A new study reveals that pregnant mothers who are exposed to smoking have greater possibility of having children with sleeping disorders, from birth till the age of 12 yrs.

Previously few studies have supported that abuse during pregnancy is linked with physical and behavioral problems in children but now this new study shows an association of sleeping problems in children with parental exposure to cocaine, alcohol, opiates, marijuana and nicotine.

Researchers have examined 808 American children between 1 month and 12 yrs of age. They found that out of 808, 374 were exposed to cocaine or opiates before birth while other 434 were not.

Researchers have categorized three periods to analyze children's sleep, and asked mother's or other caretakers of these children to report any kind of difficulty they face in falling asleep and staying asleep in the following periods: one month to four years of age; five to eight years, and nine to 12 years.

Finally, above findings show that mother's exposure to nicotine or cigarette smoking is the only unique cause for sleeping problems in children and this association remain the same even after taking into accounts other factors such as socioeconomic status, marital status, physical abuse, prenatal medical care, and postnatal cigarette smoke exposure.