The Reality of Infant Sleep March 09, 2014 20:55
Written By Michelle Roth, BA, LCCE, IBCLC
It’s 3am. You’re awake for the second time so far tonight, and your baby cries every time you set her back in the cradle. The same happened last night. When will she start to sleep more at night? Is there something you’re doing wrong – isn’t everyone else’s baby is already sleeping through the night? How are you going to manage if you don’t get some rest? Who would ever want to “sleep like a baby” if this is what it’s like? This isn’t at all the glowing picture you imagined before the baby was born …. Isn’t sleep deprivation a form of torture?
We’ve all been there. Parents-to-be hear about sleep deprivation during pregnancy. Everyone tells you to be prepared for it. But the reality of fragmented sleep is still a shock to the system. We may intellectually understand that babies will wake often, but we cannot grasp the impact of that until we are living through it. Is there a better way – before baby’s birth - to align parental expectations about infant sleep with the actuality of it?
As a new parent, you can start by considering how you typically slept before baby was born. Did you wake every now and then to look at the clock or adjust your blankets? Did you need to get up to use the bathroom or get a sip of water? Our babies are waking for those same reasons – comfort and companionship. And it’s a normal part of sleep – for the baby and for you. James McKenna, the lead researcher at the University of Notre Dame Mother-Baby Behavioral Sleep Laboratory, says humans are meant to be “biphasic sleepers” and it’s only within the last century that Western culture has consolidated sleep into a single block. In the past – as well as in other cultures today – people sleep for a short period, then spend a couple of hours awake, and finally finish their sleeping for a longer stretch, usually with a nap added during the day.
Next, parents need to keep in mind that human babies are born with only a fraction of their adult brain volume making them the most immature mammals neurologically, and they have a slow rate of maturation. So an infant’s caregivers need to act as regulators of all functions from elimination to eating to sleeping. A baby sleeping alone and for extended stretch
es, however, is a cultural phenomenon that came about in the last 100 years and is specific to Western culture. Biology doesn’t change that fast – and it may be that our cultural proscriptions are completely out of tune with what babies need biologically to survive and thrive. Babies are not programmed to sleep for extended periods, but we want them to fit into our ideal, thus the rise of “infant sleep problems.” The real problem may be our expectations, not the baby’s behaviors.
Let’s take a look at what we know about infant sleep. Newborn babies sleep 12 to 20 hours a day on average. They wake often, day and night, and rarely sleep longer than 3 hours at a time. Some babies have their days and nights confused. Helen Ball, of the Parent Infant Sleep Lab at Durham University in the UK, says this is to be expected. She writes that “infants are not born with functional circadian rhythms. Their sleep patterns begin to consolidate into a diurnal pattern only from around 3 months of age, with the body clock maturing between 6 and 12 months.” Galland and collegues agree, concluding that sleep-wake regulation and sleep states evolve rapidly during the first year of life with continued maturation across childhood. Because newborns do not have an established circadian rhythm, their sleep is distributed throughout the day and night with each period of sleep short because of feeding frequency. At around 10-12 weeks of age, the circadian rhythm begins to emerge, and infant sleep becomes increasingly nocturnal.
So, around 3 or 4 months, we can expect babies to begin to sleep more regularly, with most of that sleep at night when we’d like to sleep, as well.
Waking at night is also the product of sleep cycles – at the end of a cycle, we might arouse briefly before another starts. For infants, they may need their regulators (parents) to help them return to sleep. But there’s a huge disconnect between adult and infant sleep cycles. Adults move through five stages of sleep, beginning with deep sleep and ending with light, or REM, sleep after a 90-minute cycle. Over the course of a sleep, adults have more REM and less deep sleep. Infants, on the other hand, start their sleep in the lightest stage, REM sleep, which researchers think is necessary for brain development. After 20 minutes or so, they move into deep sleep, but start to arouse after a 60-minute sleep cycle. This difference in the length of the sleep cycles may mean that your baby is waking you before you get through your entire sleep cycle, making you feel more pronounced effects of sleep fragmentation. Interestingly, when breastfeeding mother-baby pairs cosleep, the start to have synchronous sleep cycles, which may mean a better quality of sleep for mom despite waking often to tend baby.
In their systematic review of literature pertaining to normal infant sleep patterns, Galland and colleagues admit that a major problem with the research is a lack of distinction between breast- or bottle-fed babies. We do, however, have a robust body of research about co-sleeping infants and breastfeeding thanks to researchers like McKenna and Ball who have created sleep labs to study the effects of shared sleep.
Their studies have provided huge insight into the safety of mother-infant co-sleeping, as well as the beneficial effect of nighttime breastfeeding.
