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Sleep Training Truths: What Science Can (And Can't) Tell Us About Crying It Out

Michaeleen Doucleff

Credit: Scott Bakal for NPR

Welcome to parenthood! For many of us, parenthood is like being air-dropped into a foreign land, where protohumans rule and communication is performed through cryptic screams and colorful fluids. And to top it off, in this new world, sleep is like gold: precious and rare. (Oh, so precious.)

Throughout human history, children were typically raised in large, extended families filled with aunts, uncles, grannies, grandpas and siblings. Adding another baby to the mix didn't really make a big dent.

Nowadays, though, many moms and dads are going about it alone. As a result, taking care of a newborn can be relentless. There are too few arms for rocking, too few chests for sleeping and too few hours in the day to stream The Great British Bake Off . At some point, many parents need the baby to sleep — alone and quietly — for a few hours.

And so, out of self-preservation, many of us turn to the common, albeit controversial, practice of sleep training, in hopes of coaxing the baby to sleep by herself. Some parents swear by it. They say it's the only way they and their babies got any sleep. Others parents say letting a baby cry is harmful.

What does the science say? Here we try to separate fiction from fact and offer a few reassuring tips for wary parents. Let's start with the basics.

Myth: Sleep training is synonymous with the "cry-it-out" method.

Fact: Researchers today are investigating a wide range of gentler sleep training approaches that can help.

The mommy blogs and parenting books often mix up sleep training with "cry it out," says Jodi Mindell , a psychologist at Children's Hospital of Philadelphia who has helped thousands of babies and parents get more sleep over the past 20 years. In fact, most of the time, it's not that.

"I think unfortunately sleep training has gotten a really bad rap because it's been equated with this moniker called 'cry it out,' " Mindell says.

Indeed, the cry-it-out approach does sound cruel to many parents. "You put your baby into their crib or their room, you close the door and you don't come back till the next day," Mindell says. "But that's not the reality of what we recommend or what parents typically do."

And it's not what scientists have been studying over the past 20 years. Cry-it-out is an old way of thinking, says Mindell, author of one of the most frequently cited studies on sleep training (and the popular book Sleeping Through The Night ).

In today's scientific literature, the term "sleep training" is an umbrella term that refers to a spectrum of approaches to help babies learn to fall asleep by themselves. It includes much gentler methods than cry-it-out or the so-called Ferber method . For example, some sleep training starts off by having the parent sleep next to the baby's crib (a method called camping out) or simply involves educating parents about baby sleep.

"All these methods are lumped together in the scientific literature as 'sleep training,' " Mindell says.

In several studies, parents are taught a very gentle approach to sleep training. They are told to place the baby in the crib and then soothe him — by patting or rubbing his back — until he stops crying. The parent then leaves the room. If the baby begins crying, the parent is supposed to check in after waiting some amount of time. In one study , these types of gentle interventions reduced the percentage of parents reporting sleep problems five months later by about 30%.

Myth: There's a "right" amount of time to let your baby cry when you're trying to sleep train.

Fact: There's not a strict formula that works for every parent (or baby).

There isn't a magic number of minutes that works best for checking on a baby after you've put her down, Mindell says. It really depends on what parents feel comfortable with.

"Doesn't matter if you come back and check on the baby every 30 seconds or whether you come back every five minutes," she says. "If it's your first child you're going in every 20 seconds." But by the third, she jokes, 10 minutes of crying may not seem like a lot.

There is no scientific data showing that checking every three minutes or every 10 minutes is going to work faster or better than checking more often. There are about a dozen or so high-quality studies on sleep training. Each study tests a slightly different approach. And none really compares different methods. In many studies, multiple methods are combined. For example, parents are taught both how to sleep train and how to set up a good bedtime routine. So it's impossible to say one approach works better than the other, especially for every baby, Mindell says.

Instead of looking for a strict formula — such as checking every five minutes — parents should focus on finding what Mindell calls "the magic moment" — that is, the moment when the child can fall asleep independently without the parent in the room. For some children, more soothing or more check-ins may help bring forth the magic, and for other babies, less soothing, fewer check-ins may work better.

With my daughter, I finally figured out that one type of crying meant she needed some TLC, but another meant she wanted to be left alone.

Even having a good bedtime routine can make a difference. "I think education is key," Mindell says. "One study I just reviewed found that when new parents learn about how babies sleep, their newborns are more likely to be better sleepers at 3 and 6 months."

"So you just have figure out what works best for you, your family and the baby's temperament," she says.

Myth: It's not real sleep training if you don't hear tons of crying.

Fact: Gentler approaches work, too. And sometimes nothing works.

You don't have to hear tons of crying if you don't want, Mindell says.

The scientific literature suggests all the gentler approaches — such as camping out and parental education — can help most babies and parents get more sleep, at least for a few months. In 2006, Mindell reviewed 52 studies on various sleep training methods. And in 49 of the studies, sleep training decreased resistance to sleep at bedtime and night wakings, as reported by the parents.

There's a popular belief that "cry it out" is the fastest way to teach babies to sleep independently. But there's no evidence that's true, Mindell says.

"Parents are looking for like what's the most effective method," Mindell says. "But what that is depends on the parents and the baby. It's a personalized formula. There's no question about it."

And if nothing seems to work, don't push too hard. For about 20% of babies, sleep training just doesn't work, Mindell says.

"Your child may not be ready for sleep training, for whatever reason," she says. "Maybe they're too young, or they're going through separation anxiety, or there may be an underlying medical issue, such as reflux."

Myth: Once I sleep train my baby, I can expect her to sleep through the night, every night.

Fact: Most sleep training techniques help some parents, for some time, but they don't always stick.

Don't expect a miracle from any sleep training method, especially when it comes to long-term results.

None of the sleep training studies are large enough — or quantitative enough — to tell parents how much better a baby will sleep or how much less often that baby will wake up after trying a method, or how long the changes will last.

"I think that idea is a made-up fantasy," Mindell says. "It would be great if we could say exactly how much improvement you're going to see in your child, but any improvement is good. "

Even the old studies on cry-it-out warned readers that breakthrough crying sometimes occurred at night and that retraining was likely needed after a few months.

The vast majority of sleep training studies don't actually measure how much a baby sleeps or wakes up. But instead, they rely on parent reports to measure sleep improvements, which can be biased. For example, one of the high-quality studies found that a gentle sleep training method reduced the probability of parents reporting sleep problems by about 30% in their 1-year-old. But by the time those kids were 2 years old, the effect disappeared .

