Infant Sleep Update: Why Young Babies “Mix Up” their Days and Nights

by Jennifer Goldbronn, MAS, RD

Today, we will talk about how light/dark cycles affect how babies sleep at various ages. Understanding how these cycles affect babies' sleep patterns will help you understand yet another reason why newborns wake up so often during the night. (Peirano 2003)

In adults, sleep and wake time is regulated by 2 internal “clocks,” one that responds to the light/dark cycle and one that is based on a need for sleep that builds up during the waking hours. The clock that responds to the light/dark cycle is located in the brain and uses hormones to regulate activity and sleep over each 24 hour period. This system is called the “circadian rhythm.” Circadian rhythms are not functioning in newborns and that is a good thing because newborns need to wake both day and night for care and to be fed enough to grow well and stay healthy. (Peirano 2003)

When Circadian Rhythms Develop: “My baby has his days and nights mixed up!”

You may have heard about (or experienced!) erratic newborn sleep patterns. It seems that newborns have their days and nights “mixed up.” It’s true! A young baby’s sleep patterns do not follow the light/dark cycle (awake during the day, sleeping at night) like adults’ do. Babies’ sleep patterns don’t start to follow light/dark cycles until about 6 weeks of age, and circadian rhythms are not fully developed until 12 to 16 weeks. This does not mean that you should expect your baby to sleep through the night at 16 weeks. It means that you’ll start to see a clear pattern of wakefulness during daytime hours and a longer stretch of sleep during the night by the time your baby is 12 to 16 weeks old. (Peirano 2003, Heraghty 2008)

While you can’t do anything hurry this process, there are a few things that may influence how quickly your baby develops circadian rhythms after the first 6 weeks. Type of feeding (formula-fed vs. breastfed), environmental lighting (lights on in house in the evening hours), and infant age all can affect the development of your baby’s circadian rhythms. One study found that breastfed infants, 1st born infants, and girls developed circadian rhythms earlier than other infants (but there was still a broad range of 8-16 weeks). (Mirmiran 2003)

How to Work with Your Babies’ Natural Rhythms

Here are a few things you can do to work with (instead of against) your baby’s natural rhythms.

1. Keep the room where your baby sleeps dark at night. When your baby wakes during the night, keep the lights low when taking care of his needs, such as feeding or diaper changes.

2. Expose your baby to natural light during the day.

3. Follow a consistent bedtime routine that includes slowing things down in the evening, including lowering the lights and noise level.

The first 6-weeks of your baby’s life are especially challenging; learning about your baby’s sleeping and waking patterns can help you understand why your young baby may seem like he doesn’t follow a consistent “schedule.” You are going to need help during those weeks when you are most sleep deprived yet need to take care of your other responsibilities. Your baby eventually will learn that nighttime is for sleeping. Until then, here are some past posts to help you deal with the inevitable sleep deprivation you will experience while your baby needs so much nighttime care.

Can Little Changes Lead to a Little More Sleep? 
Thoughts from a Sleep Deprived Mom
Tips from the Trenches: Surviving Sleep Deprivation
Weighing the Pros and Cons of Napping

References

Peirano P, Algarín C, Uauy R. Sleep-wake states and their regulatory mechanisms throughout early human development. J Pediatr. 2003;143:S70-9.

Mirmiran M, Maas YGH, Ariagno RL. Development of fetal and neonatal sleep and circadian rhythms. Sleep Medicine Reviews. 2003; 7 (4): 321-334.

Heraghty JL, Hilliard TN, Henderson AJ, Fleming PJ. The physiology of sleep in infants. Arch Dis Child. 2008;93(11):982-5.

Tips for Dealing with a Waking 9-Month-Old

Last time, we shared some reasons why a 9-month-old may wake and refuse to go back to his crib. In this post, we promised to share some tips to help the tired parents with older infants. Some of you may be expecting us to produce sure-fire ways to get that baby back into the crib, sleeping through the night - sweetly, quietly with no tears or stress. Well...most of you will know that we can't do that, because we tell you the truth.

Our reader asked:
"My 9-month-old often refuses to let my husband put him back in his crib at night. I have to go in and nurse him every time he's up in order for him to go back to bed and sometimes even then he doesn't want to go back in his crib!"

