Is your baby sleeping enough? Less than ten hours sleep leaves toddlers more likely to develop emotional and behavioural problems says a new study.
In a long-term study of 32,662 pairs of mothers and children in Norway, toddlers who slept less than 10 hours a night or woke frequently at night tended to have more emotional and behavioural problems at age five.
The mothers were made to fill out questionnaires when they were 17 weeks pregnant, when the child was 18 months old and again when the child was five years old.
Mothers rated 99 child behaviours on a scale from 'not true' to 'very true' and reported how long the child slept in a 24-hour period and how often he or she woke up during the night.
At 18 months, almost 60 percent of toddlers were sleeping for 13 to 14 hours per night and about two percent were sleeping for less than ten hours per night.
About 3 percent of toddlers woke three or more times per night. Most children woke a few times per week or less.
The researchers observed that the toddlers who slept less than 13 hours per night often also had emotional or behavioral problems at the same age.
The researchers accounted for mother's age, education level, duration of pregnancy and number of other children and for the child's birth weight and sex, and found that those who slept less than ten hours per night and those who woke three or more times per night at 18 months were more likely to have emotional or behavioral problems at age five.
The risk was higher for problems, like being emotionally reactive, anxious or depressed, than for problems, like attention deficit or aggression.
'Although it is difficult to tease out causality from observational studies, this longitudinal study does suggest that inadequate sleep in early childhood increases the risks for later emotional and behavioral problems,' said Michelle M. Garrison of Seattle Children's Research Institute in Washington, who wrote an editorial about the research.