Another recent study found two kinds of sleep training helped babies sleep better — for a few months. It tried to compare two sleep training approaches: one where the parent gradually allows the baby to cry for longer periods of time and one where the parent shifts the baby's bedtime to a later time (the time he naturally falls asleep), and then the parent slowly moves the time up to the desired bedtime. The data suggest that both methods reduced the time it takes for a baby to fall asleep at night and the number of times the baby wakes up at night.

But the study was quite small, just 43 infants. And the size of the effects varied greatly among the babies. So it's hard to say how much improvement is expected. After both methods, babies were still waking up, on average, one to two times a night, three months later.

Bottom line, don't expect a miracle, especially when it comes to long-term results. Even if the training has worked for your baby, the effect will likely wear off, you might be back to square one, and some parents choose to redo the training.

Myth: Sleep training (or NOT sleep training) my children could harm them in the long term.

Fact: There's no data to show either choice hurts your child in the long-run.

Some parents worry sleep training could be harmful long-term. Or that not doing it could set up their kids for problems later on.

The science doesn't support either of these fears, says Dr. Harriet Hiscock , a pediatrician at the Royal Children's Hospital in Melbourne, Australia, who has authored some of the best studies on the topic.

In particular, Hiscock led one of the few long-term studies on the topic. It's a randomized controlled trial — the gold standard in medical science — with more than 200 families. Blogs and parenting books often cite the study as "proof" that the cry-it-out method doesn't harm children. But if you look closely, you quickly see that the study doesn't actually test "cry it out." Instead, it tests two other gentler methods, including the camping out method.

"It's not shut the door on the child and leave," Hiscock says.

In the study , families were either taught a gentle sleep training method or given regular pediatric care. Then Hiscock and colleagues checked up on the families five years later to see if the sleep training had any detrimental effects on the children's emotional health or their relationship with their parents. The researchers also measured the children's stress levels and accessed their sleep habits.

In the end, Hiscock and her colleagues couldn't find any long-term difference between the children who had been sleep trained as babies and those who hadn't. "We concluded that there were no harmful effects on children's behavior, sleep, or the parent-child relationship," Hiscock says.

In other words, the gentle sleep training didn't make a lick of difference — bad or good — by the time kids reached about age 6. For this reason, Hiscock says parents shouldn't feel pressure to sleep train, or not to sleep train a baby. "I just think it's really important to not make parents feel guilty about their choice [on sleep training]," Hiscock says. "We need to show them scientific evidence, and then let them make up their own minds."

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Infant sleep and its relation with cognition and growth: a narrative review

Elaine kh tham, nora schneider, birit fp broekman.

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Correspondence: Birit FP Broekman, Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research (A*STAR), Brenner Centre for Molecular Medicine, 30 Medical Drive, Singapore 117609, Singapore, Tel +65 9009 5444, Fax +65 6776 6840, Email [email protected]

Collection date 2017.

The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution – Non Commercial (unported, v3.0) License ( http://creativecommons.org/licenses/by-nc/3.0/ ). By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed.

Infant sleep development is a highly dynamic process occurring in parallel to and in interaction with cognitive and physical growth. This narrative review aims to summarize and discuss recent literature and provide an overview of the relation between infant sleep and cognitive development as well as physical growth.

We conducted online literature search using MEDLINE, Embase, and Cochrane Library databases. We considered original research on humans published in the English language from January 2005 to December 2015. Search terms included “sleep” AND “infant” AND “cognition” OR “memory” OR “executive functioning”, OR “growth” OR “obesity” OR “growth hormone” OR “stunting”, and combinations thereof.

Ten studies on infant sleep and cognition were included in this review. Overall, findings indicated a positive association between sleep, memory, language, executive function, and overall cognitive development in typically developing infants and young children. An additional 20 studies support the positive role of infant sleep in physical growth, with the current literature focusing largely on weight gain and obesity rather than healthy growth. Existing evidence in both the domains is mainly based on cross-sectional designs, on association studies, and on parental reports. In contrast, there were limited studies on longitudinal sleep trajectories and intervention effects, or studies have not used more objective sleep measures such as actigraphy and polysomnography.

The reviewed studies support a critical and positive role of infant sleep in cognition and physical growth. Future studies should consider key environmental and parental confounders, include a combination of more objective (actigraphy) and subjective measures (sleep diaries and questionnaires), and move towards longitudinal trajectory designs of infant sleep and development.

Keywords: infant sleep, cognition, growth

Introduction

Sleep develops rapidly during the first few years of life and is a highly dynamic process. At birth, infants lack an established circadian rhythm and hence sleep across multiple intervals throughout the day and night in short bouts, which may also be due to infants’ feeding needs. 1 At about 10–12 weeks of age, the first signs of a circadian rhythm begin to develop, marked by an increased ease of sleeping through the night. 2 The change in total sleep duration over 24 hours continues and decreases from 16 to 17 hours in newborns, to 14–15 hours at 16 weeks of age, and 13–14 hours by 6 months of age. 3 , 4 While the need for day sleep decreases, 5 night sleep duration increases through the first year of life, 5 – 7 resulting in a shift towards more nocturnal patterns of sleep.

Infant sleep studies show that about 20%–30% of all infants experience night awakenings throughout their first 2 years of life. 8 , 9 Yet, with children’s development, the number of awakenings per night reduces, and the ability to sleep through the night increases witĥ50%–75% of infants sleeping through the night at 12 weeks of age 10 and at least 90% at 6 months of age. 11 Despite the general trend of decrease, night awakenings show the highest levels of variability across all sleep measures, 4 which makes it an interesting research target for sleep quality in young infants.

Concerns that children are not getting enough sleep have been around for over 100 years, with recommendations of ideal sleep duration for children being provided as early as 1897. 12 The National Sleep Foundation (NSF) recommends a daily sleep duration of 14–17 hours/day from birth to 3 months, 12–15 hours/day from 4 to 11 months, 11–14 hours/day for infants aged 1–2 years, and 10–13 hours/day for preschoolers aged 3–5 years. In all cases except for newborns to 3 months, the latest NSF recommendations increased by at least 1 hour from the preceding (NSF) recommendations due to reported changes in sleep durations over the last years (from a systematic literature search) as reviewed by an expert panel. 13 However, many infants and young children sleep less than the above-recommended amount. 12 Short sleep duration is particularly prevalent in predominantly Asian countries. A study conducted on caregivers of 29287 children between the ages of 0 and 36 months from 17 countries reports that total sleep duration in children from predominantly Asian counties is significantly lower than children from predominantly Caucasian countries. 14 Moreover, regardless of age group, children from predominantly Asian countries consistently sleep less or at the lower extreme of the NSF recommendation.

