New parents who struggle to get babies to sleep through the night may not be doing anything wrong, according to new research suggesting that many apparent sleep problems are really part of normal infant development.
For example, the study found that 6-month-old babies still take 20 minutes, on average, to fall asleep. And by age 2, toddlers still wake up an average of once each night.
The study also found that a lot of variation is normal, said lead author Dr. Juulia Paavonen, of Helsinki University Hospital in Finland.
“Now we know that the individual differences are very large, and that patterns relating to falling asleep, waking up, staying awake at night, and sleeping rhythms often develop at different rates,” Paavonen said by email.
Parents often fret about how well infants sleep because constant nighttime awakenings can disrupt everyone in the home and fuel concerns that babies are not developing normally. For first-time parents in particular, irregular sleep can seem like a sure sign that babies are sick, or hurting or hungry.
For the study, researchers surveyed parents of nearly 5,700 children about how well babies slept during their first two years of life to get a sense of what types of sleep issues worried parents – and what might be cause for concern versus simply an exhausting part of normal infant development.
Overall, about 40% of parents were concerned about babies’ sleep when kids were 8 months old, the study found.
Children’s sleep gradually became more stable and consistent over time, the researchers report in Sleep Medicine. Babies and toddlers generally slept between nine and 10 hours at night, but the amount of daytime sleeping declined from about five hours total for infants to about two hours for toddlers.
As daytime naps decreased from two to one, on average, and kids slept for fewer total hours during the day, they also reduced their total sleep time to about 12 hours by the time they reached their second birthday.
It’s not as common, however, for babies to take more than 40 minutes to fall asleep or to have nighttime awakenings of an hour or longer by age 8 months, the study found.
It’s also unusual for babies to be awake for more than 45 minutes at a time during the night by 12 months, or for more than a half-hour by 18 months.
These might be circumstances when it makes sense for parents to check with a pediatrician to see if there’s anything unusual making it harder for babies to sleep, the study team concludes.
“It is important to follow a baby’s growth to know if they are healthy,” said Dr. Joanna MacLean, a sleep specialist at the University of Alberta in Edmonton, Canada, who wasn’t involved in the study.
“Given a baby’s job is to eat, sleep, and grow, growth is a useful indicator of health problems,” MacLean said by email. If growth is normal, patterns that seem like sleep problems to parents might also be normal, MacLean said.
Parents should also avoid waking a sleeping baby, because that’s when a lot of brain development happens, said Gina Poe, a researcher at the University of California, Los Angeles who wasn’t involved in the study.
“There is important work ongoing in the sleeping brain,” Poe said by email.
Setting consistent sleep routines can help babies get the rest and development time that they need, advised Valerie Crabtree of St. Jude Children’s Research Hospital in Memphis, Tennessee.
This works best when parents start in early infancy, Crabtree, who wasn’t involved in the study, said by email.
“Even for newborns, parents can begin to have dim lighting and less interaction at night and brighter, even natural light during the daytime with more activity and interaction,” Crabtree advised.
Putting newborns in pajamas at a consistent bedtime also helps.
“As early as is possible, try placing the baby in the crib drowsy but not fully asleep,” Crabtree added. “This helps babies learn to put themselves to sleep and helps them return themselves to sleep after normal awakenings.”