Mother's place of birth is a risk factor for autism in US-born children, research shows

June 24, 2014
UCLA study: Mother's place of birth is a risk factor for autism in U.S.-born children
Until now, scientists have had a difficult time determining risk factors for autism, other than the mother's age and complications during pregnancy.

(Medical Xpress)—Can the place where a woman is born and raised be a risk factor for autism in her child? According to new research out of UCLA, the answer is yes.

In the U.S., the prevalence of has been reported to be highest among non-Hispanic white children, but a new study from the UCLA Fielding School of Public Health offers evidence that other ethnic groups actually are at a higher risk for the disorder. Using data from racially diverse Los Angeles County, which is home to a large number of recent immigrants, the researchers found that the mother's place of birth is a risk factor for autism among U.S. children.

Specifically, they found that when compared with children born to white American , children of foreign-born women who are black, Central or South American, Filipino and Vietnamese had a higher risk of autism. The same held true for children of U.S.-born African American and Hispanic women. The risks were adjusted for maternal age, education levels, socioeconomic status, whether the families had health insurance and other factors known to influence the diagnosis rate.

The study appears in the current online edition of the journal Pediatrics.

Autism spectrum disorders are complex developmental disorders that affect how a person behaves, interacts with others, communicates and learns. Until now, though, scientists have had a difficult time determining possible prenatal other than the mother's age and complications during pregnancy. However, recent European studies have reported an association between the nation where a woman is born and her children's risk for autism.

"Epidemiology has a long tradition of using migration studies to understand how environmental and genetic factors contribute to disease risk in populations," said Dr. Beate Ritz, the paper's senior author, and a professor and chair of the Fielding School's department of epidemiology. The fact that 22 percent of 6-year-olds born in the United States have immigrant parents opened a unique opportunity for us to consider the influence of nativity, race and ethnicity on the causes of autism spectrum disorder."

The study analyzed birth records for children born in Los Angeles County who had been diagnosed with autism between the ages of three and five from 1998 to 2009. Researchers linked the children to their California birth certificates, which include information about the mother's race, ethnicity and place of birth. In total, 7,540 children with autism were identified from more than 1.6 million births.

Once adjusted, when compared to U.S.-born white mothers, rates were 76 percent higher in of foreign-born black mothers, 43 percent higher in women born in Vietnam, 25 percent higher in women born in the Philippines, 26 percent higher in women born in Central or South America, and 13 to 14 percent higher in Hispanic and black women born in the U.S.

The study suggests that there are several varied reasons that the mother's place of birth is a risk factor. One common thread may be the psychological and physical stresses the mothers experience while relocating, for example, due to escaping war, natural disasters or malnutrition from famine.

"For foreign-born mothers, language and cultural barriers in the U.S., and a lack of access to health care could also have caused an underestimate of autism spectrum disorder in these populations," said Ritz, who is also a professor of neurology and a member of the UCLA Brain Research Institute.

The discovery that the mother's place of origin is a risk factor for childhood autism has important clinical implications, Ritz said. "Our findings suggest that we need to do a better job of early identification and treatment of autism spectrum disorder for these large and diverse immigrant communities who vary in risk, protective factors and access to health care."

Explore further: Moms with lupus more likely to have children with autism, study suggests

More information: "Autism Spectrum Disorders and Race, Ethnicity, and Nativity: A Population-Based Study." Tracy A. Becerra, Ondine S. von Ehrenstein, Julia E. Heck, Jorn Olsen, Onyebuchi A. Arah, Shafali S. Jeste, Michael Rodriguez, and Beate Ritz. Pediatrics peds.2013-3928; published ahead of print June 23, 2014, DOI: 10.1542/peds.2013-3928

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not rated yet Jun 24, 2014
When you crowd any segment of a population into an area where the environment creates high risk factors, of course this problem will show up. These are mostly the very lowest income segment of the nation's population, therefore they cannot afford to live in a pollution inhibiting environment thereby statistically inviting the kinds of problems the author writes about.
not rated yet Jun 24, 2014
What if the common thread was vitamin D?

not rated yet Jun 24, 2014
Wonder if these moms who migrate have their children immunized in their new home countries? Maybe the countries who are tracking this data are welcoming these children with a dose of autism. Is the autism diagnosed prior to immunizations or migration? Maybe our answer is in the middle.
not rated yet Jun 24, 2014
1 in 68 children in US has an autism now (1 in 45 in NJ). That is 30% increase in the diagnosis from 2012, and 72% increase since 2007!!!!!!!!!!! ....It MUST be more to that than simply saying that mother's place of birth, lupus, infections during pregnancy, mother's age, stress, immunization, etc. are the causes! Where is the common sense?? I hope that researchers will find a real and valid causes soon! Maybe we should look closer at our environment - chemicals, pesticides, huge amount of medications people take everyday (are they biodegradable??? or ..when we pee, they go back to our WATER that we use everyday (drink, prepare food with) !!!!

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