The Hidden Risks of Early Sleep Training: What Science Tells Us

A  published review in the Journal of Developmental and Behavioral Pediatrics has illuminated an important yet often overlooked issue—early sleep training in young infants, specifically those under six months of age. This comprehensive review paper compiled and analyzed studies spanning 20 years, from 1993 to 2013, to evaluate the effects of early sleep training on infants younger than six months. The findings highlight significant risks and counter the widespread belief that early sleep training is beneficial for infant development and maternal mental health.

Why Is Early Sleep Training a Concern?

Many doctors, sleep experts, and clinics begin promoting sleep training as early as 3 or 4 months, and sometimes even earlier. This happens during a crucial time of infant development, often called the “fourth trimester,” when infants are still adapting to life outside the womb. Opponents of early sleep training argue that it interferes with the infant’s naturally developing circadian rhythms, creates undue stress, and can even undermine breastfeeding success.

Yet, proponents of early sleep training have largely insisted that its critics bear the burden of proving harm. Thanks to this review, we now have a clearer picture of why early sleep training may not be advisable.

What the Science Says: Key Findings

The study, conducted by Drs. Pamela Douglas and Peter Hill from the University of Queensland in Australia reviewed 43 studies on early sleep training. The researchers looked at a variety of sleep training methods, including separating feeding from sleep, teaching infants to “self-settle” without food or touch, scheduling infant sleep, and reducing daytime stimulation. Here are some of the key findings:

1. Longer Sleep Durations But No Reduction in Crying: Early sleep training (within the first 12 weeks) may result in longer sleep durations for infants, but it does not reduce infant crying. This finding is significant because the primary reason parents seek sleep training is to reduce crying and improve sleep.
2. No Link Between Night Wakings and Long-term Problems: Breastfed infants who experience frequent night wakings were found to have no long-term sleep or behavioral issues. Furthermore, infants who have sleep disturbances at six months, without intervention, grow up with completely normal mental health in young adulthood. This challenges the notion that night wakings lead to future developmental problems.
3. Maternal Depression and Infant Sleep: Sleep training before six months was not found to reduce maternal depression. The study showed that maternal sleep problems are more closely linked to depression rather than infant sleep. It was maternal depression that predicted longer infant awakenings, rather than the other way around.
4. Breastfeeding and Maternal Mental Health: Mothers who breastfeed tend to wake more often during the night, but they report better sleep quality and lower rates of postpartum depression. Importantly, separating feeding from sleep (decoupling) in infants under six months was linked to increased breastfeeding failure, further underscoring the risks.
5. Negative Impact of Rigid Sleep Schedules: Placing infants on rigid sleep schedules was associated with a threefold increase in behavioral problems at six months and double the amount of crying compared to infants receiving cue-based care. This suggests that a flexible, responsive approach is better for infant well-being.
6. Dark Room Daytime Sleep and Increased SIDS Risk: Placing an infant in a dark room during the day with the idea that they need more sleep can inhibit nighttime sleep consolidation, leading to more frequent night wakings. It also increases the risk of Sudden Infant Death Syndrome (SIDS). Additionally, such practices hinder the mother’s ability to establish a healthy daytime rhythm, negatively affecting her mental health.
7. Parental Anxiety and Focus on Sleep Metrics: The study found that focusing on sleep metrics—such as the duration of infant sleep, intervals between sleep, and number of wakings—increased parental anxiety. Ironically, this anxiety can lead to worse sleep for both the infant and the parents.
8. Lack of Evidence for Preventative Sleep Training: Most families did not report sleep issues in the first six months of their child’s life. However, many parents were advised to adopt behavioral techniques as preventative measures against potential future sleep problems. The review concluded that there is no evidence to support the effectiveness of these early interventions, and they may create unnecessary stress.

A Holistic Approach Is Needed

So, what should parents do instead? The authors of the review advocate for a holistic approach to managing infant sleep issues, one that avoids sleep training and behavioral techniques during the first six months. Instead, parents should be educated about cue-based care, which means responding to the baby’s signals for sleep, food, and comfort. It also involves fostering parent-child synchrony and healthy daytime rhythms, while addressing parental anxiety about sleep and normal infant crying.

Feeding difficulties should also be thoroughly assessed, as they are a common cause of unsettled infant behavior. Parents should be given all the necessary support to overcome these challenges before resorting to any sleep interventions.

The Cost of Sleep Training: Is It Worth It?

This comprehensive review makes it clear that early sleep training lacks solid scientific backing and carries a risk of harm. After 20 years of research, the evidence supports the biological norm of flexible, responsive care over rigid, behavioral sleep training in the early months of an infant’s life.

Had we prioritized biological norms and cue-based care over promoting sleep training without adequate evidence, we could have saved countless families from unnecessary stress and anxiety. As this review shows, early sleep training not only fails to deliver on its promises but can also have lasting negative impacts on both infants and parents.

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A Call to Reconsider Early Sleep Training

It’s time for sleep trainers, baby “experts,” and healthcare providers to reconsider their stance on early sleep training. Rather than pushing interventions that interfere with natural development, we should focus on supporting parents in a way that respects the biological needs of their babies and reduces parental anxiety through education and supportive care.

For parents currently navigating the often-challenging waters of infant sleep, remember that your baby’s wakefulness and needs are normal. With the right support, you can create a nurturing environment that supports both your child’s development and your own mental well-being, without resorting to potentially harmful practices.