Since the beginning of our blog, we've had many posts about sleep. You can read through some of them by clicking here. These posts always seem to attract strong opinions and we realize that each family manages the night time hours in their own way. For some of our readers, "sleep training" may seem to be the logical answer to a baby's refusal to go back to sleep. We've already shared our reasons why that would not be our first choice. Other readers would tell any mom waking with an older infant to sleep with the baby. You may have noticed that we haven't talked about co-sleeping, which the American Academy of Pediatrics opposes. Co-sleeping is both a simple act and a complicated issue and we believe that others are better at examining the pros and cons of that practice and that our readers can make their own informed decisions. So, we'll stay focused on understanding, and working with, the baby's behavior (that's what we're here for after all).

It is important to understand that it is not unusual at all for a 9-month-old to wake once at night. Many mothers find the infrequent night nursing is fine for them, others search for ways to phase the night nursing out of their lives. This is a process that takes a little time.

Some ideas:

1. We're going to assume that this baby is growing well, feeding well, and not showing any hunger cues when he wakes at night. Growth spurts can cause babies to feed more frequently for a few days (even at night) so you might want to give it some time and see what happens. Some older babies may be uncomfortable and wake while teething. If you have any concerns about your baby's health, growth, or development, you should talk to your baby's doctor.


2. During the day, give your baby as much opportunity as possible to practice new physical skills, like crawling, pulling up, and climbing over things. The drive to practice these skills can cause older babies to wake. Make sure that the day time naps aren't stretching out so that you can get more done. It is easy to let that happen but you'll be up more at night that way.


3. Keep up a regular bedtime routine. Follow the same pattern of activities each night, ending with your drowsy (or sleeping) little one in the place where you would like him to sleep.


4. Trying leaving something small in the place your baby sleeps (like a burp cloth) that you've been handling or wearing (nothing big like a blanket or pillow - those objects aren't safe for babies). Sometimes anxious babies can be calmed by something that smells like mom (or dad) or other familiar objects.


5. Check the room for blinking lights or other changing sights or sounds that might stimulate your baby in the night. Consider a soft steady night light (turned on during the bedtime routine) and some low level white noise to cover any little sounds that might disturb your baby during periods of lighter sleep.


6. Your baby may want to nurse to go back to sleep because he is anxious or having difficulty calming himself. This would be quite normal for older babies because they don't yet have the skills to understand or control their emotions. While nursing may be both familiar and effective in helping him relax, it is not the only way to calm your baby (if you would rather not nurse). You or your husband can use "repetition to soothe" techniques like stroking, rocking, talking softly or singing to your baby. Your husband can establish a new calming routine that he uses at night when needed. Your baby will not like the change at first (so you might want to start the process when you've had a chance to get some rest or don't have to wake up early the next day) but if you gently persevere, your baby will adapt to the new routine.

Next time: JenB Returns!

Baby Behavior Mysteries: A 9-Month-Old Who Resists his Crib

Recently, we asked readers to share their "baby behavior mysteries" with us. In response, some of you posted questions on the blog and others asked questions at conferences and trainings. Over the next few weeks, we'll be sharing some "solutions" to these mysteries. We won't always be able to make suggestions that might change the babies' mysterious behaviors but we'll do our best to explain why the babies behave the way they do. In today's post, we'll share another one of those sleep-related mysteries that so many parents seem to share.

"My 9-month-old often refuses to let my husband put him back in his crib at night. I have to go in and nurse him every time he's up in order for him to go back to bed and sometimes even then he doesn't want to go back in his crib!"

Big Changes Bring Big Challenges

During the second half of baby's first year, physical, social, and emotional changes continue to accelerate. Your tiny, helpless, mysterious, unpredictable newborn is long gone. Your little one is now active, everywhere, experimenting, emotional, and exhausting! For several months, your baby has been sleeping for longer stretches and you might have had a moment or two where you felt, well...rested. Then sometime around 9 months, you are faced with two common challenges that leave you confused. First, your baby seems very clingy, not wanting to be separated from you even for a few moments and second, he starts to wake a little more often and is stubborn about going back to sleep. Both of these changes can be frustrating for parents but if it is all reassuring to you, these changes are also a normal part of babies' development.

The Explanation

As babies become more able to move away from their parents by crawling, pulling up, rolling, and taking steps, their minds and instincts tell them NOT to stray too far. They might even become anxious if you aren't within sight. "Separation anxiety" is used to describe babies' distress when they realize that mom and dad are not close-by. As your baby gets older, his emotions will seem more intense and you'll find he is less likely to be swayed or quieted by distractions. Complicating things further, babies tend to wake more often between 9 and 12 months for several reasons including changes in routine and the drive to practice new physical skills. So, from your baby's perspective, his desire to be in your arms makes a lot of sense. While playing with your husband may be wonderful and fun during the day, your baby knows that all his anxieties melt away while he's nursing. Therefore, you are the one he wants when darkness and separation become frightening.

