Stepwise association between degree of immaturity and risk of receiving ADHD medication
TUESDAY, April 19 (HealthDay News) -- Children who are born moderately or extremely preterm may have an increased risk of developing attention-deficit/hyperactivity disorder (ADHD), according to a study published online April 18 in Pediatrics.
Karolina Lindström, M.D., from Sachs Children's Hospital in Stockholm, Sweden, and colleagues analyzed the effect of preterm birth on the risk of ADHD in 1,180,616 children born between 1987 and 2000 from a Swedish cohort study. A follow-up in 2006 identified the proportion of children aged 6 to 19 years who were receiving medication for ADHD. The importance of genetic confounding was estimated in a within-mother-between-pregnancy analysis of a subpopulation of 34,334 offspring whose mothers had given birth to preterm (≤34 weeks) and term infants.
The investigators found that there was an increase in the likelihood of receiving ADHD medication as birth immaturity increased. Infants born at 23 to 28 gestational weeks had an odds ratio of 2.1, which decreased progressively to 1.6 for those born at 29 to 32 weeks, 1.4 for those born at 33 to 34 weeks, 1.3 for those born at 35 to 36 weeks, and 1.1 for infants born at 37 to 38 weeks compared with infants born at 39 to 41 weeks. Similar odds ratios were found for the within-mother-between-pregnancy analysis. The effect of moderate preterm birth on the risk of ADHD increased in those with low maternal education.
"Preterm and early term birth increases the risk of ADHD by degree of immaturity. This main effect is not explained by genetic, perinatal, or socioeconomic confounding, but socioeconomic context modifies the risk of ADHD in moderately preterm births," the authors write.