In general, it appears to be safe to color your hair during pregnancy, although there are no scientific studies that have conclusively determined this. There are some things you can do to minimize the potential risks: dye should avoid contact with your scalp, if possible; consider highlights (the dye solution does not contact the scalp and is covered in foil); wait until after the first trimester to color your hair.
More from The Bump Editors: During your first trimester, you can alternately try an all-natural hair color like henna. Later in your pregnancy, cut back on chemicals in easy ways by looking for dye with little or no ammonia or peroxide. If you color your own hair, pick the brand with the least number of chemicals on the label, work in a well-ventilated room, and wear gloves to keep the chemicals from passing through your skin. If you go to a salon, ask for the earliest possible appointment to minimize your exposure to chemicals.