So, mystery solved, right?

Except...that you probably want to know what you might do to get a little more rest. That's a lot tougher. We'll share some ideas next time.

Next time: Ideas to Help with a Waking 9-Month-Old

The Science of Infant Sleep Part IV: Falling Asleep versus Staying Asleep

As we wrap up this multi-part series on infant sleep, we return to some of the original questions that led us to focus on this all important area. Several of you asked us about the popular recommendation to make sure that your baby is still partially awake when you put him in his crib. Others wanted to know why babies sleep through the night once or for several weeks and then start waking again. In this post, we'll revisit the interrelationships that we talked about in the last post, but this time, we'll discuss specifically how they may affect your baby's abilities to fall asleep and then stay asleep.

Baby Sleep is Complicated

I'm a big baseball fan (now stay with me, there is a point). One of the things I really love about baseball is that with every new batter, new pitcher, and new situation, the game changes. Baby sleep is a lot like that. Babies' sleep location, their own physical and developmental characteristics, and their parents' behaviors, all interact to influence infants' sleep. And, the game keeps changing as babies grow, as parents change, and when babies sleep in different places. I wish I could give you the answer to get babies to sleep quickly and for long stretches but I continue to believe that there is no single intervention that will help all babies, or even the same baby over time, in all circumstances. Now, I don't mean to imply that there is nothing parents can do. Instead, parents should think of themselves more like the baseball batter adjusting to the pitches that are thrown to them. Some adjustments in parents' actions and in babies' environments will help babies fall asleep, others might help babies stay asleep.

Falling Asleep

Believe it or not, there is a technical term for the time it takes to fall asleep, it's called "sleep-onset latency." Most newborns fall asleep while feeding (but they wake and feed frequently!) so falling asleep becomes more of a problem for older infants, especially those who hate being drowsy. Caffeine exposure and over stimulation can be important factors that might hinder babies' ability to fall asleep. Babies who are sick or uncomfortable (as with teething) will also have problems falling asleep. Dealing with these issues (with help as needed from the doctor) can be a big help to tired parents. But, there are other babies who don't want to fall asleep even when they are not sick or overstimulated. The research we found indicates that consistent bedtime routines (lasting from 20 to 40 minutes) can help babies to wind down. Some routines include a bath, a massage, some rocking, and a story or a song. The key is for parents to be consistent with a series of pleasant and soothing activities night after night. One large study found that a routine helped babies fall asleep faster and stay asleep longer with or without putting the babies down slightly awake.

Staying Asleep

Let's get back to the "put your baby down while awake" recommendation. This suggestion is used primarily as a way to prevent babies from calling out for their caregivers if they wake at night. The idea is that babies who always fall asleep in their parents' arms won't be able to fall asleep any other way. We found several "observational" studies that found that babies who were put down awake were more likely to stay asleep. In observational studies, researchers look at things the way they are and they don't try to change anything as they do in "intervention" studies. Because the same babies who accept being put down awake may sleep longer naturally than those who fight sleep, the relationship between the slightly awake baby and longer sleep may be related more to the baby's characteristics rather than the action of putting the baby down awake. So, we need intervention studies to see if the action results in longer sleep for all babies. This is where it gets tricky. There are plenty of intervention studies that include putting babies down while they are awake but none that includes only this one action (for infants). Most of the interventions include 1) education for parents about infant sleep, 2) standardized bedtime routines, 3) putting baby down at the end of the routine awake or not, and 4) changing parents' response if the baby protests going to sleep. Some of the interventions included instructions for parents to wait to respond (letting the baby cry). In other studies, parents were told to respond by touching the baby (like putting a hand on the baby's back) but not picking the baby up. Some interventions also included white noise, music, and other changes to the sleep environment.

Ok, that's a lot to take in. What does this all mean to you, a tired parent? We'd like to end this series with a few key messages.

• Newborns need to wake for many reasons. Get some help for this tough time.
• A single intervention is not likely to increase sleep for all babies or permanently for any baby.
• When trying to help your baby go to sleep faster and sleep longer, you need to consider his health, age, size and developmental characteristics, your own actions and beliefs, and characteristics of his sleep environment. How a baby sleeps is not an indicator of parenting skill.
• There are a lot of options for parents of older babies to get more sleep. Understanding more about how babies sleep, why they wake, and how "the game changes" over time can help you make informed decisions about what steps will work best for you.

