Newborn sleep architecture and sleep cycles

These can be predictable, or unpredictable and both are normal. Your baby might sleep for one sleep cycle (45 minutes) for his morning nap, and then easily have 2 sleep cycles later in the afternoon. Science tells us that this is normal, as sleep architecture can be variable from day to day. Wondering why your baby will only sleep for 45 minutes in the morning, but will happily sleep for 1.5 hours in the afternoon is going to cause you stress, instead look for those patterns and know that if your new-born wakes up happy after a sleep, whether its 45 minutes or 1.5 hours, he has probably …..

  1. Had enough sleep

  2. Is happy to have a quiet rest and put himself back to sleep shortly

  3. Or wasn’t awake long enough to need any more sleep than 45 minutes

Your babies 45 minute power nap has reduced the sleep/wake homeostat enough that they don’t feel such a powerful drive to sleep anymore, but this drive might build enough that they need a longer sleep later on in the day.

Watching your baby will let you know whether they need more sleep than they are getting, or are happy with the amount of sleep they have. If they wake up crying from a 45 minute sleep they are either.

  1. Hungry – try feeding them and seeing if they then want to be awake or finish their nap

  2. In pain from wind or reflux, try picking them up to burp them or cuddle them and then see if they are happy to be awake or try to go back to sleep. (Rubbing their face into your shoulder is often a sleep cue new parents miss here).

  3. Still tired and want to be asleep but have woken for some reason. Try adjusting their swaddle so they are snug, turn their white noise back on and try to re-settle with a rock, or a pat or a jiggle.

Over time this will become more regular and predictable.

The sympathetic nervous system is the part of the autonomic nervous system which responds to stress. It prepares the body to cope with stress by producing stress hormones like Noradrenaline, cortisol and adrenaline these increases your heart rate and breathing rate and prepares your body to fight or fly. If these situations of stress occur frequently for your baby, they might be finding it difficult to fall asleep, and understandably so!

Their parasympathetic nervous system is not yet developed, this is the part of the nervous system which allows the body to calm down the sympathetic nervous system, so when you become stressed, you can calm yourself down or self soothe. Your new-born can’t physiologically do this yet. They are looking to you to be their calmer, and help them get to such a calm state that they can go to sleep.

With this knowledge we can see why babies who are in pain from reflux or colic are so much harder to settle than babies who are not, as their sympathetic nervous system is working in over drive and inhibiting the ability to sleep. The solution is to physically soothe them and help them calm down and then get off to sleep.

Similarly this is why we don’t use cry it out on new-borns, this would only serve to stress your baby and trigger this stress response by the sympathetic nervous system and inhibit their ability to sleep. Until the ability to self soothe is developed, we need to offer assistance to calm, and get off to sleep.

Things which we know help to calm this central nervous system when it’s stressed, or turn on the calming reflex…..

  1. Holding

  2. Sucking/feeding/dummies/fingers

  3. Patting

  4. Rocking

  5. Walking

  6. Jiggling

  7. Skin on skin

  8. Massage

  9. Swaddling

  10. Side settling

  11. White noise

When your baby is hungry their sympathetic nervous system switches on, this over rides your babies drive to sleep. So essentially hunger has woken them up. To calm this state of stress, you need to feed your baby. If this is mid nap or middle of the night, feeding your baby will be the fastest way to calm them down and figure out if they are hungry or ready to be awake.

You don’t need to try to force 3-4 hourly feeds on your new-born by holding them out. Our routine examples, have feeds 2-3 hourly, with top ups and split feeds as examples of ways to ensure your baby is not hungry and is going to sleep with a full tummy. If your baby is crying before you feel a feed is “due” they are probably hungry and a quick feed will be the least stressful option.

If you feel your baby is feeding 1-2 hourly around the clock for a pro-longed period of time, speak with a lactation consultant to check if their latch is correct or if there is anything which needs to be addressed.

Need help with your newborns sleep? Speak with the experts!