Expectant mothers are constantly reminded that everything they experience, their baby experiences too. So how concerned should they be about the hair treatments they use?

These treatments––coloring, curling, bleaching and relaxing––use products with chemical ingredients that haven’t been generally evaluated for pregnancy effects, the American Pregnancy Association reports.

The chemicals in these products are applied directly to the scalp and can be absorbed through the skin into the body (in small amounts).

But because manufacturers frequently change formulas of their hair treatment products, limited data is available about how these chemicals affect pregnant women.

What experts suggest is that since moms-to-be only absorb a minimal amount of hair treatment chemicals, this is probably not enough to cause harm during a pregnancy.

But to be totally safe, health care experts advise women not to use permanent hair dyes during the first trimester of pregnancy.

What concerns experts most is pregnant women inhaling chemical fumes. Some treatments use permanent hair dyes that contain ammonia and straightening chemicals. These ingredients release strong fumes that harm a baby’s development.

For pregnant women contemplating a trip to the salon, the American Pregnancy Association suggests the following safety tips to ensure their developing babies remain unharmed:

• Opt for semi-permanent hair dyes or highlights that use dyes enclosed in foil.
• Use ammonia-free products or all-natural vegetable dyes, such as henna.
• Have the treatment done in a well-ventilated area.
• Don’t leave chemicals in hair longer than necessary, and do rinse the scalp thoroughly with water after treatments.
• Do a small patch test to check for allergic reactions before using a product.

The American Pregnancy Association also advises moms-to-be to wait until the second trimester for scheduled hair dye, bleaching or straightening appointments.

And if you’re breast-feeding, rest easy. There’s little evidence to suggest chemicals could taint breast milk.

Ever wonder how a relaxer straightens tresses?  Click here to learn how.