Cry It Out Infant Sleep Training

(Public domain)

Recently there has been a discussion about infant sleep training on the CNML Facebook group, so I thought it would be helpful to provide a post on the topic.

First, what is cry it out infant sleep training? It involves purposely letting baby cry it out at night in order to condition baby to sleep for longer and longer periods of time. The goal is to encourage babies to learn to self soothe and be able to get back to sleep without the assistance of a parent.

The Academy of Breastfeeding Medicine has a new protocol published in 2023 that addresses this topic: Physiologic Infant Care - Managing Nighttime Breastfeeding in Young Infants. Here are the main conclusions:

• Studies have shown that infants’ and parents’ stress levels are higher when letting baby cry it out. In some of the studies, saliva samples were taken and cortisol levels were shown to be higher while baby is crying it out. Even on subsequent nights when baby is not crying, cortisol levels remained higher.
• Studies have shown that sleep training is not effective. It does not improve the sleep of infants. Infants still wake up but just do not signal their parents when they awake. Therefore, they are not really sleeping for longer periods. Something to ponder: are the sleep trained babies learning to get back to sleep better on their own or have they just been conditioned to not cry when they need something at night?
• For infants under six months of age, sleep training can have a negative effect on breastfeeding and lead to early weaning because mom and baby are separated. Also, the risk of SIDS increases due to baby being placed in a separate room.
• There was a randomly controlled study done in 2016 involving 43 infants that were assigned to different methods of cry it out sleep training plus a control group. The results of the study did not show emotional or behavioral problems in the infants 12 months later. However, some issues with the study were: the saliva samples to compare cortisol levels were taken a week after the crying episodes, not during or immediately after the crying episodes, and the number of infants in the study was too small to generalize the results to the larger population. Also, please note that the infants in the study were six months or older.

Other things to consider

• Babies do not understand object permanence - knowing that a person or object is still there even when he or she cannot see it - until late in the first year of life.
• It is physiologically normal for babies to nurse every 2-3 hours or more often partially because breast milk is quickly digested. Plus, babies consume a large portion of their daily calories at night. By reducing the number of feedings at night, there is potential for reduced milk supply. Also, nursing on demand at night is helpful for natural child spacing.
• Even researchers who are not necessarily against cry it out sleep training caution against using it on babies younger than six months of age or with babies more prone to psychological damage such as those who were previously in foster care or have certain temperaments (according to an article published by BBC).
• Moms and babies have slept close to each other for thousands of years. Infant sleep training is a very new approach to nighttime parenting since around the time of the Industrial Revolution and is not present in all cultures around the world today - mostly only in North America, Australia and parts of Europe (according to the BBC article mentioned above).
• Babies want and need comfort from their parents - even at night.
• One alternative to letting your baby cry it out is Safe co-sleeping. At least one study has shown that bedsharing helps breastfeeding moms get a little bit more sleep on average than having baby sleep somewhere else.

For more information, you might like to read Dr. Sears’s book, Nighttime Parenting, or read more about this topic on his website.

Written by Gina Peterson