Semi-Permanent and Permanent

• According to the Organization of Teratology Information Services, semi-permanent and permanent hair coloring is safe when pregnant, as long as you take some precautions. Not only should you color your hair in a well-ventilated area, but you should also choose hair color that takes the least amount of time to process, so that you are exposed to the chemical fumes for only a short amount of time and the chemicals have less time to absorb into your skin. L'Oreal offers Perfect 10, which takes only 10 minutes to process and is an excellent choice. If you are still wary about coloring your hair with semi-permanent or permanent color, you can try only highlighting it to hide grays or roots.
  
  

Vegetable Dyes

• If you're still worried about using semi-permanent and permanent hair color while pregnant and want to err on the side of being safe rather than being sorry, you might might try vegetable dyes, which are completely natural and contain no harsh chemicals. You can find vegetable dye hair colors at most health food stores. Check the box for a list of ingredients, though; if you see any chemical names like dihydroxybenzene, know that it's a chemical used in permanent hair color and should not be in vegetable dyes at all.
  
  

Henna

• Henna has been used for dyeing hair for centuries. It is considered very safe for pregnant women, however it only renders one color, which is a deep red, orange color. It could be helpful for someone who has very dark hair and is just looking to get rid of a few grays. Henna can also be messy, but if you go to a hairstylist that specializes in henna coloring, you can get it done. It also needs to stay on the hair for a much longer amount of time than permanent hair color, but since it is a natural dye, it cannot harm your baby.