A new study suggests that letting babies cry at night may not cause the emotional, behavioural or attachment issues that some parents worry about during sleep training.
The study, out of Australia’s Flinders University and published in the journal Pediatrics this week, showed that letting babies cry as a means to teach them to self-soothe .
The debate over whether to allow babies to cry themselves to sleep, or whether to immediately respond to their cries, can often spark a heated debate on both sides.
Many parents are familiar with the phrase "cry-it-out," which refers to a sleep-training method that involves ignoring a baby's cry until they fall asleep on their own. By allowing babies to cry, some individuals believe the children learn to self-soothe.
On the other side of the spectrum are those that believe by not responding to a baby's cries, a child may lose trust in his or her parents, which could lead to emotional and behavioural issues down the road.
In his study, psychologist Michael Gradisar – "graduated extinction" and a "gentler" method known as "bedtime fading."
Graduated extinction is a method of controlled crying that involves gradually delaying parents' response to their baby's cry. Bedtime fading involves parents gradually delaying a baby's bedtime each night in the hope that sleepier babies will fall asleep more easily.
The randomized controlled trial involved 43 babies who were between six and 16 months of age and had night-time sleep troubles.
The babies were split into three groups – 14 were placed in the graduated extinction group, 15 in the bedtime fading group and 14 in a control group in which parents were provided with sleep information from a child health survey.
During the trial, parents kept diaries tracking their babies' sleep patterns and the babies' stress levels were measured in the morning and afternoon through a saliva sample that measured cortisol. Mothers also reported their own mood and stress levels.
The researchers found that babies whose parents used the graduated extinction method fell asleep an average of 13 minutes sooner and woke up significantly less during the night compared to the control group.
There were also no significant differences in stress levels among those babies.
Gradisar said all of the babies involved in the study maintained normal cortisol levels throughout the trial period.
Those who were part of the bedtime fading group showed a 10 minute decrease in the time it took babies to fall asleep, compared to the control group. However, this group saw no change in the number of night-time awakenings.
'Natural' for parents to worry about baby crying
Meanwhile, the control group's sleep did show some improvements in nighttime wakefulness and total sleep, suggesting the babies' sleep improved as they matured.
At a 12-month follow-up, no significant differences were found in emotional, behavioural or parent-child attachment issues among all three groups.
"It's natural for parents to worry about having their babies cry at bedtime," Gradisar said.
He told CTVNews.ca in an email that parents often express concerns about attachment issues if a baby's cries are not immediately responded to. But he noted that parents can potentially put their own health at risk when their child continues to frequently wake-up through the night beyond the six-month mark.
"Parents who frequently have their sleep disrupted by their infant's cries would likely experience…elevated levels of daytime sleepiness and fatigue, poor work performance, but more importantly, difficulty regulating their emotions," Gradisar said.
He said mothers are at a two-fold greater risk of developing depression if their child has a persistent sleep problem, which could take months, even years to treat.
"The two sleep techniques we evaluated showed improvements within a week," he said.
Gradisar said a combination of the two sleep approaches studied, starting with bedtime fading and moving onto graduated extinction, if needed, is a good way to approach sleep training.
Sleep consultant Alanna McGinn, founder of the , says many of the parents she works with express concerns about sleep training potentially causing parent-child attachment issues or permanent psychological or behavioural issues.
"It's never easy to hear our kids cry," she told CTVNews.ca. "But having a child who lives in a very loving home…sleep training for a couple of nights is not going to damage that."
McGinn said sleep training isn't solely about the method parents choose to use – whether they opt to use cry-it-out, graduated extinction or a "no-cry" sleep training solution.
Rather, making sure babies are taking age-appropriate naps, following a consistent bedtime routine, creating a comfortable sleep environment and ensuring babies are not going down for bed when they're over-tired all help to limit night-time waking.
"Consistency is key with whatever (method) you choose to use," she said.
McGinn said babies are typically not ready for sleep training until they’re between four-and-a-half to six-months old. Before that time, parents should be consistently responding to their baby's cries.
She noted that while cry-it-out is typically the fastest way to get children to sleep through the night, there are gentler methods to sleep training.
However, she warned that all sleep-training methods, even "no cry" solutions, generally involve some crying on the baby's behalf.
"It's important for parents to understand that at the end of the day, their child is still going to love them in the morning," McGinn said. "I can pretty much guarantee that."