Next time: Back to your questions!

Why We Don't Like "Sleep Training" for Babies: Part II

With this post, we wrap up our 2-part series on the reasons why we don't like "sleep training" systems that come with promises to parents that their use will result in babies' permanently sleeping through the night.

I am going to start with the bad news first. There is no one "system," product, elixir, or gizmo that will make babies sleep magically through the night. Babies will sleep between 12 and 16 hours per day and some will sleep for significant portions of the night even as young as 4 months of age. Many others do not. Now, we don't want you to think that we are suggesting that it is good or healthy for babies to wake up constantly. Healthy babies will slowly but steadily stretch out the time they spend sleeping. All babies are different but here are some guidelines of what parents might reasonably expect:

• Newborns (birth to 6 weeks) wake frequently and erratically. Parents of newborns must be realistic, prepared, and ready to ask for help!
  
• By 2 months, most babies are sleeping longer stretches, but waking 2-3 times during the night.
  
• By 4 months, many babies start to sleep more like their parents, falling asleep into a deeper sleep and sleeping for 4-5 hours at once. Unfortunately, teething and changing routines can increase waking intermittently around this time.
  
• By 6 months, some babies sleep for 6 hours while others are still waking more frequently, though not every night. There are so many changes typically occurring at 6 months, new skills, new activities, new travels, new teeth...older babies sleep well for a few nights, then wake again. It is no wonder that "sleep training" is so popular among parents of babies around this age.
• About 80% of babies sleep through most nights by 1 year of age.

Once past the newborn period, waking that consistently exceeds these rough guidelines might indicate that something is interfering with your baby's ability to sleep. The first step is to check with your doctor to make sure that your baby is healthy and growing well. Some common (non-health- or feeding-related) triggers for waking include:

• Lights from TVs or video games flickering on the wall (steady nightlights are usually ok)
  
• Caffeine in the breastfeeding mother's diet
  
• Changes in daily routine or no consistent routine
  
• Baby is overstimulated or overtired
  
• Too much sleep during the day
  
• The need to practice new motor skills
  
• Noise, but only if it is sudden and quite loud (babies quickly get used to familiar noises)

So what can be done to help older babies sleep longer if sleep training isn't likely to work?

• Establish routines! Repeated activities and experiences are calming to babies and help them establish body rhythms that are closer to those of their parents. Bedtime routines allow babies time to shift naturally from a drowsy state into sleep. Babies will differ in how much time they need to become ready for sleep; many take at least 20 minutes. Believe it or not, you'll miss the bedtime routines when your children outgrow them.
  
• Reduce or eliminate caffeine for breastfeeding mothers (don't worry, you'll get to have that morning mocha again). Babies' bodies take a lot longer to get rid of caffeine than we do. Remember there is caffeine in tea, sodas, energy drinks, and other products. Read labels.
  
• Make sure that baby isn't overstimulated close to bed time (this is easy to do if parents typically get home late from work). Watch for indications that your baby is drowsy and start your bedtime routine right away. If you wait too long, you might end with a screaming, overtired baby who will be less likely to sleep than a baby put to bed earlier.
  
• Make sure that baby spends plenty of time awake during the day. Give babies plenty of chance to be active, moving, and practicing their new skills during the day.
• Include a special bedtime toy in your bedtime ritual, something that is safe to leave with baby as he drifts into sleep.
  
• Don't end your routine with baby being completely asleep. When babies are put down when they are very drowsy but before they are asleep, they may be better at putting themselves back to sleep if they wake in the night. This doesn't work with babies who hate feeling drowsy and resist sleeping at all costs! I had one of those! The trick is that the baby must be very drowsy or very accustomed to this as an end to the night time routine.
  
• Recognize that most babies make noise when drifting to sleep or they are dreaming, don't assume that intermittent noises mean your baby needs you immediately. Give your older baby a few moments to fall asleep or get back to sleep on his own.

We understand what it is like to be sleep deprived working moms. We also realize that families need to make their own decisions about how they deal with their infants' sleep patterns. But, unrealistic expectations about infant sleep may lead to feelings of frustration, resentment, and insecurity for parents who already are under enough stress. Infant sleep duration is not an indicator of parenting skills. Gaining understanding of how babies sleep patterns evolve, using cues, and developing consistent day- and nighttime routines can result in less stress, more sleep, and much happier babies and parents.

