Im a stylist and its totally fine (:
I've done all over and highlights and have 3 perfect babies :) I just dont do it in the 1st trimester to b safe and always in a well ventilated area
I've asked every hair stylist and my Dr and they all say highlights are fine just nothing that seeps in your scalp.. even a few girls do there whole head and there babies were full term and healthy :) if you do let us kniw!