Much of their work focuses on SIDS prevention, showing that co-sleeping, breastfeeding, and night waking might be protective for infants. In an early study, Mosko, Richard & McKenna looked at mother-infant pairs in a sleep laboratory. These dyads were recorded sharing sleep and sleeping apart, and comparisons were made. What they found was that, on the bedsharing night, infants had longer total sleep, more light sleep, and more arousals during deep sleep. Moms also had more light sleep, but no change in total sleep. The most interesting finding? Moms and babies had overlaps in arousal on the bedsharing night – so moms weren’t getting interrupted sleep, they were awakening briefly at the same time as baby and then returning to sleep. The researchers think this may serve as “practice” for baby in navigating sleep – again, the necessity of the caregiver to help baby regulate his or her system until the baby is neurologically ready to assume self-regulation.
An additional reason babies wake at night relates to hunger. Nils Bergman in a review of the literature found that newborns typically have a 20ml stomach capacity, and it takes about one hour for that 20ml of breastmilk to be digested. This gastric emptying time fits nicely with the length of an infant sleep cycle, leading one to believe that hourly waking and feeding is biologically appropriate for human babies.
What itall comes down to is that night waking is NORMAL for the human infant. The main problem is that our culture makes sleeping through the night seem like the norm. Researchers say caregivers’ expectations and behaviors that are at the source of infant sleep problems, so we need to help parents better understand normal sleep. Helen Ball agrees, saying we need to realign parental expectations with reality of newborn sleep. Night waking is not pathological, and extended periods of sleep are a developmental milestone – we should be helping parents “anticipate and cope” with this pattern.A recent article in Breastfeeding Review supports this assertion, concluding that
“New parents should be aware that infants' sleep is unlike that of adults and that meeting their infant's needs is likely to disrupt their own sleep. They will need to adjust their routine to manage their own sleep needs. “
So instead of leaning toward sleep training for infants, it’s more important to adapt your own behavior to better meet your baby’s biological potential. Researchers Douglas and Hill conclude that “we’re telling parents to do with their young babies exactly what we tell them not to do if they are adults experiencing insomnia themselves!” Tactics such as tracking how long or often the baby sleeps, and when the baby wakes, cause parents to resent infant intrusion on their own sleep.
So how can you as a parent learn a better method for dealing with sleep fragmentation and infant waking? First, educate yourself about normal infant sleep. Some great books include:
Helping Baby Sleep by Anni Gethin and Beth Macgregor
The No-Cry Sleep Solution by Elizabeth Pantley
Sleeping with your Baby by James McKenna
Good Nights by Jay Gordon
Sweet Dreams by Paul M. Fleiss
Nighttime Parenting and The Baby Sleep Book by William Sears
Then go with your instincts. If it seems like your baby is content and thriving, her sleep schedule is just right for her. Be aware of your own sleep deficit, and find ways to combat it. Sleep when your baby sleeps – or at least get horizontal and rest, even if you don’t actually sleep. Go to bed earlier yourself, so that you get a few extra minutes per day. Eat well, stay hydrated, and get exercise and fresh air every day. Most of all, remind yourself that this is temporary – your baby will grow and start to sleep more, and you will catch up on your sleep deficit without even realizing you’re doing it.
Ball H. (2013). Supporting parents who are worried about their newborn’s sleep. BMJ 346: f2344.
Bergman NJ. (2013). Neonatal stomach volume and physiology suggest feeding at 1-h intervals. Acta Paediatr 102(8):773-7.
Douglas PS & Hill PS. (2013). Behavioral Sleep Interventions in the First Six Months of Life do not Improve Outcomes for Mothers or Infants: A SystematicReview. J Dev Behav Pediatr 34: 497–507.
Galland BC, Taylor BJ, Elder DE, Herbison P. (2012). Normal sleep patterns in infants and children: A systematic review of observational studies. Sleep Medicine Reviews, 16(3): 213-222.
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McKenna JJ. (2001). Part I: Why we never ask “Is it safe for infants to sleep alone?”: Historical origins of scientific bias in the besharing SIDS/SUDI ‘debate.’ ABM News and Views, 7(4):32,38.
Mosko S, Richard C, and McKenna JJ. (1997). Infant Arousals During Mother-Infant Bed Sharing: Implications for Infant Sleep and SIDS Research. Pediatrics 100(2): 841-849.
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Tsai SY, Hu WY, Lee YL, Wu CY. (2013). Infant sleep problems: A qualitative analysis of first-time mothers' coping experience. Midwifery. 2013 Aug 14. [ePub ahead of print]