Decrease risks. Maybe the question should be how can we minimize our chances. We can not ignore environmental factors and the ammount of chemicals in our life. How is your diet? Do you find yourselves eating fast food frequently? How much toxins are you exposed to? It is probablyi mportant to "detoxiify" our bodies prior to conception, some studies strongly suggest this link, and to some medication types.
1/60-1/100. The risk of autism ranges from 1 in every 60 to 1 in every 100 children. There is a greater risk in families with autoimmune diseases already present. The risk is higher in boys than girls.
Depends. 1.53 per 1000 or about 1-2% for autism. 6 per 1000 or about 6% for PDD in the US. If there are siblings with autism, the risk increases. If the child is premature, the risk increases.