. If your baby’s sleep is still disrupted after several weeks, you can safely assume it is not still the regression. More likely something else is off in the sleep plan. But you don’t have to wait 4 weeks to start implementing positive changes. In fact, implementing positive sleep changes now will help them pass through the regression much more quickly.

For personalized, professional help with navigating this challenging time, book your free sleep call here.


Lindsey McGonegal