While I support a proper scientific investigation into the...

While I support a proper scientific investigation into the sharply rising rates of autism, I would hope that all associated factors are considered, and not just vaccination.

In the paper by Visegrady that I have reported, a number of “robust and consistently identified risk factors” associated with autism are listed.

One is higher maternal (and paternal) age. The average age of childbirth for women in the United States since 1970 has risen from 24.5 years to 29.5 years and the percentage of births to women aged 35+ has risen from 8% to 20%. Rising maternal age is a global trend in developed nations. In Germany, for example, just 7.6% of births in 1981 were to mothers aged 35+; that percentage is now 26%.

Another factor positively associated with autism is maternal pre gestational overweight or obesity. The global prevalence of obesity has tripled since 1975 and has more than doubled in women of childbirth age in the US since 1990.

A further factor is maternal hypertension which in turn is positively associated with obesity. Women with a BMI over 30 have a 2-4 x higher risk of pre-eclampsia during pregnancy than women with a BMI of 25 or less.

Gestational diabetes is also associated with autism. The prevalence of gestational diabetes in the US increased by 30% just between 2016 and 2020. Each year, between 5 and 9% of pregnancies in the US are impacted by diabetes. In India, the rate of gestational diabetes is now between 10 and 17%. And yes, rates of autism have been increasing rapidly in India as well.

Maternal use of antidepressants during or prior to pregnancy is another factor that has been observed to be associated with autism, although there is some debate over whether the treatment or the depression is responsible. Prescribing of antidepressants has risen sharply in the last few decades. For example, the rate of antidepressant prescribing during pregnancy in the UK rose 4-fold between 1992 and 2006. There has been a 787% increase in diagnosis in autism in the UK over 20 years.

I have no doubt that another factor related to sharp increases in the prevalence of autism is rising diagnosis, driven by more awareness of the condition, more sensitive screening and financial incentive in diagnosis. For example, on the last point, in Australia the growth in diagnosis of autism is now one of the highest in the world, exceeding the US and UK. In Australia, autism and development delay, which often precedes autism, now accounts for the majority of NDIS participants and the average participant in 2023 received $33,800 per year in NDIS assistance.