Oxygen Deprivation Before Birth and Attention Deficit Hyperactivity Disorder
Children who had in-utero exposure to situations during which the brain is deprived of oxygen, were significantly more likely to develop attention deficit hyperactivity disorder later in life as compared to unexposed children
According to a Kaiser Permanente study published in the journal Pediatrics, these findings suggest that events in pregnancy may contribute to the occurrence of ADHD over and above well-known familial and genetic influences of the disorder.
The population-based study examines the association between IHC and ADHD. Researchers examined the electronic health records of nearly 82,000 children ages 511 years old and found that prenatal exposure to IHC especially birth asphyxia, neonatal respiratory distress syndrome and preeclampsia was associated with a 16 percent greater risk of developing ADHD.
Specifically, exposure to birth asphyxia
was associated with a 26 percent greater
risk of developing ADHD, exposure to
neonatal respiratory distress syndrome was
associated with a 47 percent greater risk,
and exposure to preeclampsia (high blood
pressure during pregnancy) was associated
with a 34 percent greater risk.
The study also found that the increased
risk of ADHD remained the same across
all race and ethnicity groups.
“Previous studies have found that hypoxic injury during fetal development leads to significant structural and functional brain injuries in the offspring,” said study lead author Darios Getahun, MD, PhD, of the Kaiser Permanente Southern California Department of Research & Evaluation. “However, this study suggests that the adverse effect of hypoxia and ischemia on prenatal brain development may lead to functional problems, including ADHD.”
Research also found that the association between
IHC and ADHD was strongest in preterm births.
Deliveries that were breech, transverse (shoulder-first)
or had cord complications were found to be associated
with a 13 percent increased risk of ADHD.
These associations were found even after
controlling for other potential risk factors.
“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,” said Dr. Getahun. “We suggest future research to focus on pre- and post-natal conditions and the associations with adverse outcomes, such as ADHD.”
During critical periods of fetal organ development, IHC may result in a lack of oxygen and nutrient transport from the mother’s blood to fetal circulation. The result may be compromised oxygen delivery to tissues and cerebrovascular complications. However, this study suggests that the adverse effect of hypoxia on prenatal brain development may lead to functional problems, including ADHD.
In 2005, the Centers for Disease Control and Prevention estimated the annual cost of ADHD-related illness in children under 18 years of age to be between $36 billion and $52.4 billion, making the condition a public health priority. In 2010, approximately 8.4 percent of children ages 3 to 17 had been diagnosed with ADHD. For about half the affected children, the disease persists into adulthood, according to CDC statistics. Symptoms of ADHD in children may include attention problems, acting without thinking, or an overly active temperament.
This study is part of Kaiser Permanente’s ongoing research to understand the relationship between prenatal conditions and adverse medical outcomes.
Earlier this year, Kaiser Permanente researchers
found that in-utero exposure to relatively high
magnetic field levels was associated with a
69 percent increased risk of being obese or
overweight during childhood compared to
lower in-utero magnetic field level exposure.
A Kaiser Permanente study conducted last year
found exposure to selective serotonin reuptake
inhibitor antidepressants in early pregnancy
may modestly increase the risk of
Kaiser Permanente can conduct transformational health research in part because it has the largest private patient-centered electronic health system in the world. The organization’s electronic health record system, Kaiser Permanente HealthConnect®, securely connects 9 million people, 611 medical offices and 37 hospitals, linking patients with their health care teams, their personal health information, and the latest medical knowledge. It also connects Kaiser Permanente’s researcher scientists to one of the most extensive collections of longitudinal and medical data available, facilitating studies and important medical discoveries that shape the future of health and care delivery for patients and the medical community.
Other study authors included: George G. Rhoads, MD, MPH, and Kitaw Demissie, MD, PhD, of the University of Medicine and Dentistry of New Jersey School of Public Health Department of Epidemiology; Shou-En Lu, PhD, of the UMDNJ School of Public Health Department of Biostatistics; Michael J. Fassett, MD, of the Kaiser Permanente West Los Angeles Medical Center Department of Maternal-Fetal Medicine; Deborah A. Wing, MD, of the University of California, Irvine Department of Obstetrics-Gynecology; and Steven J. Jacobsen, MD, PhD, and Virginia P. Quinn, PhD, of the Kaiser Permanente Southern California Department of Research & Evaluation.
Original article: http://xnet.kp.org/newscenter/pressreleases/nat/2012/121012-prenatal-adhd-causes.html