The Science Behind Baby Sleep: Understanding Your Baby's Sleep Needs

Ashli Daley, RN, CPST, Lactation & Infant Sleep Expert

This blog was written in paid partnership with Dr. Brown's.

Being a caretaker often means chasing after the one thing your child seems determined to avoid: sleep! Understanding sleep science can help set realistic expectations and create a foundation for healthy sleep habits. Let's explore why sleep is crucial for your baby's development and how routines can help your little one become a sleep champion.

Demystifying Sleep Cycles: How Newborns Sleep Differently

Newborns are tiny sleep machines, averaging 16-18 hours a day. However, unlike adults, their sleep is fragmented into short cycles (around 40-60 minutes) with frequent wakeups. This is because their circadian rhythms, the internal clock that regulates sleep-wake cycles, are still developing. Unlike adults who cycle through stages of deep sleep, light sleep, and rapid eye movement (REM) sleep throughout the night, newborns spend most of their sleep time in a state called active sleep. This might look like they're awake, with little grunts, wiggles and even eye movements. Don't be fooled! This active sleep is crucial for brain development and memory consolidation.

Sleep Needs by Age

Finding Your Baby's Sweet Spot: Wake Windows and Sleepy Cues

Wake windows refer to the amount of time your baby can stay awake comfortably between naps and bedtime without becoming overtired. There's a sweet spot! Keep one eye on your baby to learn their sleepy cues (e.g. yawning, fussiness, eye rubbing), and one eye on the clock to determine their ideal wake window. If it takes your baby longer than 15-20 minutes to fall asleep, it might be a sign they need more awake time. Conversely, if they fall asleep in under 5 minutes, they may have been put down too late and could benefit from a slightly shorter wake window. Here's a guide to start with:

• 0-8 weeks: 45-60 minutes
• 8-12 weeks: 60-90 minutes
• 3 months: 1-1.5 hours
• 4 months: 1.5-2 hours
• 5-7 months: 2-3 hours

The Dangers of Overtiredness

An overtired baby is often a cranky baby! When a baby is past their ideal wake window, they become fussy, fight sleep and experience more frequent nighttime wakeups. This can create a vicious cycle of exhaustion for both you and your little one.

The Importance of Routines: Setting Your Baby's Internal Clock

While babies and young children can't tell time, routines become their way of understanding the world, and what to expect next. Consistent sleep routines (for both naps and bedtime) signal to your baby that sleep is coming. This predictability helps them wind down, fall asleep easier and sleep longer.

Sleep Routines by Age

Creating a Sleep-Promoting Environment

• Darkness: Darkness promotes melatonin production, the sleep hormone. Use blackout curtains and a dim nightlight for overnight feedings.
• Temperature: Aim for a cool room (around 68-72°F) for optimal sleep comfort.
• White Noise: A white noise machine can block out distractions and create a calming atmosphere.

Beyond the Basics: Addressing Sleep Challenges

Newborn and infant sleep can be unpredictable, and even with the best routines in place, there will be nights when your little one struggles to stay asleep. Here are some common challenges that can disrupt sleep, along with solutions to help you and your baby get the rest they need:

• Feeding troubles: A gassy tummy or uncomfortable reflux can make it difficult for a baby to sleep soundly. If your baby appears to be suffering from either, consider asking your pediatrician about a feeding assessment to rule this out as the cause of sleep disruptions.
• Teething: Teething pain can be a disruptor for sleep, but it often doesn’t last long. Offer a cool teething toy for your baby to chew on, like the Dr. Brown's AquaCool Water-Filled Teether, which can be placed in the refrigerator for cooling and safe soothing for all areas of baby’s mouth. Teething rings, like the Dr. Brown's Flexees Friends Teether, made from silicone or other natural materials can also be effective. Over-the-counter pain relievers may be appropriate for older babies, but always consult your pediatrician first.
• Developmental milestones: As your baby reaches new developmental milestones, like rolling, crawling, or pulling to stand, they may find practicing these skills in their crib more fun than sleeping. As their brain stores this new skill, we see more time spent in REM sleep, making it harder for them to settle down or stay asleep. These sleep disruptions, often known as "regressions," are periods of developmental progression and can last anywhere from 7-10 days. To help, give your baby plenty of time during the day to practice their new skills and keep your sleep routine consistent.
• Separation Anxiety: As early as 4 months of age, babies can start to experience separation anxiety, making nighttime wakeups more frequent. They may cry out for reassurance or seem hesitant to fall asleep on their own. Respond promptly to your baby's cries and offer them reassurance in their sleep space. The goal is to comfort your baby without creating a playtime association with nighttime wakeups.
• Hunger: This might seem obvious, but a hungry baby won't sleep well. If your baby wakes frequently at night, especially in the early months, it could be a hunger cue. Consider offering a feeding, by breast or bottle, to see if that helps them settle back down. Once your baby is over 4 months, try soothing before offering a feed.

Remember that every baby is unique, and what works for one may not work for another. Be patient, experiment with different strategies and don't hesitate to seek professional help if sleep challenges persist. Understanding sleep science and establishing routines can empower you to create a healthy sleep environment for your baby. With a little patience and consistency, both you and your little one can enjoy a good night's sleep!

Disclaimer: The information provided on this blog is for informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified healthcare provider with any questions you may have regarding a medical condition or health concern. Never disregard professional medical advice or delay in seeking it because of something you have read on this blog.