Autism link to firstborn of older parents

[Guest guest]

http://news.scotsman.com/uk/Autism-link-to-firstborn-of.4630550.jp

Autism link to firstborn of older parents

Date: 26 October 2008

By Liz Longden

FIRSTBORN children of older parents have three times as much chance

of being diagnosed with autism than later born children of younger

parents, new research has revealed.

A study of 240,000 teenagers carried out by researchers in the US has

found a strong link between the likelihood of developing the

condition and a higher age of parents.

Mothers aged 35 and over were cited as having a 30% higher risk of

having an autistic

child than mothers in their twenties, while for fathers in their

forties and over the risk was estimated to be even greater at around

40% higher when compared with fathers aged under 30.

The study also suggested that later born children were less likely to

be afflicted with autistic disorders than firstborn offspring.

The research team behind the study has claimed their work

provides " the most compelling evidence to date that autism risk

increases with both maternal and paternal age, and decreases with

birth order " .

The study, published in the American Journal of Epidemiology, has

been hailed as a possible explanation for the apparent increase in

incidence of the condition in the western world, where social trends

mean increasing numbers of couples put off having children until

later in life, and tend to opt for smaller families – meaning a

higher proportion of babies are firstborn or only children.

There is no clue to suggest why parental age should increase the risk

of a child being autistic, but the authors suggest the sperm of older

fathers could be more likely to pass on genetic mutations, while

older mothers might be more susceptible to chromosome alterations.

Another theory suggests that older parents may be more likely to spot

developmental difficulties in their children, and therefore more

likely to seek help and a formal diagnosis.

Firstborn children are also more prone to suffer from other childhood

disorders, including type I diabetes. One theory to explain the

phenomenon is the " hygiene hypothesis " , which suggests that first-

time parents are more protective and expose their children to fewer

infections in early childhood, making them likely to develop

autoimmune diseases.

[Guest guest]

>

" hygiene hypothesis " , which suggests that first-

> time parents are more protective and expose their children to fewer

> infections in early childhood, making them likely to develop

> autoimmune diseases.

>

Oh good, so let's all expose babies to germs and stop keeping them

clean, is it? Dirt will make public health better.

Bit of history ..

[Guest guest]

The article stated: " ... <snip> ... " hygiene hypothesis " , which

suggests that first-time parents are more protective and expose their

children to fewer infections in early childhood, making them likely

to develop autoimmune diseases ... <snip> ... "

maurice wrote: " Oh good, so let's all expose babies to germs and stop

keeping them clean, is it? Dirt will make public health better. Bit

of history ... "

Not that I am agreeing or disagreeing with the " hygiene hypothesis "

however it is a fact that mothers are morehypervigilant with their

first-born than with subsequent offspring mostly because they are

experiencing motherhood for the first time.

First-time drivers are hypervigilant until they get the hang of

things.

First-time employees experience a greater source of stress in terms

of wanting to get everything right at the job than they are at

subsequent jobs.

There's a reason why past generations held resentments against the

first-born and that's because it was perceived -- and true in most

cases -- that by virtue of being the first-born, the first-born

received better treatment than subsequent offspring and sometimes

better treatment than the spouse even.

The hypothesis doesn't mean that we should be dirty/dirtier in order

to make public health better. It means that parents become more lax

with regards to hypercleanliness with subsequent children in the

family which may be why more first-born children develop auto-immune

disorders in life.

Raven