Sleep is a highly dynamic developmental process, particularly in the first 2 years of life, with a high inter- and intraindividual variability. While many studies have focused on children, the link between variations in sleep and developmental outcomes in healthy infants remains less explored. The objective of this narrative review is therefore to summarize and evaluate available literature on the relation between infant sleep during the first 2 years of life and cognitive and physical growth in healthy typically developing infants and young children.

We searched MEDLINE, Embase, and Cochrane Library databases for articles in English and published between 2005 and December 2015. Search terms included “sleep” AND “infant”, in combination with “cognition” OR “memory” OR “executive functioning” OR “growth” OR “obesity” OR “growth hormone” OR “stunting”. Search terms had to be present in either the title or the abstract of the article. In addition, we limited results to original research articles investigating infant sleep during the first 2 years of life in relation to cognitive development and physical growth outcomes both during the first 2 years of life or later, human studies, and studies on term-born, cognitively healthy infants. Studies on sleep disorders, including sleep-disordered breathing symptoms, were excluded from this review, as well as studies in psychiatric populations or preterm infants.

Our literature search resulted in the following hits:

Sleep and infant and cognition, and/or memory, and/or executive functioning: 85 MEDLINE hits, 89 Embase hits, and eight Cochrane Library hits. After examining all the extracted titles and abstracts, 31 overlapping articles were removed, four articles were excluded as they were review papers that did not have a focus on sleep and cognition in healthy typically developing infants, and 98 were excluded as sleep was not the main variable of interest or that sleep was not measured during infancy amongst healthy term-born infants. After the exclusion, ten publications were considered relevant for the scope of the review.

Sleep and infant and growth and/or obesity and/or growth hormone and/or stunting: 29 MEDLINE hits, four Cochrane Library hits, and 47 Embase hits. Of the 80 screened publications, 29 were considered for inclusion having removed overlapping publications. After screening titles and abstracts and reading the full-length papers, 20 publications were considered relevant for infant sleep and growth, and hence included in this review.

Infant sleep and cognition

Sleep is a period that is characterized by marked change in brain activity, 15 in addition to being a resting period of reduced sensory activity and responsiveness to external stimuli. 16 As such, sleep has been related to subsequent cognitive and developmental benefits. 17 Multiple studies have found relationships between sleep duration and cognitive benefits in school-aged children. 18 – 21 Unlike studies on older children, there have been fewer studies regarding the effects of infant sleep on cognitive outcomes. Out of the ten studies reviewed in this paper, seven were cross-sectional studies, and three were longitudinal studies. Table 1 presents a summary of the reviewed articles.

Summary of reviewed studies for sleep and cognitive development

Abbreviations: WPPSI, Wechsler Preschool and Primary Scale of Intelligence; BMI, body mass index.

Cross-sectional studies

The majority of the reviewed articles for sleep and cognition consist of cross-sectional studies. Within the cross-sectional studies, four studies focused on the effect of post-learning sleep on memory consolidation, one study examined relations between sleep (1 week) prior to learning and subsequent memory, and two studies investigated overall associations between sleep and general cognitive development.

Similar to findings in adults, 22 , 23 researchers have found evidence that infant sleep also plays an important role in memory consolidation, a process whereby a initially weak memory representation becomes stable and more resistant to forgetting. 22 , 24 Seehagen et al found that 6- and 12-month-old infants who napped for at least 30 minutes after learning a set of object–action pairings from a puppet toy recalled significantly more target actions while tested after 4-hour delay and 24-hour delay compared to infants in the baseline condition who were not trained on the object–action pairings and to infants in the no-nap group who spent an equivalent time awake after learning (at the 24-hour delay test). 25 Even though the researchers found an overall benefit of sleep towards object–action memory especially compared to infants in the baseline condition and at the 24-hour delay test, it should be noted that there were no differences in memory performance between the nap group and no-nap group at the 4-hour delay test.

Apart from object–action memory, studies have also shown that infant sleep, in particular daytime naps, is beneficial towards language learning. Gómez et al found that after learning an artificial language, 15-month-old infants who napped for at least 30 minutes were able to abstract grammatical relations amongst the learnt words at a subsequent test session that occurred 4 hours after learning, where they looked longer at trials where stimuli were consistent with the learnt artificial language as compared to inconsistent trials. 26 In contrast, infants who did not nap (but spent an equivalent time awake) did not look significantly longer at consistent compared to inconsistent trials during testing, and hence were not able to learn the abstracted relations between the artificial language. 26 In addition, a further experiment by the above researchers on a similar group of 15-month-old infants showed that the nap-dependent benefits towards language learning (where infants learnt abstract grammatical relations) persisted even after 24 hours. 27 A recent study by a separate group of researchers also highlighted nap-dependent benefits towards language in terms of vocabulary learning. 28 In the study, Horváth et al found that 16-month-old infants who napped after learning sets of new object–word associations spent more time looking at the correct associative pairing at the 2-hour delayed test session, whereas infants who remained awake did not display any differences in looking between the learning and delayed test sessions.

Overall, the above studies on object–action memory and language learning all support the claim that sleep benefits memory consolidation. However, it is interesting that there were no differences between the nap and no-nap group at the 4-hour delay test in Seehagen et al’s object–action memory study, whereas differences between infants who napped and those who spent an equivalent time awake emerged after a similar 4-hour delay in Gómez et al’s study on language learning. In Horváth et al’s vocabulary-learning study, the nap-dependent effects were present just after at a 2-hour delayed test session. One possible reason for the different findings could be that the infants in Seehagen et al’s study were younger (6- and 12-month olds) than the 15- and 16-month olds in Gómez et al’s and Horváth et al’s studies; sleep changes and matures rapidly during infancy, 29 and hence the 3- to 10-month age difference between the infants may have contributed to the different sleep-associated effects between the studies. Another reason for the difference in findings may be due to the nature of the experimental task and test stimuli. Studies in adults demonstrate that sleep shows a preferential benefit towards memories that are deemed to be more relevant for the future. 30 , 31 It is plausible that the object–action associations in Seehagen et al’s study are “less relevant” to 6- and 12-month-old infants, whereas the language stimuli in Gómez et al’s and Horváth et al’s studies may be more relevant and salient to the 15- and 16-month-old infants who are also undergoing a period of rapid vocabulary development (“vocabulary spurt”). 32

