I have a book with a section on this..and here is what they say (yes i am going to type it all out)
The top section is a bit shorter..but i typed the bottom section out just in case..hope this helps..its took me a while
'I was about to go for my colouring appointment, when i heard from a friend that hair dyes can cause birth defects, is this true?'
Though some extra prudent doctors still advise their patienits to stay away from all hair dyes when they are expecting, studies have not linked these products to birth defects. So little of the chemicals in the dye is absorbed through the skin, its not likely that it would have any adverse effect.
But, while you may not have to worry about the impact on your baby if you continue colouring your hair, you may have to worry about the impact on your appearance. For hormonal reason, your hair may react differently when your expecting - leaving you with a colour you may not have expected.
'my hair is starting to lose all of its body and its flat and limp. Is it safe for me to get a permenant?'
Though the pregnant belly is the most obvious physical effect a gestating fetus has on its mother, it's by no means the only one. The changes are evident everywhere - from the palms of the hands (which may temporarily turn a ruddy red) to inside the mouth ( gums may swell and bleed). The hair is no exception. It can take a turn for the better (when lucklustre hair suddenly sports a brilliant shine) or for the worse (when once bouncy hair goes limp).
Ordinarily, a permanent or a body wave might be the obvious answer to hair that has taken a wrong turn, but it isn't during pregnancy. For one thing, hair responds unpredictably under the influence of pregnancy hormones; a permanent might not take at all, or might result in an unflattering frizz instead of bouncy waves. For another thing, the chemical solutions used in permenants are absorbed through the scalp into the bloodstream, so there are questions about the safety of their use during pregnancy.
So far, studies of the effects of chemicals on the fetus have been extremely reassuring; no like has been found between the use of premenants and the development of birth defects. But since more studies will be necessary before these substances are completely exonerated, the very cautious may wish to stay 'straight' untill after delivery. Don't be concerned, however, about a permenant you already had - the risk is only theoretical, and certainly not worth worrying about.