MONDAY, Dec. 10, 2012 (HealthDay News) -- Children who were deprived of oxygen in the womb or during birth are more likely to develop attention-deficit/hyperactivity disorder (ADHD), a new study says.
Kaiser Permanente researchers found oxygen deprivation may play a greater role in the prevalence of ADHD than other genetic or familial risk factors for the condition. They noted their findings could help doctors identify and treat children at greater risk for ADHD.
"Previous studies have found that hypoxic injury during fetal development leads to significant structural and functional brain injuries in the offspring. However, this study suggests that the adverse effect of hypoxia and ischemia on prenatal brain development may lead to functional problems, including ADHD," study author Dr. Darios Getahun, of the Kaiser Permanente Southern California department of research and evaluation, said in a news release. "Our findings could have important clinical implications. They could help physicians identify newborns at risk that could benefit from surveillance and early diagnosis, when treatment is more effective."
The researchers analyzed the electronic health records of almost 82,000 children ranging in age from 5 to 11. They found that those who were oxygen deprived before birth had a 16 percent greater risk for developing ADHD, while oxygen deprivation during birth was associated with a 26 percent greater risk for the disorder.
The researchers added that neonatal respiratory distress syndrome was associated with a 47 percent greater risk, and children with exposure to preeclampsia (high blood pressure during pregnancy) had a 34 percent higher risk for the condition.
The link between ADHD and oxygen deprivation was strongest in premature births. After taking gestational age and other risk factors into account, the study also revealed children whose deliveries were breech, transverse (shoulder-first) or involved cord complications had a 13 percent higher risk for ADHD.
The researchers noted the link between ADHD and oxygen deprivation applied to children of all races and ethnicities.
While the study showed an association between oxygen deprivation in the womb and ADHD, it did not prove cause-and-effect.
"We suggest future research to focus on pre- and post-natal conditions and the associations with adverse outcomes, such as ADHD," Getahun added.
In 2005, the U.S. Centers for Disease Control and Prevention estimated the annual cost of ADHD-related illness in children could be as high as $52.4 billion. In 2010, 8.4 percent of children between the ages of 3 and 17 were diagnosed with ADHD.
The study was published online Dec. 10 in the journal Pediatrics.
The U.S. Centers for Disease Control and Prevention provides more information on ADHD.