A study conducted in Finland at the Ruku University Hospital by Mikael Ekblad, found that smoking during pregnancy may increase a child’s risk of developing a psychiatric disorder during childhood and young adulthood.  It was recently presented at the Pediatric Academic Societies’ annual meeting held in Vancouver, British Columbia.


Substantial evidence already exists that smoking during pregnancy puts unborn children at risk for long-term health problems such as asthma, ear infections and respiratory disease.  This study is the first to find a connection between prenatal smoking and an increased risk for mental illnesses, such as attention-deficit/hyperactivity disorder (ADHD) and depression, in the mother’s offspring.


“In our previous study, published in the Journal of Pediatrics in February 2010, we found that prematurely born infants exposed to prenatal smoking had smaller frontal and cerebellar brain volumes than the unexposed infants. These brain regions are important for normal cognitive development,” said Ekblad, a medical student and pediatric researcher.


The researchers obtained information for all children born (more than 175,000) in Finland between 1987 and 1989, as well as their use of psychotropic medications during childhood and as young adults.  They analyzed their medical records on use of psychiatric drugs between 1994 and 2007, using records from Finland’s Social Insurance Institution.  Their mother’s psychiatric hospital care over two decades, between 1969 and 1989 were also evaluated.


Almost 12 percent of the young adults had taken psychotropic drugs, primarily for the treatment of Attention Deficit Hyperactivity Disorder, and of this group, about 19 percent had mothers who smoked during their pregnancies.


The use of psychiatric medication was highest in young adults whose mothers smoked more than a half a pack of cigarettes daily during pregnancy.  The children exposed to smoking before birth had a 32 percent increase in psychiatric drug treatment compared to children whose mothers didn’t smoke during pregnancy, the researchers found. The risk was even higher in the offspring of women who smoked more than a pack a day while pregnant. Their children were 44 percent more likely to use psychiatric drugs than children whose moms didn’t smoke.


Ekblad linked prenatal smoking to the increased likelihood of using psychotropic medications, especially those used to treat attention deficit hyperactivity disorder. The researchers found that exposure to prenatal smoking increased the risk for using all psychotropic drugs, but especially ADHD medications, antidepressants and drugs to treat addiction. The children whose mothers smoked more than a pack of cigarettes a day were 2.5 times more likely to take stimulants for ADHD than kids whose moms didn’t smoke during pregnancy.


He said, “Smoking during pregnancy is still quite common even though the knowledge of its harmful effects has risen in recent years.


“By avoiding smoking during pregnancy, all the later psychiatric problems caused by smoking exposure could be prevented.”


When evaluating for other factors, they found similar risk for medication among boys and girls, after adjusting for other pertinent factors such as mother’s psychiatric care, birth weight and other pertinent factors.



Mikael Ekblad, pediatric researcher, Turku University Hospital, Turku, Finland; May 4, 2010, presentation, Pediatric Academic Societies annual meeting, Vancouver, British Columbia, Canada