I guess it is necessary for him to have high oxygenation in his brain to help the brain cells to proliferate. I am looking forward to your early reply. Your son's case is obviouly a complex one, and well beyond the scope of the forum to answer in the comprehensive way it ideally deserves. Developmental delay is a nonspecific term used to describe any situation where a child's brain fails to mature as rapidly as anticipated. Such delay may affect cognitive functioning, language function, coordination or motor functioning, and social or behavioral functioning, depending on the precise nature of the underlying condition causing the delay.
Autism is an example of the latter.
Unfortunately, there is no way to know how much if any amount of additional oxygen may have helped your son. The insult to his brain responsible for his delay may well have occurred entirely in utero and be beyond any help after birth, howver great or small. At any rate, I think you are wise to not dwell on hypothetical theories and are rightly devoting your attention to helping Eugene now. CT scans will show gross abnormalities of the barin, especially bleeding. MRI scans are generally much more sensitive at detecting more subtle underlying abnormailities of the brain such as malformations of the cortex of the brain or abnormalities in the way developing nerve cells migrated when they first formed.