GOLD Lactation Conference News

Kathleen Kendall-TackettAuthor: Kathleen Kendall-Tackett, Ph.D., IBCLC, FAPA

A recent article published in Pediatrics described a 5-year follow-up of a study of a sleep training program. In this program, parents were instructed to either check on their infants, but not respond to their crying or to “camp out” by sitting next to their crying babies without responding (Price, Wake et al. 2012). The control group received no instruction in how to handle nighttime crying. The authors concluded that there was no there was no apparent harm, and no apparent benefit, to this approach. Despite these tepid findings, this study made headlines for weeks, with news articles indicating that sleep training was “safe.” Some articles went so far as to recommend it as a strategy for tired new parents.

The reaction to this article indicates that sleep training continues to be a popular parenting philosophy, which has its roots in American Behaviorism. In the 1920s, John B. Watson, the father of American Behaviorism, put forth the idea that children needed to be raised without “excessive” affection. According to Watson, children’s behavior could be engineered, or shaped, through a series of punishments and reinforcements. Reinforcing a behavior meant that you were increasing the likelihood that is would re-occur. If you want a behavior to stop, don’t “reinforce” it. Under this school of thought, if you pick up a crying baby, you are just reinforcing the likelihood that the baby will cry more often—especially at night.

Is this a benign approach? The answer is, unfortunately, no.
Babies left to cry have elevated levels of the stress hormone cortisol. Over the past two decades, research in neuroscience has revealed that chronically elevated cortisol was harmful for brain cells. This was true for adults. And it was especially true for children under the age of five, whose brains are highly malleable, and therefore highly vulnerable to stress.

Sapolsky (1996) authored one of the classic articles on the effects of stress in the journal Science. In this article, he described the impact of the stress hormone cortisol on the hippocampus, the section of the brain involved in learning and memory. Those who experienced ongoing chronic stress or depression (which elevated cortisol levels), had smaller hippocampi than those without stress or depression. Bremner and others have found a similar pattern with combat vets and sexual abuse survivors with PTSD (Bremner 2006). There were many other studies with similar findings. But the bottom line is this: chronically elevated cortisol levels harms brain cells.

In addition, chronic stress in infancy and early childhood has been identified as a major contributor to adult health problems. In 2009, Shonkoff and colleagues published a review in the Journal of the American Medical Association, which stated that “adult disease prevention begins with reducing early toxic stress.” They described how stress in infancy was related to diseases in adults, such as heart disease, diabetes, and even cancer (Shonkoff, Boyce et al. 2009).

Sleep training and cry-it-out techniques can also potentially harm breastfeeding. Mothers who are told to ignore their babies’ cries in some instances will find it more difficult to be responsive to their infants in other instances. This is a case of culture overriding a mother’s hardwired response to her baby. Spacing out feedings and/or stopping night feedings at some arbitrary age will have a direct impact on her milk supply, opening the door to milk-supply issues, decreased weight gain, increased supplementation, and possibly failure to thrive.

Taken together, the results of these and other recent studies indicate that sleep training is not a benign parenting technique. Parents should be presented with ways to calm crying babies, and told about the importance of responsiveness to their babies’ cries in their babies’ psychological, social, and emotional development. Responsiveness is also essential to initiating and sustaining breastfeeding over the first year.

Bremner, J. D. (2006). "Stress and brain atrophy." CNS and Neurological Disorders Drug Targets 5(5): 512.
Price, A. M. H., et al. (2012) Five-year follow-up of harms and benefits of behavioral infant sleep intervention: Randomized trial. Pediatrics 130,
Sapolsky, R. M. (1996). "Why stress is bad for your brain." Science 273: 749-750.
Shonkoff, J. P., et al. (2009). "Neuroscience, molecular biology, and the childhood roots of health disparities: building a new framework for health promotion and disease prevention." JAMA 301(21): 2252-2259.

A previous Lactation Conference Speaker, Kathleen Kendall-Tackett will be a returning Alumni Speaker at the GOLD Lactation Alumni Presentations happening between January 27 and February 13th.