Risk Of Autism Rises With Age Of Moms, Dads

Men and women who wait to have
babies later in life may increase their children's risk for autism,
according to a Kaiser Permanente study featured in the April issue of
Archives of Pediatrics & Adolescent Medicine, one of the JAMA/Archives
journals.


The study investigated 132,844 children born at Kaiser Permanente
hospitals in its Northern California region over a five-year period
(1995-1999) and identified 593 children who had been diagnosed with an
autism spectrum disorder (ASD).



Study results show that a mother's and father's risk of delivering a
child with autism steadily increases as they get older. Women ages 40 and
older showed a 30 percent increase in risk for having a child with autism
(1 in 123), when compared to moms between the ages of 25 and 29 (1 in 156).
Men ages 40 and older had up to a 50 percent increased risk of having a
child with autism (1 in 116), when compared to their 25- to 29-year-old
peers (1 in 176).



Advanced age of mothers has been associated with risk of autism in
several, but not all earlier studies, according to study author Lisa A.
Croen, PhD, an epidemiologist at Kaiser Permanente's Division of Research
in Oakland, Calif. The role of a father's age in autism has been less
frequently studied, although advanced paternal age has been associated with
other adverse reproductive outcomes, including miscarriage, childhood
cancers, autoimmune disorders, schizophrenia and other neuro-psychiatric
disorders.



"As men age, there is an increased frequency of new mutations in the
cells that go on to become sperm," said Dr. Croen. "These sporadic
mutations could be related to autism risk. It is possible that non-genetic
factors that are more common in older parents might also account for our
findings."



For reasons not fully understood, autism is on the rise, affecting on
average about one in 150 children born in the United States, according to
the Centers for Disease Control and Prevention, which helped fund the
study. The chronic, life-long condition affects the normal functioning of
the brain, impacting development of social and communication skills.



While the cause of autism is unknown, there is strong scientific
evidence that the condition is genetic. Environmental factors -- such as
infections, medications and pesticides -- are also being investigated for
their possible role in the cause of autism.



Children with autism are four more times likely to be male. According
to the study, children with the disorder were also more likely to have
older, more highly educated and white, non-Hispanic parents.



A growing number of autism cases several years ago caused Kaiser
Permanente physicians and leaders from throughout Northern California to
design a regional program that would best serve the needs of parents and
children. Using best practices, the Regional Program for Autism Spectrum
Disorders (ASD) was established in 2004 under the direction of Pilar
Bernal, MD.
















Today, the regional program includes a team of ASD clinical champions
from all of Kaiser Permanente's pediatric psychiatry and pediatric clinics
in Northern California. It also includes two regional Autism Spectrum
Disorders Centers, currently located in San Jose and Rancho Cordova. A
third center is being planned for the Bay Area.



Research shows that early intervention can greatly improve a child's
development. Kaiser Permanente provides routine autism screening for
newborns to age 2 during well-baby check-ups, allowing pediatricians to
refer very young children to the regional centers who they suspect may have
symptoms of autism.



Dr. Croen notes the study data suggest that advanced maternal and
paternal age are independently associated with ASD risk. Age effects were
found to be independent of birth year and thus not explained by the
increasing age of parents that has been observed in recent years. If the
relationship between parental age and autism is causal, the fraction of
autism in this sample attributable to having a mother or father older than
35 years is 4 percent to 13 percent, Dr. Croen says.



Future investigations are warranted that focus on the identifications
of both genetic and environmental factors that correlate with advanced
parental age, Dr. Croen says.



Interviews with Dr. Croen and a full-text version of the study are
available upon request.



The Kaiser Permanente Division of Research conducts, publishes, and
disseminates epidemiologic and health services research to improve the
health and medical care of Kaiser Permanente members and the society at
large. It seeks to understand the determinants of illness and well being
and to improve the quality and cost-effectiveness of health care.
Currently, the center's 400-plus staff is working on more than 250
epidemiological and health services research projects.



Kaiser Permanente is America's leading integrated health plan. Founded
in 1945, it is a not-for-profit; group practice prepayment program
headquartered in Oakland, Calif. Kaiser Permanente serves the health care
needs of more than 8.6 million members in nine states and the District of
Columbia. Today it encompasses the not-for-profit Kaiser Foundation Health
Plan, Inc., Kaiser Foundation Hospitals and their subsidiaries, and the
for-profit Permanente Medical Groups. Nationwide, Kaiser Permanente
includes approximately 156,000 technical, administrative and clerical
employees and caregivers, and more than 13,000 physicians representing all
specialties.


Kaiser Permanente

kaiserpermanente/