Here are guidelines for pregnant women about the use of these products, courtesy of the American Pregnancy Association:

• Try to avoid treatments that straighten, bleach, perm or color hair until the second trimester.
• Make sure that any treatment is applied in a well-ventilated area.
• Don't leave hair chemicals in longer than necessary.
• Make sure your hair and scalp are thoroughly rinsed with water after the treatment.
• Always wear gloves when applying these chemicals yourself, and always follow manufacturer directions carefully.
• Try testing on a small patch of hair first, to monitor for any allergic reaction.

-- Diana Kohnle