A diagnosis of attention-deficit/hyperactivitydisorder (ADHD) in children may berelated to their mother's smoking duringpregnancy. The study, reported in Pediatrics(August 2005), used data from theDanish government's longitudinal registerson 4000 children born between 1991and 1994. The researchers comparedsmoking habits of the mothers of 170 childrenwho were later diagnosed with ADHDwith 3765 mothers whose children werenot diagnosed with the condition.
The researchers controlled for lowbirth weight of babies, poor newbornhealth status, young maternal age, andlow socioeconomic status. They foundthat smoking mothers were almost 2times as likely to have children withADHD, compared with mothers who didnot smoke during pregnancy. Of the participants,59% of the mothers of ADHDchildren smoked while pregnant, comparedwith 35% of the mothers with non-ADHD children. One key factor thatcould not be determined was whetherpregnant smokers had ADHD themselves,which might make them morelikely to smoke, and which might be thereason for the higher number of childrenwith the disorder in this group.