You can’t dye your hair when you’re pregnant
“The main concern with dyeing your hair during pregnancy is the risk associated with inhaling ammonia, not the risk of it being absorbed into your scalp,” says Carrie Ann Terrell, MD, an OB-GYN and professor at the University of Minnesota. “But the levels of ammonia are so low that it’s not a problem, especially if you go to a salon, which will have industrial strength ventilation.”