Having the correct amount of oxygen delivered to growing organs and cells of the fetus is important to healthy fetal development, but researchers at Kaiser Permanente suggest oxygen levels are important in functional development as well. Research suggests that low levels of oxygen delivered to the fetus may be a precursor or possible cause of attention deficit hyperactivity disorder (ADHD) or at least a contributing factor in the development of the condition later in life.

Preeclampsia, birth asphyxiation and neonatal respiratory distress syndrome are three of the more common causes of reduced oxygen or oxygen deprivation to the fetus. All three are associated with negative developmental side effects, including ADHD. Researchers found a 26-percent increase in ADHD in children who suffered birth asphyxia, a 34-percent increase in cases of preeclampsia and a 47-percent increase in children born after experiencing neonatal respiratory distress syndrome. The lack of oxygen, particularly to the brain, is thought to be the cause of the increased risk of ADHD, but a definitive connection/cause has not been stated by researchers involved with the study.

While not all children who experienced oxygen deprivation in-utero will develop ADHD, doctors can use the results of this study to guide future health care. Children noted as being in a high-risk category for ADHD as a result of oxygen deprivation are watched more closely for symptoms of ADHD. If the condition is found early, treatment and control are more effective leading to improved outcome throughout childhood and into adulthood.
It is noted in the study that ADHD is also associated with genetic and familial factors. Oxygen deprivation is not a definitive cause or the sole contributing factor to the development of ADHD. Some cases are never linked with a definitive cause.

Source: Darios Getahun, George G. Rhoads, Kitaw Demissie, Shou-En Lu, Virginia P. Quinn, Michael J. Fassett, Deborah A. Wing, and Steven J. Jacobsen. In Utero Exposure to Ischemic-Hypoxic Conditions and Attention-Deficit/Hyperactivity Disorder. Pediatrics, December 10, 2012 DOI: 10.1542/peds.2012-1298

http://pediatrics.aappublications.org/content/131/1/e53