Babies who get less than 12 hours of sleep a day face twice the risk of being overweight as preschoolers.

And, some parents may inadvertently contribute to their child's sleep problems by taking steps intended to soothe the child that, in reality, lead to disrupted sleep.

That's the conclusion of two reports in April's special issue of the Archives of Pediatrics & Adolescent Medicine, which is devoted to children and sleep.

The combination of too little sleep and too much TV is associated with markedly elevated risk of obesity, explained Dr. Elsie M. Taveras, an assistant professor of ambulatory care and prevention at Harvard Medical School and lead author of the first study.

Our findings clarify the long-debated relationship between parental behaviors and childhood sleep disturbances," the authors concluded. They suggest that co-sleeping and other uncommon parental behaviors have negative consequences for future sleep and are thus maladaptive."

Sleep problems in schoolchildren with ADHD are extremely common and strongly associated with poorer quality of life, daily functioning and school attendance in the child and poorer caregiver mental health and work attendance, wrote the researchers, who were headed by Valerie Sung, of the Centre for Community Child Health in Parkville.

Implementation of a sleep intervention in children with ADHD could feasibly improve outcomes beyond treatment of ADHD alone. It is possible that such intervention could reduce the need for medication in some children, they added.