hello and welcome to healthcare magic community . To tell you straightforward , in my practice I allow women to dye their hair , after first trimester , so to be on even safer side . Although little data is available , dyes are considered safe in pregnant women because very minute amount absorbs in skin and you may apply highlights to prevent dye reach your scalp . In my practice I have seen plenty of women who applied dye on their hair while pregnant and had normal babies . however , use gloves , throughly wash hair after application of dye . Hope I have answered your question . Do ask follow up questions if needed .Best of luck .