In addition to post-learning sleep, a study by Lukowski and Milojevich indicates that normative variation in everyday habitual infant sleep prior to learning may also affect memory of the newly learnt information. 33 First, the researchers collected parental reports of twenty-five 10-month-old infants’ sleep habits for the week prior to the encoding session. Next, during the encoding session, the infants were visually presented with six two-step object–action event sequences with narration during an encoding session. Recall memory and memory generalization (ability to generalize responses to new stimuli that were similar to those presented at encoding) were tested after a 2-hour delay. Infants with a greater number of night awakenings performed poorer (displayed fewer target actions) in the memory generalization task, and infants with longer daytime nap durations performed better in the same task. There was a positive relation between duration of daytime naps and memory recall immediately after encoding, and a negative correlation between higher percentages of night sleep duration (out of total sleep duration) and immediate recall. In contrast, there was no relation between habitual sleep duration and delayed memory recall of the event sequences. The lack of significant associations between sleep duration and memory recall of the object–action event sequences at the delayed testing session is particularly interesting in comparison to the positive nap-dependent effects in the reviewed memory consolidation studies where infants who napped displayed better memory and learning when they were tested after a delay.

Although the cross-sectional studies amongst typically developing infants mainly focused on memory consolidation and learning, two of the reviewed studies examined the relation between infant sleep and general cognitive development. In the first study, researchers found that greater movements or activity during sleep and greater number of awakenings after sleep onset measured via sleep actigraphy recordings were negatively correlated with scores on the Bayley Scales of Infant and Toddler Development second edition (BSID-II) Mental Development Index (MDI) amongst 10-month-old infants. 34 In contrast, greater sleep efficiency (i.e. spending a larger percentage of time asleep between sleep onset and wakefulness) was positively correlated with BSID-II MDI scores in the same group of infants. 34 In the second study, researchers found that 11- to 13-month-old infants who had greater sleep efficiency measured via sleep actigraphy data also displayed better overall cognitive problem-solving skills as measured by the Ages and Stages Questionnaire. 35 Besides sleep efficiency, longer proportions of sleep at night were also associated with better cognitive problem-solving skills. 35 It should be noted that both of these studies also explored parental sleep reports in addition to sleep actigraphy data; however, unlike the sleep actigraphy data, there were no significant associations between parental sleep reports and any of the cognitive measures.

Despite the fact that all the reviewed cross-sectional studies showed sleep-associated benefits, there were no consistent findings amongst the studies regarding the component of sleep (i.e. sleep duration, sleep efficiency, night awakenings, etc.) that benefitted cognition. However, it may also not be feasible to directly compare the studies due to differences in study design as the effects of sleep in the memory consolidation studies were explored in a between-participant design involving sleep within a nap period, whereas Lukowski and Milojevich’s study and the two studies on general cognitive development explored within-infant normative variations in sleep habits.

Longitudinal studies

In addition to the above-mentioned cross-sectional studies, three studies investigated longitudinal relations between sleep and cognition. Two out of the three studies highlighted that infant sleep was related to subsequent executive functioning during toddlerhood and early childhood. 36 – 38 One of the studies showed that higher percentages of parent-reported night sleep (out of total sleep duration) at 12 and 18 months of age were significantly associated with better executive functioning performance at 26 months of age, especially performance related to impulse-control tasks. 38 The benefits of higher percentages of sleep duration at night seemed to extend beyond toddlerhood. Findings from a second study report that 12-month-old infants with higher proportions of night sleep displayed better executive functioning performance at 4 years, measured by the Matrix Reasoning subscale of Wechsler Preschool and Primary Scale of Intelligence (WPPSI) third edition. 37 In contrast, the study found that there was no relation between 12-month-old sleep duration and concurrent general cognitive functioning (Bayley Scales of Infant Development). 37 In all the above studies, the longitudinal relations between infant sleep and executive functioning were independent of confounders such as family socioeconomic status.

One of the reviewed longitudinal studies explored the relation between infant sleep, psychosocial adversity, and IQ scores (assessed using the WPPSI – Revised). 39 Unlike the studies on infant sleep and executive functioning, the longitudinal relation between infant sleep and IQ scores of WPPSI – Revised seems less direct. This current study reports high amounts of maternal-reported infant sleep difficulties and sleep disturbances at 12 and 18 months to be correlated with lower IQ scores at 5 years of age. 39 However, the above finding was no longer statistically significant after adjusting for psychosocial adversity. In addition, the study did not find any significant relations between IQ scores and sleep actigraphy data that were collected at 5 years of age.

In summary, ten studies have been identified that describe the relation between sleep and cognition in typically developing infants. Cross-sectional studies revealed that, similar to adults, sleep benefits memory and (language) learning in infants, both before and after learning. Although all reviewed memory and language-learning studies showed sleep-associated benefits towards cognition, the sleep parameter (i.e. night sleep duration, daytime napping, night awakenings, etc.) that benefitted cognition remained inconsistent. Longitudinal studies on infant sleep and executive functioning consistently showed that higher percentages of parent-reported infant night sleep were related to better subsequent executive functioning performance. 36 – 38 However, it should be noted that the studies were conducted by a single research group using the same participant pool. Although this may not affect the validity of the findings, replication studies in other samples would be useful in interpreting the generalizability of the findings beyond the existing participant pool. 25 – 28 , 33 Although majority of the cross-sectional studies recorded sleep via actigraphy data, the sleep data used in the longitudinal studies were primarily obtained from parental reports. Future longitudinal studies may also consider collecting sleep data via actigraphy; especially, some cross-sectional studies have reported sleep-associated findings with actigraphy data but not parental reports. 34 , 35

Infant sleep and growth

Sleep is controlled by chronobiological mechanisms, and the most rapid development in sleep organization occurs during the first 6 months of life, a period that is also marked by rapid physical growth. Yet, the relation between sleep and growth with a focus on infancy, early childhood, and healthy development has not been systematically addressed in the literature. However, some plausible relationships between sleep and growth have been explored, mainly in epidemiological studies: i) sleep and weight gain/obesity, ii) growth retardation/stunting and sleep, and iii) sleep and growth hormone. Table 2 provides a summary of the reviewed studies.

Summary of reviewed studies for sleep and growth

Abbreviation: BMI, body mass index.

