A child aged 4 months or older is sleeping in his room and taking longer to sleep.
The study, which includes senior researcher Ian Paul, found that babies aged 4 months and older who sleep with their parents have shorter sleep times and less sleep than babies who sleep separately.
The study was based on data from about 230 families at random for two years.
The study found that babies sleeping in their own room more than 4 months old had an average of 10.5 hours, while babies sleeping with their parents slept an average of 9.5 hours.
A child who sleeps alone sleeps for nine consecutive hours, while a child sleeping with his parents slept for 8.3 hours.
The American Academy of Pediatrics, on the other hand, contrasts with the results of Ian Paul's research, recommending that parents and babies sleep together until 6 months of age.
The American Academy of Pediatrics advocates that children should sleep with their parents in a place other than a bed for at least six months and that they can reduce the risk of sudden infant death syndrome.
Paul argued that the Pediatric Society might have focused only on preventing the risk of sudden infant death syndrome with a biased perspective when examining data.
Jodie Mindel, deputy director of the Philadelphia Children's Hospital Sleep Center, also agreed with Paul's study. "Sleeping separately for the baby and the parent has a positive effect on family well-being and on baby safety and development," he said.