Study: ADHD Linked to Preterm Birth
Risk for Attention Deficit Hyperactivity Disorder in School Age Children Associated With Premature Birth
ADHD and Preterm Birth
For the study, researchers in Sweden pulled government records for more than a million school children who were born between 1987 and 2000.
They compared data about the children’s births and family lives to prescription drug records.
For the purposes of the study, kids were determined to have ADHD if they had been prescribed at least one stimulant in 2006.
Stimulant medications for ADHD in Sweden may only be prescribed by specialists who are familiar with the disorder.
Overall, 7,605 children had a record of an ADHD medication in the Swedish Prescribed Drug Register, representing about 1% of the boys in the study and about 0.3% of girls.
The researchers, who were from the Karolinska Institute and Uppsala University, tried to tease out the influences of well-known risks factors by controlling for things like maternal age, education, smoking status, single parenthood, government assistance, and a history of psychiatric disorders in the parents.
They also adjusted for low Apgar score, which measures the health of newborns, and small size at birth.
Researchers found that even for moderate prematurity, or birth between 33 and 36 weeks' gestation, and even between siblings, being born early was associated with an increased risk of ADHD.
Absolute Risk Still Low
While that sounds concerning, other researchers who have looked at this question say it’s important to remind parents that most babies born early won’t have any ADHD problems.
“That was something big we wanted to drive home,” says Nicole M. Talge, PhD, an epidemiologist at Michigan State University in East Lansing. Talge published a study in December in the journal Pediatrics that also found a link between ADHD and premature birth, though she says most kids who were born early didn’t have attention problems. “At least 70 to 80 percent had scores that were considered to be in the normal range.”