As little as I knew about breastfeeding before having kids, I probably knew even less about infant sleep! Who knew it was so complicated and ever changing? Suffice it to say that sleep is the parenting topic with which I’ve been most obsessed. Even though Charlie is 2 years old now, I’m still obsessed!

These are some interesting and surprising things I’ve learned about baby sleep since Charlie was born:

Newborns
- Newborns have a startle or “moro” reflex that causes their arms to twitch the first couple of months. Because of this reflex, newborns sleep better when swaddled.
- Newborns’ circadian rhythms are not fully developed so they often have their days and nights mixed up.
- Expose your newborn to light, sound, and play during the day, and dark, quiet and as little stimulation as possible at night to help set their circadian rhythm.
- It takes newborns at least 20 minutes to enter a deep sleep, which is why they’re asleep in your arms but wake up as soon as you put them in their crib.
- Ways to get your newborn to sleep include: rocking, patting, wearing, strolling, nursing/bottle feeding, pacifier, swing, bouncer, car ride, playing loud white noise (vacuum, hair dryer), bouncing on an exercise ball.
- Colic doesn’t exist in some cultures where moms wear babies and breastfeed them nonstop throughout the entire day.
- Putting your baby in the crib drowsy but awake gives them opportunities to learn how to self soothe, put themselves to sleep, and not rely on an external sleep prop to fall asleep.

Naps
- Babies are most tired before their first nap of the day so this is their shortest awake period.
- Set consistent nap routines so your baby knows it’s nap time.
- The length and quality of daytime naps affects night time sleep.
- Some babies 6 months and older do well on a 2-3-4 hour schedule. (Charlie definitely couldn’t stay awake that long.)
- Most babies drop their fourth nap by 5 months. (Charlie dropped his at 5 months.)
- Most babies drop their third nap by 9 months. (Charlie dropped his at 9 months.)
- Most toddlers drop their second nap by 18 months. (Charlie dropped his at 15 1/2 months.)
- Napping in a stroller or car seat is not as restorative as napping in a crib.
- Sometimes reducing daytime naps can increase night time sleep (if your baby is still getting enough sleep in a 24 hour period).
- Don’t let your baby nap too late or it may interfere with night time sleep.
- Babies have a 45 minute sleep cycle, which is why many wake up after 30-45 minutes into a nap.
- The 90 Minute Baby Sleep Program works great for some babies – Eat, play, and put your baby to sleep by 90 minutes of awake time.
- Babies under 6 months of age have a maximum awake period of 2 hours; for many babies 4-6 months it’s much less than 2 hours, and for babies under 4 months the awake periods are even less.
- Put babies down for naps at the first signs of tiredness, or within a designated time frame like the 90 minute sleep program to prevent overtiredness.

Night time Sleep
- Babies sleep better and longer when they go to bed earlier (before 8pm… even as early as 5:30pm).
- Children should wake up around the same time everyday to set their internal clock.
- A consistent bedtime routine like a bath + lotion + pjs lets your baby know that it’s bedtime.
- Many moms wake their babies up for a “dream feed” around 10-11pm to encourage their babies to sleep longer at night.
- By 6 months, most babies are physically capable of sleeping 10-12 hours straight at night.
- Sometimes babies that wake up for middle of the night feedings are doing so out of habit — they get hungry at that time because they’re used to eating at that time.
- Children have a strong shift in their sleep cycle around 4:30am, which is why so many of them wake up at this time.
- Early morning wake-ups are one of the most difficult sleep problems to solve.
- Make sure your baby gets enough calories in the daytime so they’re less likely to wake up for night time feedings.
- If wet diapers don’t bother your baby, don’t change them in the middle of the night as it will stimulate them.
- Even making eye contact with your baby at night can stimulate them.

General Sleep
- All babies are different. Different things work for different babies, and some are better sleepers than others.
- Consistency is key no matter what sleeping methods you use.
- Often fussiness, tantrums and sleep problems are related to being overtired and/or not getting enough sleep.
- Once a baby is overtired, adrenaline kicks in and it’s much more difficult for them to fall asleep.
- Tired signs include yawning, getting quiet, staring off in space.
- Overtired signs include fussiness, eye rubbing, looking wired.
- Sleep props are when a baby relies on an external force – rocking, nursing, stroller – to fall asleep.
- An eat, play, sleep schedule ensures that babies do not fall asleep nursing/taking a bottle.
- Developmental milestones such as rolling over, crawling, growth spurts etc. often affect sleep.
- Sleep begets sleep.
- White noise and black out shades often help lengthen naps and night time sleep.
- Give your baby a chance to fuss and settle down instead of picking them up as soon as they start making noise.
- Babies generally sleep better on their stomachs (but you shouldn’t put them to sleep on their tummies… they will eventually roll over and do it on their own).
- Babies fall asleep better in a cooler room (less than 72 degrees).
- Many babies experience a sleep regression at 4 months because they’re going through so much developmentally. (Charlie did because he started rolling over in his crib.)

I think sleep training is a whole different beast, so I’ll write a separate post on that. Even having studied so much about baby sleep, it’s still a mystery to be solved for me. Olive has been sleeping better the past couple of nights, but when it comes to baby sleep, as soon as you think you have it figured out, it completely changes on you again.

What interesting or surprising things have you learned about baby sleep?