Weight gain and obesity measures

Compared to adolescent and adult studies, only a few studies have examined the impact of sleep on physical growth parameters in infants specifically. However, the relation to obesity appears one of the most investigated concepts with regard to sleep. A study for example found that infant sleep of <12 hours/day in the first 2 years of life was associated with a higher body mass index (BMI), skinfold thickness, and an increased risk of being overweight at 3 years. 40 Secondary analyses of longitudinal changes in sleep duration over the first 3 years of life revealed an increase in mean weight-for-length z -score by 0.02 for each hour/day decrease. Analyses based on the same cohort confirmed the inverse relation of sleep duration of <12 hours/day and the probability of overweight at 3 years of age. 41 The cut-off at 12 hours/day seems supported by the GUSTO study in Singapore which reported sleep of <12 hours/day at 3 months of age to be associated with a higher BMI and shorter body length. 42 However, in both studies, sleep data were based on parental report of infant sleep, while no objective sleep measures were applied. A cross-sectional study points in the same direction: a shorter sleep duration as assessed by parent report was linked to an increase in weight-to-length ratio as early as 6 months of life. In girls only, those findings could be substantiated by actigraphy data with a shorter sleep duration being associated with larger body size measures. 43 In contrast, a study of actigraphic sleep in 1-year-old infants 35 and an observation study using a sleep-monitoring device over the first 6 months of life 44 did not find significant correlations with BMI or weight gain. Similarly, researchers did not find any significant association between sleep duration at 24 months as assessed by sleep questionnaire and BMI or risk of overweight at the age of 3 years in the Born in Bradford birth cohort study. 45 Looking at longer term consequences of infant sleep, a follow-up of the above-mentioned prospective cohort highlights as one of the first studies of the impact of chronic sleep curtailment from infancy to mid-childhood on BMI and adiposity measures. 40 Children with less sleep compared to children with more sleep had a higher BMI z -score, skinfold thickness, total and trunk fat mass index, waist circumference, hip circumference, and higher odds of obesity. Curtailed sleep was defined as <12 hours/day from age 6 months to 2 years, <10 hours/day from age 3–4 years, and <9 hours/day from age 5–7 years. 46

One of the mediating factors in the relation of sleep and weight gain or risk of obesity may be energy intake, as suggested by a study of 16-month-old children of the Gemini twin birth cohort. While the association between sleep and weight was not significant at this age, shorter nighttime sleep as measured by a sleep questionnaire was associated with a higher total energy intake, with children sleeping <10 hours consuming around 50 kcal/day more than children sleeping 11–12 hours a night. 47

In addition, most evidence from our review stems from observation and cohort studies, whereas evidence from intervention studies is still scarce. Only two intervention studies were identified in the context of this review and yielded mixed findings. A pilot randomized controlled trial investigating the effect of modification of parental behaviors with regard to feeding, sleeping, and crying on infant weight gain and early obesity risk found that behavioral modification resulted in lower weight-for-length percentiles at 1 year of age for infants who received a combined soothe/sleep and introduction of solid foods intervention (33rd percentile; P = 0.009) compared to those who received the soothe/sleep intervention only (50th percentile), to those who received the introduction of solid foods intervention only (56th percentile), and to the control group (50th percentile). In addition, the soothe/sleep intervention yielded prolonged nocturnal sleep during the first year of life compared to the control group, especially in predominantly breast-fed infants. 48 As the observed effect on weight gain was strongest in the combined intervention, it cannot be attributed to longer sleep duration as such, but those findings suggest that prolonged nocturnal sleep plays a relevant role as part of a multicomponent intervention early in life. This study served as a pilot to the larger, currently ongoing Intervention Nurses Start Infants Growing on Healthy Trajectories (INSIGHT) study. 49 In contrast, a short intervention delivering behavioral sleep strategies from 8 to 10 months postpartum did not show beneficial effects on BMI z -score, percentage of overweight/obesity, and waist circumference at 6 years of life. 50 The two intervention studies differ in several aspects, most notably in intervention duration and intensity (1 year vs 2 months), start of intervention (shortly after birth vs at 8 months), follow-up duration (1 year versus 6 years), and most importantly in modulating sleep as a single factor versus modulating multiple factors to impact weight gain and risk of obesity.

Overall, those results indicate the potential risk of shorter sleep duration early in life for overweight and adiposity later in life. Suggested mechanisms that link shorter sleep or sleep restriction to weight gain, obesity, and insulin resistance include counter-regulatory hormones such as cortisol and growth hormone, 51 altered activity of the autonomous nervous system, 52 and the alteration of appetite-regulating hormones like leptin and ghrelin which increases appetite and hunger. 53 Behaviorally, longitudinal data analyses, for example, from the National Longitudinal Study of Adolescent Health, suggest an association between later bedtime and an increase in BMI. 54

Length and height

A recent study suggests sleep and episodic length growth in 4- to 17-month-old infants to be a temporally coupled process with prolonged sleep preceding length growth by 0–4 days. 55 The authors found an increase of up to 4.5 hours and/or three more naps per day to be predictive of length growth suggesting an underlying biological system. In turn, growth restriction or growth-rate reduction as early as in utero (intrauterine growth restriction, IUGR) alters sleep patterns. 56 , 57 IUGR fetuses have decreased amounts of active sleep and increased amounts of quiet sleep and indeterminate sleep compared to appropriately grown fetuses. The time spent in active sleep could have an especially significant effect on brain maturation. 58 Those alterations in sleep organization early in life may persist into childhood: a study showed, for example, lower sleep efficiency and more awakenings during the sleep period in IUGR children aged 4–7 years. 59 In addition, researchers investigated the relation between stunting, iron deficiency anemia, and maternal reports of sleep in 6- to 18-month-old infants in two studies from Zanzibar and one from Nepal. 60 Stunting was associated with a shorter night sleep duration, higher frequency of night waking, and shorter nap duration.

While related mechanisms are not yet well understood, sleep plays an important role in energy balance. Altered sleep-state organization may be an adaptive response to preserve energy in states of IUGR or stunting. 58

Growth hormone

A bidirectional interaction between hormones and sleep can be assumed. Several hormones are both involved in circadian rhythm and sleep and affected by the quantity and quality of sleep. Those hormones include, for example, melatonin, cortisol, leptin, ghrelin, insulin-like growth factor-1, pro-lactin, and growth hormone. 61 The latter hormone plays a major role in stimulating body growth, and its high levels in plasma of infants suggest an important role in the first months of life. 62 The secretion of growth hormone is influenced by factors such as nutrition, physical activity, and sleep patterns. Increased levels of hormones are secreted during sleep, peaking shortly after sleep onset. 63 In the context of this review, no study has been identified to specifically investigate the link or the impact of growth hormone on sleep in healthy infants and young children. While well-characterized data on growth hormone release in association with healthy sleep pattern maturation during the first months of life are lacking, 64 pediatric patients with growth hormone deficiency have been shown to display a reduced total sleep time with increased wakefulness and subsequently a decrease in sleep efficiency compared to control subjects as assessed by polysomnography. 65 The relation between growth hormone and sleep in infants may not be fully understood, but a close interaction of the neuroendocrine and the chronobiological system has been shown in different populations. The (dys-)regulation of one system can affect the other.

