My baby at 5 days had jaundice at blood level 18mg/l is that a concern for autism?

My sons was that high it went to 20 but it came right back down, they said it works form the head down and it shouldn't below there knees and then it goes back up the body the way it came down get him in the sun , taker a walk if its cold put him in front of window it helps a lot walk or window with at least clothes as possible... onsie etc