5 Things I Wish I Knew Sooner About Infant Sleep

My understanding of infant sleep has changed so much over the years.  After my first was born, I knew absolutely nothing about infant sleep, and I regularly relied on information on the internet about schedules and wake windows.  All of the information out there about what I "should" be doing or how my baby "should" be doing caused me so much stress and anxiety.  So, here are 5 things I wish I knew sooner about infant sleep. 

1) It is normal for older babies to wake at night

If you google when will my baby sleep through the night, you will be inundated with organizations and sleep consultants telling you that your baby "should" be able to sleep through the night between 4-6 months.  After my first, seeing that was absolutely heartbreaking.  I felt like something was wrong with my baby and wrong with me.  Guess what?  That is just not true!  Six percent of babies aged 6 months reliably sleep through the night.  Six percent!  And, that is counting a 6 hour stretch as sleeping through the night.  Six hours is a far cry from the 11-12 hours that some people say babies should be sleeping without waking at that age.  That same study found that there is so much variability between babies AND variability between nights.  For example, a baby might sleep a 6 hour stretch one night, but then not sleep a six hour stretch again for a few days. 

On average babies aged 6-18 months wake 1-3 times a night.  It is normal for babies to wake up at night to get needs met.  They may be hungry, thirsty, hot, cold, uncomfortable, etc.  A baby's needs do not stop after 8pm.

2) Optimal sleep latency is 15-20 minutes

Sleep latency is the amount of time it takes for somebody to fall asleep.  Did you know that there is an optimal amount of time that it should take people to fall asleep?  The optimal sleep latency is about 15-20 minutes.  How long it takes a baby or your child to fall asleep can give us a clue as to what is going on with their sleep needs.  If a baby is waking frequently, it also may explain why.

We often say that it is a good thing for kids to fall asleep quickly.  I know that I get really excited when my kids fall asleep right away.  However, falling asleep too quickly is a sign that there is some sleep deprivation, and it may actually lead to a poor night's sleep.

If a baby or young child falls asleep under about 10 minutes, it is a sign of sleep deprivation.  Under 5 minutes, there is probably severe sleep deprivation and if it takes 5-10 minutes, there may be a troublesome sleep deprivation.  While 15-20 minutes is ideal, 10-15 minutes is manageable and sleep deprivation is probably not an issue.  What if it takes longer than 20 or 25 minutes to fall asleep?  If it is taking a really long time to fall asleep, it may be due to anxiety in children and adults or poorly timed sleep in babies/young children.  For example, if there is not enough time between the last nap and bedtime, that may lead to prolonged sleep latency.

Parents often describe bedtime as "easy" if a baby or young child falls asleep quickly.  However, that can lead to problems with the architecture of sleep - how the night is structured with transitions between the 4 stages of non-rapid eye movement (NREM) sleep and rapid eye movement sleep (REM).  When babies and young children fall asleep very quickly due to sleep deprivation, they tend to skip the earlier stages of NREM sleep and go right into the later stages.  Because of that, they may have a harder time transitioning between between sleep cycles, wake frequently, and need support falling back asleep. 

Luckily, once the sleep deprivation is corrected through optimizing naps and the timing of sleep, the sleep latency lengthens to 15-20 minutes and the baby/young child has an easier time transitioning between sleep cycles .

3) Sleep pressure can influence both falling and staying asleep

Sleep pressure can influence both falling and staying asleep.  Sleep pressure is a homeostatic function regulated by the level of adenosine in our brains.  This is separate from our circadian rhythm.  The level of adenosine in out brains rises the longer that we are awake.  Sleep pressure has to build up to both initiate and maintain sleep.  In newborns and younger babies, the awake interval that allows enough sleep pressure to build up is very short.  That awake interval lengthens as a baby gets older.  So, if a baby has a very long sleep latency, there may have not been enough awake time before bedtime to build up that sleep pressure.

Not only does sleep pressure influence falling asleep, but it influences staying asleep as well.  Babies can have something called a "split night" which seems to be most commonly caused by insufficient sleep pressure. 

A scenario that I commonly with babies or young children is when they take a short and late nap.  Because the nap is short, the baby is acting very tired early in the evening, so parents push up bedtime.  Because the amount of daytime sleep was so much less than what the baby needs, they are able to fall asleep.  However, because there was not a lot of time in between waking from the nap and bedtime, there is not enough sleep pressure built up to maintain sleep.  So, the baby may be wide awake in the middle of the night for hours.  When a baby is awake due to insufficient sleep pressure, they are usually very happy to be awake, and they may want to play! 

Fixing timing of naps and bedtime can stop those disruptions in sleep due to insufficient sleep pressure. 

4) Sleep needs differ from baby to baby

Just like adults, babies and young children have different sleep needs.  This is one of the reasons why adhering to a schedule found on the internet can be detrimental to your baby's sleep and super frustrating for you.  Some babies need less than what is described for each age and some babies need more.  There are also babies that do better with several shorter naps than less frequent long ones.  As long as overall sleep needs are met without signs of overtiredness, that is ok!  In fact, it may be more detrimental to try and "force" baby into longer and less frequent naps. 

Sleep also matures at different rates.  For example, some time between 3-6 months, the sleep cycle matures.  That time of sleep cycle maturation can cause sleep disturbances.  Those sleep disturbances are what people commonly refer to as the dreaded 4 month sleep "regression".  However, that doesn't happen at the same time for every baby.  While many people expect it at 4 months, it occurs at any time in between 3-6 months.  This happens all throughout infancy and toddlerhood.  Common times of sleep "regressions" are 4,8,12, and 18 months, but again they don't happen at the same time for every baby.  For example, my toddler went through a period of really poor sleep that commonly happens at 18 months at closer to 20 months - and that is normal.  It is important to look at every baby as an individual with different sleep needs and rate of sleep development. 

5) There is no one size fits all approach to infant sleep!

Just as not every baby has the same sleep needs, there is no one size fits all approach to infant sleep.  The most important thing is to find an approach that works for you and your family.