In summary, while physical growth and weight gain in the first 2 years of life are largely predicted by birth weight, prenatal factors, and nutrition, 66 a growing body of evidence supports the critical role of infant sleep in growth. Several aspects of growth can be considered in relation to sleep, such as weight gain, stunting, and hormone release. However, the current literature focuses largely on weight gain and obesity rather than healthy growth. In particular, the detrimental impact of sleep deprivation on glucose tolerance, insulin sensitivity, and appetite-regulating hormones has been widely reviewed. In that context, infant and child sleep seems to provide a modifiable and thus promising target for obesity prevention, especially when regarded within multicomponent approaches. It is to be noted that most studies rely on parental report measures, and the quantification of sleep is usually converted to express hours of sleep; objective methods like actigraphy however gain more and more in relevance. Influencers for the sleep–growth relation, especially in infants and young children, include gender, prematurity, health conditions like allergies, nutritional factors like iron deficiencies, energy intake or feeding paradigm, and nighttime versus daytime sleep. 43 , 47 , 67

General discussion

Overall, the review of recent literature highlights that normative variations in infant sleep play an important role in cognitive development and physical growth. Studies on cognition show that individual differences in sleep quantity and quality are particularly important for the development of memory, language, and executive functions. Studies on physical growth indicate the potential risk of sleep problems, in particular shorter sleep duration early in life, for overweight, obesity, or measures of adiposity in infants, toddlers, and preschool-age children.

The findings from this review in infants are in line with epidemiological evidence from studies in older children and adolescents, 29 , 68 – 73 and some associations suggest persisting impact beyond infancy and young childhood. Although normative variations in habitual sleep in infants may be important for development, the review showed little consistency across the studies with regard to the component of sleep investigated (i.e. night sleep duration, daytime napping, night awakenings, etc.). This makes comparisons of studies and the generalization of the findings difficult and may likely be due to different methodologies used across studies. Many tools are available for assessing infant’s and young children’s sleep with different strengths and limitations. Questionnaires and sleep diaries are cost-efficient and can be administered to a large participant pool; however, these measures are also more subjective and less accurate in estimating sleep parameters when used as stand-alone measures. In contrast, sleep polysomnography and actigraphy provide more accurate and objective assessments of sleep, but are often very costly. While polysomnography requires the placement of electrodes by specialist staff and the children to stay overnight at a sleep lab, actigraphy watch may be worn by the children at home for longer periods of time, 74 , 75 and is therefore particularly useful for an objective assessment of sleep in infants and young children or when conducting sleep assessments in large samples as it enables nonintrusive measurement of sleep in one’s natural environment. 76 Hence, it would also be useful for future longitudinal studies to incorporate more objective sleep measures like actigraphy for at least a subsample of participants. Still, particular challenges occur even with more objective measures; for example, individual differences in sleep arrangements 77 such as falling asleep alone versus being rocked to sleep may interfere with the accuracy of the collected data. Therefore, it is also important to consider these methodological differences and individual differences when measuring infant sleep. Overall, a combination of approaches such as using questionnaires and diaries for a large sample and validating data with actigraphy in a smaller subsample may be most promising and yet feasible. Amongst the reviewed studies where both actigraphy and questionnaire data were collected at the same time point, researchers found positive associations between infants’ sleep actigraphy data and general cognitive development, 34 , 35 but no equivalent findings with questionnaire data. With regard to weight gain, most findings are based on parent report and questionnaire measures and largely point towards shorter sleep duration being linked to higher body size measures. Only three studies used actigraphy 35 , 43 and one study a sleep-monitoring device 44 and resulted in conflicting findings.

With regard to study designs, most reviewed studies used cross-sectional and observational designs with infants sampled at different ages. This may be a limitation as both sleep and neurodevelopment are very age-dependent and vary across different developmental stages due to their highly dynamic nature. Alternatively, longitudinal sleep and development assessments with repeated measurements for the same individuals at various time points may allow for a better understanding of developmental trajectories in those domains. Future work would benefit from trajectory studies with objective data (such as actigraphy and polysomnography) from infancy onwards, to detect the role of early infant sleep on later outcomes. Only two of the reviewed studies investigated the effect of sleep-related interventions and only with regard to weight gain. 48 , 50 While the longer (1 year) intervention trial that targeted multiple parental behaviors in the intervention resulted in a positive effect on lower weight-for-length percentiles at 1 year of life, the shorter (2 months) trial targeting behavioral sleep strategies did not show any effects on growth parameters at 6 years of life. In the absence of a bigger body of evidence, no recommendations can be made; however, sleep-related multicomponent interventions may be promising for supporting or improving healthy infant and child development.

Notably, some studies 25 , 33 did not control for known confounding variables such as socioeconomic status, 73 maternal mental health, 78 and parenting effects or effects of bedtime routines, 79 which may explain some of the variations in the cognition-related findings. It would moreover be interesting to explore the role of gender in sleep and cognitive and physical growth outcomes. Gender differences have been reported for sleep and growth; for example, shorter sleep duration was associated with larger body size measures in 6-month-old infant girls but not boys. 43 Although the scope of this review excluded studies on sleep disorders, conditions such as sleep-disordered breathing symptoms have been reported to lead to differences in cognitive outcomes. Recent studies found that infants with sleep-disordered breathing or primary snoring problems performed poorer on BSID scales as compared to age-matched controls. 80 – 83 Therefore, in addition to understanding the role of “normal” infant sleep in cognitive development and physical growth, more research on the impact of infant sleep disorders on cognitive, behavioral, and growth outcomes may be desirable.

