Babies exposed to alcohol in the womb and those who are small at birth develop sleep problems as eight-year-olds, says a new study.
Poor sleep and sleep disturbances in children are associated with obesity, depressive symptoms and attention deficit hyperactivity.
Principal investigator Katri Rikkonen, psychologist at the University of Helsinki, Finland, said even low levels of weekly prenatal exposure to alcohol have adverse effects on sleep quantity and quality during childhood.
Children exposed to alcohol in the womb were 2.5 times more likely to have a short sleep duration of 7.7 hours or less and 3.6 times more likely to have a low sleep efficiency of 77.2 percent or less across all nights.
Smaller body size at birth was also associated with poorer sleep.
In addition, children with short sleep duration were more likely to have been born via caesarean section than were children sleeping longer (23.1 percent versus 8.4 percent respectively).
The study was based on data from 289 children born normally between March and November 1998. Sleep duration and sleep efficiency (actual sleep time divided by the time in bed) were measured objectively by actigraphy at eight years for an average of 7.1 days.