While there is little in the way of scientific information on the safety of perming or relaxing your hair during pregnancy, perhaps the most convincing evidence against the their use comes directly from hairdressers. Most say that because pregnancy hormones frequently interfere with, or even change, the way your hair reacts to perm or relaxing solutions, you could easily end up with a look that is quite opposite of what you expected. Hair can get frizzy or straight instead of curly, or kinky and frizzy instead of straight. So forgo the perm or straightening for now - and opt for a style that's easy to manage without the extra chemical treatments.
Learn More About Safe Choices for Your Baby• Things You Can and Can't (or Shouldn't) Do During Pregnancy
• Retinol and Hyaluronic Acid in Beauty Products
• Ten Tips for Avoiding Excess Pregnancy Weight Gain
Colette Bouchez is an award winning medical journalist with more than twenty years experience. She is the former medical writer for the New York Daily News, and the top selling author of The V Zone, co-author of Getting Pregnant and upcoming book, Your Perfectly Pampered Pregnancy. Currently a daily medical correspondent for HealthDay News Service/The New York Times Syndicate, and WebMD, her popular consumer health articles appear daily online, as well as in newspapers nationwide and in Europe and Japan. She is a regular contributor to USAToday.com, ABCNews.com, MSNBC.com and more than two dozen radio and television news stations nationwide. She lives in New York City.
Excerpted from Your Perfectly Pampered Pregnancy
Copyright © Colette Bouchez. Permission to republish granted to Pregnancy.org, LLC.

Comments
my doctor said it was ok for me to dye my hair in nd and 3rd trmesters as well
Well, your general advise that dying your hair should be harmless to your unborn child is in complete opposition to everything else I have read.
Hardly any dying products (including henna!) is without either parabens or other chemicals that can hurt your child.
Either by affecting it's natural hormones - thus risking messing up the development of its genitals or causing girls get their periods or develop breasts when they are as young as six years old. Or by increasing the risk that it develops allergies.
I find your advise very misleading and was shocked to see it!
Otherwise I enjoy this site and love pregnancy calender!