Infant sleep is a particularly interesting field of research due to its dynamic trajectories, the developmental changes that occur during this period, and the interaction with other developmental domains. More specifically, we reviewed the association between infant sleep and cognition as well as physical growth. From the reviewed literature, we conclude that sleep plays a key role in those domains with its maturation paralleling, preceding, as well as resulting from interactions with cognitive and physical maturation. Exact mechanisms have not been the focus of this review and still remain to be understood; however, the maturation of central nervous system structures like the hypothalamus or the neurotransmitter system underlies both cognitive development and the regulation of sleep/wake cycles. 84

For future research, a combination of objective and subjective methods of sleep assessment is desirable, especially in the longitudinal exploration of both quantitative and qualitative aspects of sleep and infant development. From the cross-sectional studies, it is not possible to draw strong causal links between the two based on existing literature. For future studies, we propose to adopt a trajectory design which may reflect better the maturation and dynamic development, especially at young ages. It may furthermore improve the predictability of long-term effects on health and development compared to the predictability of cross-sectional time-point estimates as well as enabling us to examine the effects of cumulative sleep as compared to critical periods in the above relation. This is important to understand as sleep is one early life factor that can be targeted for interventions to optimize early development.

Nora Schneider is an employee of Nestec Ltd. The authors report no other conflicts of interest in this work.

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August 5, 2024

Sleep Training Won’t Hurt a Parent or Baby. Bad Sleep Will

Despite conflicting advice, letting your baby “cry it out” can help parents and babies alike

By Jasmine Mote

Having a baby can be exhausting, especially when they won't go to sleep.

South_agency/Getty Images

This piece is part of Scientific American’s column The Science of Parenting. For more, go here .

It was 3 A.M., and my seven-month-old would not stay asleep. She didn’t want to nurse. She cried when I offered her a bottle. I bounced her in my arms, softly singing the Cure’s Just Like Heaven . That didn’t help, either.

With a sigh I put her in her crib, left the room and set my phone timer for 15 minutes. I would check on her again after my alarm buzzed.

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I was sleep training my baby.

Sleep training has become the third rail of parenting conversations , with fierce defenders and opponents on either side. Some claim it’s a miracle. Others liken it to torture—for both the baby and the parent. Still others aren’t convinced it will actually “work.”

Sleep training is a catchall term for any behavioral intervention intended to improve a child’s ability to fall and stay asleep independently, often as it relates to sleep in infants (those under one year old). The idea is to avoid reinforcing the baby’s cries and yells for attention at bedtime, ultimately allowing those behaviors to fade, or go extinct, over time. Practices vary, from setting a structured bedtime routine to what is commonly referred to as “cry it out” (considered full extinction), where caregivers allow a baby to cry until the baby falls asleep. My family chose a version of the Ferber method (called graduated extinction), where we initially comforted our baby when she cried but slowly increased the amount of time between her cry and when we intervened.

Parents may not ask for or take advice regarding sleep training their child for many reasons. The dread of enduring crying or fears around bonding with one’s baby are often cited as main barriers for parents to sleep train . Conflicting information abounds, as one study found that parenting advice books about sleep had authors with a broad range of backgrounds, nearly half lacking professional credentials in medicine, counseling or academic research; the books’ advice varied widely as well, with some endorsing full extinction and others opposing it.

Overall the evidence suggests that sleep training (broadly defined) is safe and effective at addressing sleep difficulties. Multiple reviews that summarize all the available research on sleep training show that these practices improve sleep in children, from those under six months through five years old. “Cry it out” is particularly effective, though the evidence supports a range of practices that vary in how much crying a parent wants to tolerate.

Despite the evidence, maybe there’s a question still nagging at you: Am I a bad parent if I let my baby suffer just so I can get some shut-eye?

I’m here to convince you that sleep is not a luxury, and a desire for sleep is anything but selfish.

Poor sleep during the first year of a baby’s life is related to an increased risk of mothers developing postpartum depression, a condition that affects approximately one in six women . Postpartum depression can involve feelings of sadness, guilt and lack of enjoyment in everyday things, making it difficult for moms to take care of themselves and their children. To make matters worse, depression can lead to insomnia, which exacerbates depression, creating a terrible catch-22. When moms are depressed, babies sleep worse too . Further, when moms get poor sleep, other caregivers suffer: One study found that when mothers had poor sleep at six months postpartum, both mothers and fathers reported more depression symptoms six months later.

For some moms, getting enough sleep could be a matter of life and death. Suicide is one of the leading causes of death for new mothers, and sleep difficulties can exacerbate suicidal thoughts for mothers experiencing postpartum depression.

Sleep training may help break this cycle. Researchers in Australia conducted one of the largest studies to assess the long-term impacts of sleep training in over 300 families. Mothers were randomly assigned to either receive guidance on sleep-training practices or receive care as usual from their medical team when their babies were eight to 10 months old. Mothers who sleep trained experienced less severe depression symptoms compared with other mothers when their children were 10 months, 12 months and two years old . These children also had fewer sleep difficulties compared to other children.

Other research has assessed sleep training and maternal mental health in a rigorous fashion, with varying results. Some studies find that it is related to reduced maternal depression , while others do not . Researchers define sleep training in many ways, making it difficult to know if a specific method is more or less effective than others at addressing mental health.

The benefits of sleep training may be specific to the baby and toddler years. Those same Australian researchers found that when children were six years old, there was no longer a relationship between sleep training as a baby and maternal mental health. In fact, sleep training at eight months didn’t seem to matter on a host of outcomes when children were six, including how well children got along with their parents and child behavioral issues. This is good news: Sleep training does not appear to have long-term negative consequences on children or parents.

Sleep training does not cure depression. Support from a mental health care provider trained in postpartum concerns or insomnia may be essential if you’re experiencing difficulties as a new parent. Additionally, there may be medical, practical or personal reasons why sleep training is not in the best interest of your family. Some methods of sleep training may not work for a child with health needs requiring a specific nighttime feeding regiment, or practical when a baby shares a room with a sibling or family member. Whether or not you sleep train your child has no bearing on your worth as a parent (or person). I’m not a callous and unloving mother because I sleep trained my child, and you’re not an overly permissive or weak mother if you don’t.

When we argue about safe and effective parenting choices like sleep training, we are perpetuating the myth that what makes a good parent is sacrifice—sacrificing our mental health, our preferences, our sleep. These arguments make us unnecessarily question our worth as parents, when perhaps the most important thing we could do for our mental health is to have more confidence in our parenting abilities. Indeed, one study found that when mothers had higher self-efficacy (i.e., they thought they were doing great as a parent), their mental health was unrelated to how well their child slept.

That was the most surprising gift that sleep training provided me: confidence. Confidence in myself as a new mother and the notion that my needs were not in direct conflict with my baby’s needs. I learned to stop letting my insecurity about being a “good mom,” whatever that means, bully me into thinking that my mental health does not matter.

I want that for all parents. That, and a good night’s sleep.

My phone buzzed. My daughter was still awake, crying. I took a deep breath. I went in, comforted her, kissed her tiny forehead and put her back down in the crib. I set my phone timer again, this time for 20 minutes. She fell asleep. Eventually so did I.

