Male age and fertility

Ciara
My SO is 42; I am 30. We both have been very engaged in baby talk lately and decided to wait 2-3 years before TTC. However, I am concerned his age may effect the health of our baby, as many studies have come out recently linking autism to dads over 40. We are considering banking sperm now for future use, but I'd really like to conceive naturally. Any thoughts, suggestions or experiences on the matter?
Additionally, he had a fertility test done about 9 years ago and was told he had low sperm count which makes me concerned that if we start TTC in 2-3 years, it may take 4-5, or may not happen at all and I'll wish we had banked. 
Would love any thoughts on the matter.