Ok your all prob going to slap me ...but .... with my son i never washed any of the baby clothes before he wore them unless they were hand me downs/2nds. Anything new was not washed i never had a problem with baby wearing them either. To me the thought of washing all those clothes & knowing me ruin them all is just a waste. I'll be doing enough washing after baby is here i certainly ain't starting on it all now. I've left everything with labels on just in case i need to take them back & they are all wrapped so no dust or anything on them. I know someone here will mention something about the chemicals on the clothing but i've never heard loads of babies having problems, I'd be more inclined to say its that individual baby who has a reaction or is more sensitive to them .
Its not " highly common " for them to have reactions, Or if it is it isn't where i am , never heard of a baby yet having a reaction so i wont be washing all the new stuff