This is an opinion and analysis article, and the views expressed by the author or authors are not necessarily those of Scientific American.

A parent’s guide to sleep training infants and toddlers

Video transcript.

[MUSIC PLAYING] As your baby starts to grow, questions about sleep training will probably come up. Is sleep training safe? Is it effective? How would I even get started? We spoke to Dr. Angela Holliday-Bell, a UChicago Medicine Medical Group pediatrician and sleep specialist to help debunk some common myths.

Myth number one, sleep training teaches my child to stay asleep all night. Actually, it's natural to wake up multiple times throughout the night even as adults. Sleep training is about building tools to help your child fall back asleep on their own.

Myth number two, sleep training is harmful to my child. This is a common misperception. However, sleep training can have major benefits. A study by the American Academy of Pediatrics found no difference in attachment style or behavioral problems, and babies who completed sleep training showed decreased stress levels.

Myth number three, all sleep training methods are the same. From the cry-it-out method to the graduated-Ferber method, to the moving chair there are a wide variety of techniques. Parents should find the approach that works for them and their baby.

Myth number four, toddlers can't be sleep trained. With toddlers, you just need a different approach because you need their buy in. Try focusing on positive reinforcement like a sticker or other fun reward for staying in bed without getting up at night. And here's a tip. Consistency is key. Your baby is learning and needs to understand what to expect at night. So the best sleep training method is the one that all parents and caregivers will stick with.

To schedule an appointment with Dr. Holiday-Bell and view our team of pediatricians, visit uchicagomedicine.org/pediatricians.

[MUSIC PLAYING]

Sleep training is a commonly misunderstood topic among new parents.

But with proper preparation and consistency, it can be a valuable asset in improving overnight sleep for both you and your child.

Below are answers to frequent questions I get from parents.

What is sleep training?

Sleep training involves giving your infant, toddler or child the tools they need to fall asleep at the beginning of the night and back to sleep in the middle of the night without parental intervention.

A common misperception is that sleep training is teaching your child to sleep straight through the night. That's untrue. Even we adults wake up multiple times at night. This is part of the process as we cycle from one sleep phase to the next.

Sleep training your child is more about helping them develop the independent skills they need to fall back asleep.

What is the best age and weight to start sleep training your baby?

The best age and weight to begin sleep training varies, since every baby develops differently.

Your child’s pediatrician  can help you decide when the time is right. In general, 4 months and 14 pounds is a good time to start.

Babies do not actually develop their own melatonin or regulation of their sleep cycles until around 3+ months. Up to then, their ability to fully distinguish between day and night and connect sleep cycles to night is limited.

Generally, 14 pounds is a good weight because the baby may not need overnight feedings at this time.

What is the best sleep training method?

The best sleep training method is the one you and your partner can maintain until the pattern becomes habit.

For example, many families try the cry-it-out method, where they let the baby cry without intervention or overnight feeds. You often see results quickly with this technique but some parents wind up intervening every now and then.

Inconsistency can stop any progress being made. Your baby is looking to learn and needs to understand what to expect.

So the right method is the one where you and your partner, if a partner is involved, can find a routine and be consistent.

How long does sleep training usually take?

This can depend on the baby and the chosen method, since each baby is a little different.

In general, the cry-it-out method tends to work in as little as three to four days.

The Ferber method, also known as "graduated extinction," usually takes somewhere between seven to 10 days. In this case, the parent comes to check on the baby at longer intervals over time.

More lenient methods can take up to four weeks. These include the chair method, where a parent sits in a chair by the crib/bed at night until the child falls asleep. The parent gradually moves the chair further away nightly so the baby learns to fall asleep with less interaction.

Will sleep training harm my child?

When done with the right preparation and in the right environment, sleep training is safe and effective. In fact, the benefits to children and parents are major.

For instance, The American Academy of Pediatrics conducted a study where infants were divided into two groups. One group went through sleep training, the other did not.

The study measured:

• Cortisol levels – a key marker of stress - in the baby
• Parental satisfaction and stress levels
• Attachment styles once the baby reached 1 year of age

Results found that babies in the sleep training group had decreased cortisol levels by the end of the training. And there was no difference found in attachment style or behavioral problems between the sleep trained group and the non-trained group.

Sleep training can help babies learn how to self-soothe and cope with stress experienced whether parents intervene or not.

Can I sleep train my toddler?

Sleep training a toddler may look different from sleep training an infant, but it’s possible and beneficial.

It can be more difficult for a toddler because they have a voice and they can get up and leave the bed. The cry-it-out method may not work.

However, toddlers understand rewards and motivation. Get their buy-in and use positive reinforcement, like saying, "If you stay in your bed without getting up at night, you get a sticker.”

That kind of praise for accomplishing a task is really motivating to them.

When should you contact your child’s pediatrician about sleep training?

If you’re interested in sleep training, bring it up to your child’s pediatrician first.

They can ensure the baby is ready, healthy, and does not need those overnight feeds.

They can also answer any questions or concerns before or during the training process. Your pediatrician can help make sure your baby is thriving and growing.

*Angela Holliday-Bell, MD, is a UChicago Medicine Medical Group provider. UChicago Medicine Medical Group is comprised of UCM Care Network Medical Group, Inc. and Primary Healthcare Associates, S.C. UChicago Medicine Medical Group providers are not employees or agents of The University of Chicago Medical Center, The University of Chicago, or UChicago Medicine Medical Group - Homewood.

Angela Holliday-Bell, MD*

Angela Holliday-Bell, MD is a UChicago Medicine Medical Group provider and a board-certified pediatrician. Her expertise includes providing infant and toddler sleep training and managing behavioral insomnia in kids.

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Sleep Training

• PMID: 32155274
• DOI: 10.3928/19382359-20200218-01

Adequate sleep in infancy and beyond is important for development; however, many children are not sleeping the recommended amount. During the first few years of childhood, infants are frequently seen in the pediatric office for well-visits and a myriad of other concerns, including sleep difficulties. As such, pediatricians should be adequately prepared to address these concerns. This article aims to provide clinicians with a basic knowledge of sleep physiology, sleep patterns and development, and current guidelines and options available for parents to address these issues. [Pediatr Ann. 2020;49(3):e101-e105.].

Copyright 2020, SLACK Incorporated.

Publication types

• Child, Preschool
• Infant, Newborn
• Sleep Hygiene*
• Sleep Wake Disorders* / therapy
• Sleep* / physiology