Next time: Answers to more reader questions.

Starting Solid Foods: It's Worth the Wait

I can remember being very excited to start solids foods with my daughter (what dietitian turned first time mom wouldn’t be, right?). I saw starting solids as an important milestone to be achieved. And though I knew that starting solid foods would not help my baby sleep through the night (yes, I’ve read the research!), I secretly hoped it might help her sleep just a little bit longer. I can remember family members saying “Oh! She’s eating solids now. She must be sleeping more at night!” Then, they would look at me strangely when I would say “Nope. It had no effect on her sleep. In fact, she may be waking more frequently now.” They would counter with: “Wow. She’s a stubborn one!” True. She was (and is) one stubborn girl, but babies sleep through the night when they are ready to, and starting solids or giving a nice hearty bowl of oatmeal before bedtime won’t change that.

I’m sure I was not the first parent (or the last) to be confused by all of the information out there about starting solid foods. So, the following information is based on the American Academy of Pediatrics recommendations, my experience as a dietitian working with mothers and infants in a clinic setting, and my experience raising (and feeding) my own little girl.

The Recommendations
In the past, parents have been told to start solid foods when their babies are around 4-months old. Then, in 2004, the American Academy of Pediatrics provided updated recommendations stating that “infants may be physically ready to accept solid foods sometime between 4 and 6 months.” And just to make it more confusing, the Breastfeeding Section of the American Academy of Pediatrics* published their own recommendation stating that “Complementary foods rich in iron should be introduced gradually beginning around 6 months of age.” But, results from a 2008 study** showed that nearly half of all infants are still being fed solid foods before 4 months, and many doctors are still recommending starting solids around 4 months old. No wonder parents are confused!

Why wait so long?
While an infant’s GI (gastrointestinal) tract may be capable of handling solid foods by 3-4 months of age, oral, gross, and fine motor skills required for eating solids generally don’t emerge until around 4-6 months of age. Yes, that is a wide age range, but the new guidelines focus more on developmental readiness than on age. One baby may be ready at 4 months, while another isn’t ready until 6. When I tried to feed my daughter baby cereal at about 5 ½ months, she immediately turned her head away. I tried again at her next mealtime and she spit the cereal all over me. I took that as a sign that she wasn’t quite ready.

Ready or not?
So, how do you know for sure when a baby is developmentally ready to eat solid foods? Your baby needs to be able to do ALL of the following things to be ready to eat solid foods: sit up with support, hold her head steady, put her fingers or toys in her mouth, show she wants food by opening her mouth, close her lips over her spoon, show she doesn't want food by turning her head away and keep food in her mouth and swallow it.

What to feed first
The important thing is to start with an iron-rich food. Examples are iron-fortified infant cereal or baby food meats. Many parents start with cereal. You do want to start with single-ingredient foods, and feed only one food at a time to identify any foods that the baby may be allergic to. After starting a high-iron food, there is no specific order for new foods as long as there is a gradual progression of textures as tolerated. The progression of textures is smooth, mashed, chopped, and then tiny pieces. Just be sure that one texture can be chewed and swallowed before moving onto the next one.

How much should I feed?
Watch your baby’s cues. Babies will let you know when they have had enough. My daughter was very dramatic about this. When she was full, she would pick up her bowl of food and throw it across the room. Other, less messy, fullness cues include slowing the pace or stopping eating, spitting out or refusing the food or spoon, batting the spoon away, or closing mouth as spoon approaches. Maybe I should have paid closer attention to those early cues!

A final word about solid foods
If your baby doesn’t eat solid foods when you first offer them, don’t panic! At first, babies must learn to eat solid foods. Respect your baby’s fullness or disengagement cues, and try offering the food at a later feeding or on another day or week. Never force your baby to eat; that can create feeding problems later in life. As far as sleeping through the night is concerned, adding a little cereal before a baby is ready for it can do more harm than good and it won’t help a baby sleep longer. Starting solid foods early has been linked to increased risk for developing allergies and diabetes. As always, talk to your baby’s doctor about when it is best for you to start solid foods. But be sure to watch for those early disengagement cues, or you might get hit by a flying bowl!

Next time: What to Expect from Follow-up Appointments with A Preterm Baby

*http://www.pediatrics.org/cgi/content/full/122/Supplement_2/S25
**http://pediatrics.aappublications.org/cgi/reprint/115/2/496