A recent interesting white paper on sleep by Cassels et al 2013 published by Praeclarus Press made some research references to ‘normal’ infant sleep, especially in relation to breastfeeding and bedsharing. All references are in the original article at: http://www.praeclaruspress.com/WhitePapers/praeclarus_press_normal_infant_sleep.pdf
Many mothers seem to be very concerned and worried about their baby’s sleep patterns (or lack of one) leading to them not getting their ‘eight hours’ which may not be normal for adult humans either. A sleep historian, Roger Ekirch, author of ‘At Day's Close: Night in Times Past’ maintains humans naturally slept for two ‘four-hour blocks’, getting up in the middle of this time to do tasks and then going back to sleep. This behaviour would now be considered ‘insomnia’ with medication prescribed so people could get their full 8 hours’ sleep again. Some of the most interesting references in this article are:
What is normal?
The notion of 8 hours’ sleep may be more to do with the industrial revolution and the invention of the electric light bulb, according to Ekirch, and nothing to do with our natural sleep rhythms. Babies, who don’t have to get up in the morning to go to work, may be more in tune with natural sleep patterns and it is the adults who are doing it all wrong!
Formula feeding does not guarantee more sleep!
Cassels et al. note that with human milk containing less protein and fat than cow’s milk making it necessary for babies to feed more often, formula milk also contains other additives that make it more difficult and slower to digest inducing a much deeper sleep making it more difficult for babies to arouse. However, the use of formula does not necessarily result in babies sleeping more overall (Doan, Gardiner, Gay, & Lee, 2007; Kendall-Tackett, Cong, & Hale, 2011 cited in Cassels et al., 2013) with Weinraub et al. 2012 maintaining that all babies wake up regularly at night regardless of how they are fed.
Breastfeeding mothers get more sleep!
Kendall-Tackett et al. 2011 found that breastfeeding mothers get 45 minutes more sleep than either formula-only or mixed-feeding mothers with Doan (2007) suggesting that supplementing results in less sleep overall than even formula only.
Babies don’t have a pattern!
Babies who had been sleeping for long periods may suddenly wake more often between 6 to 12 months (Scher, 1991, 2001)with one longitudinal study finding that between 3 and 42 months there was no stability in waking or duration for any babies (Scher, Epstein, & Tirosh, 2004).
Some babies go to bed with their parents!
One study noted that babies in Asia tend to go to bed at the same time as their parents with Hong Kong babies going to bed at around 10.17pm as opposed to babies in the West who go at 8.44pm – these are average figures (Mindell, Sadeh, Wiegand, How, & Goh, 2010).
Bed-sharing does not harm the marital relationship!
Recent research has found that there is no harm to the marital relationship when bedsharing is intentional – it seems that it is only when bedsharing occurs because the baby is not perceived to be sleeping that it becomes a problem (Messmer, Miller, & Yu, 2012).
Night-time breastfeeding promotes sleep!
Night-time breastmilk contains tryptophan (sleep-inducing amino acid) while amino-acids are also credited in promoting serotonin synthesis (Delgado, 2006; Goldman, 1983; Lien, 2003): serotonin keeps one happy and helps sleep-wake cycles (Somer, 2009).
It is normal for infants to prefer to sleep in contact with others
Cassels et al. note a study which suggested that babies like to wake up in the same environment that they fell asleep in as otherwise they wake up crying, especially if they fell asleep in mother’s arms at her breast and wake up alone in a cot or even another room (Anders, Halpern, & Hua, 1992). Most adults probably don’t like waking up somewhere strange either!
(cited in original article by Cassels et al 2013 online at http://praeclaruspress.com/wp-content/uploads/2013/08/praeclarus-press-normal-infant-sleep-2.pdf
Anders, T.F., Halpern, L.F., & Hua, J. (1992). Sleeping through the night: a developmental perspective. Pediatrics, 90, 554-560.
Cassels,T. ; Ockwell-Smith, S.; Middlemiss, W.; Kendall-Tackett, K.; Stevens , H.; McKenna, J. & Narvaez, D. 2013. Is Your Baby’s Sleep a Problem? Or Is It Just Normal? Mother-Baby Sleep Experts Weigh in on Normal Infant Sleep. A Praeclarus Press White Paper. Published online August 22, 2013 at www.PraeclarusPress.com.
Delgado, P.L. (2006). Monoamine depletion studies: Implications for antidepressant discontinuation syndrome. Journal of Clinical Psychiatry, 67(4), 22-26.
Doan, T., Gardiner, A., Gay, C. L., & Lee, K. A. (2007). Breast-feeding increases sleep duration of new parents. Journal of Perinatal & Neonatal Nursing, 21, 200-206.
Goldman, A. S. (1993). The immune system of human milk: Antimicrobial anti-inflammatory and immunomodulating properties. Pediatric Infectious Disease Journal, 12(8), 664-671.
Lien, E.L. (2003). Infant formulas with increased concentrations of α-lactalbumin. American Journal of Clinical Nutrition, 77(6), 1555S-1558S.
Kendall-Tackett, K. A., Cong, Z., & Hale, T. W. (2011). The effect of feeding method on sleep duration, maternal well-being, and postpartum depression. Clinical Lactation, 2(2), 22-26.
Mindell, J. A., Sadeh, A., Wiegand, B., How, T. H., & Goh, D. Y. T. (2010). Cross-cultural differences in infant and toddler sleep. Sleep Medicine, 11, 274-280.
Mindell, J. A., Telofski, L. S., Weigand, B., & Kurtz, E. S. (2009). A nightly bedtime routine: impact on sleep in young children and maternal mood. Sleep, 32, 599-606.
Scher, A. (1991). A longitudinal study of night waking in the first year. Child: Care, Health and Development, 17, 295-302.
Scher, A. (2001). Attachment and sleep: A study of night-waking in 12-month-old infants. Developmental Psychobiology, 38, 274-285.
Somer, E. (2009). Eat your way to happiness. New York: Harlequin.