New Research Raises Possibility of Prenatal Screening for Autism

Prenatal screening for autism moves a step closer to reality today as new research has found ways of potentially identifying the condition in unborn babies.

By Murray Wardrop, Telegraph.co.uk

Scientists at Cambridge University discovered that high levels of testosterone in the amniotic fluid of pregnant mothers was linked to autistic traits in their children.
The findings raise the possibility of undertaking tests in the womb to detect the condition, which would allow parents the controversial ability to decide whether to terminate foetuses.

Scientists are now calling for a national debate on the consequences of the screening process, called amniocentesis, which is already used to detect Down's syndrome in unborn babies.

Parents of autistic children are especially critical of testing linked to

Sufferers of the disorder include people with extraordinary abilities in mathematics and music, as well as children who are unable to communicate and require lifelong care.

Critics point out that a prenatal test would not be able to identify such differences in the effects the disorder can have on individuals.

Director of the research team, Professor Simon Baron-Cohen, told the Guardian: "If there was a prenatal test for autism, would this be desirable? What would we lose if children with autistic spectrum disorder were eliminated from the population? "We should start debating this. There is a test for Down's syndrome and that is legal and parents exercise their right to choose termination, but autism if often linked with talent. It is a different kind of condition."

Experts from the university's autism research centre discovered the testosterone link after studying 235 children from birth to the age of eight.

They found that when high levels of the hormone were found, children showed autistic traits such as a lack of sociability and verbal skills by the time they were eight.

Researchers May Have Answers for the Rise in Autism

A study published in the journal Epidemiology this month by Irva Hertz-Picciotto and Lora Delwiche offers some definitive answers to a decades-long debate concerning the rise in autism.

Over the past 20 years there have been increasing reports of a rise in cases of autism. Many considered these reports evidence of an epidemic and pointed to various factors such as environmental toxins to explain the rise in autism. However, there were many other factors that could explain this rise. Among the most frequently cited explanations to discount an actual rise in autism were the methods used to diagnose new cases of autism, inclusion of milder cases of autism, earlier age of diagnosis, and poor methods for estimating prevalence.

Many in the autism community felt these explanations were insufficient and offered counterarguments and reanalyses of datasets. And thus the debate continued with few clear answers.

The study by Hertz-Picciotto and Delwiche evaluated all clients of the Department of Developmental Services Regional Centers in California aged 3 years and older for the period of 1990 through 2006. For children under 3, records from the Early Start Report were used for a similar time period.

The authors controlled for a number of confounds that previous studies failed to do. The interested reader is encouraged to read their study as the description of their methods was very thorough (The Rise in Autism and the Role of Age at Diagnosis. Epidemiology, 20, 84-90). All in all, the study represents the most rigorous analysis of the rise in autism that has been published to date.

Their study found that since the early 1990’s the incidence of autism rose 7 to 8 fold. They discuss that “…changes in diagnostic criteria, the inclusion of milder cases, and an earlier age at diagnosis, during this period suggests that these factors probably contribute 2.2-, 1.5-, and 1.24 – fold increases in autism, respectively, and hence cannot fully explain the magnitude of the rise in autism”. This leaves a 2- to 3-fold increase in the incidence of autism.

The authors conclude “…the current occurrence of autism, a seriously disabling disorder in young children, at rates of greater than 30 per 10,000 individuals – and still rising in California – is a major public health and educational concern”.

We here at CARD would certainly agree.







Dennis Dixon, Ph.D.
Research and Development Manager
Center for Autism and Related Disorders, Inc.